CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63/222,726, titled “BUFFER TANK SEPARATION AND HOMOGENIZATION SYSTEM,” filed on July 16, 2021, U.S. Provisional Application No. 63/222,738, titled “URINE AND WASTEWATER TREATMENT SYSTEM,” filed on July 16, 2021, U.S. Provisional Application No. 63/222,740, titled “VOLUME REDUCTION SOLIDS TREATMENT SYSTEM,” filed on July 16, 2021, U.S. Provisional Application No. 63/222,728, titled “TWO-CHAMBER COMBUSTION SYSTEM,” filed on July 16, 2021, and U.S. Provisional Application No. 63/338,998, titled “HUMAN WASTE COLLECTION AND SEPARATION SYSTEM,” filed on May 6, 2022, the entire contents of all of which applications are hereby incorporated herein by reference.

BACKGROUND

[0002] An estimated 4.5 billion people worldwide do not have access to safe, affordable sanitation systems. High levels of child death and disease have been linked to oral fecal contamination where pathogen laden fecal matter enters the food or water supply. Non-sewered sanitation systems are needed where traditional sanitary sewer systems are unavailable or impractical.

SUMMARY

[0003] Disclosed herein is a non-sewered single unit toilet system, comprising: a frontend separation system, a buffer tank separation system, a liquid waste treatment system, and a solids waste treatment system. The non-sewered single unit toilet system is configured to produce a useable water and pathogen free solid waste. In some examples, the pathogen free solid waste can be reduced to ash in a two-chamber combustion system.

[0004] The frontend separation system comprises: a vessel comprising a main outlet, the vessel configured to receive human waste comprising at least one of: urine and feces; a flush tank configured to deliver a volume of flush water to the vessel to form a combined waste with the human waste within the vessel; and a solids separator configured to evacuate the combined waste from the vessel and separate the combined waste into a separated solids portion and a separated liquid portion and the separated solids portion comprising mostly solids and some fluid and the separated liquid portion comprising mostly fluid with some solids.

[0005] The buffer tank separation system comprises: at least one inlet comprising a first inlet and a second inlet, the first inlet configured to receive the separated liquid portion of the combined waste, the second inlet configured to receive the separated solids portion of the combined waste; a liquids collection tank comprising a liquids outlet; a solids collection tank comprising a solids outlet; and a belt separator positioned to receive an input stream via the at least one inlet onto the belt of the belt separator, the input stream comprising at least one of: the separated solids portion and the separated liquids portion, the belt separator configured to deliver a solids portion of the input stream to the solids collection tank and to deliver the liquids portion of the input stream to the liquids collection tank.

[0006] The liquid waste treatment system configured to receive liquid waste collected in the liquids collection tank, comprising: an air blower configured to blow air into the liquid waste to reduce the density of the liquid waste and to generate crossflow; a filtration unit comprising an ultra-filtration stage and a reverse osmosis stage, the reverse osmosis stage configured to receive a first permeate from the ultra-filtration stage and deliver a usable water.

[0007] The solids waste treatment system configured to receive a feces slurry, the feces slurry comprising the solids waste collected in the solids collection tank, comprising: a pasteurizer configured to receive a slurry batch and heat the slurry batch at an elevated temperature for a time period to produce a pathogen free slurry; a mechanical dewatering press configured to compress the pathogen free slurry to separate a liquid phase from a volume reduced solid waste, the volume reduced solid waste being formed into a feces cake; and a drying tunnel comprising a conveyor housed and an air duct system, the air duct system configured to propel forced air over the feces cake.

[0008] In some aspects, in the non-sewered toilet system, at least the solids separator, the buffer tank separation system, the liquid waste treatment system, and the solids waste treatment system are housed in a single unit. In another aspect, the disclosed non-sewered toilet systems include or are configured to be used with a two-chamber combustion system, and the two-chamber combustion system can passively and continually dry a batch of feces cakes and/or ignite biofuel in a lower chamber of the combustor, and burn the batch of feces cakes in an upper chamber of the combustor. Also disclosed are methods of treating human waste using the non-sewered toilet system disclosed herein.

[0009] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, with emphasis instead being placed upon clearly illustrating the principles of the disclosure. In the drawings, like reference numerals designate corresponding parts throughout the several views.

[0011] FIG. 1 illustrates an example schematic of a volume reduction non-sewered single unit toilet system according to various embodiments described herein.

[0012] FIG. 2 illustrates an example method for human waste separation using volume reduction non-sewered single unit toilet system of FIG. 1 according to various embodiments described herein.

[0013] FIGS. 3 A and 3B illustrate schematic diagrams of example frontend separation system of the volume reduction non-sewered single unit toilet system of FIG. 1 according to various embodiments described herein.

[0014] FIG. 4 illustrates an example solids separator for a frontend separation system shown in FIGS. 3A and 3B according to various embodiments described herein.

[0015] FIG. 5 illustrates a cross section of a frontend solids separator of FIG. 4 according to various embodiments described herein.

[0016] FIG. 6 illustrates the separation of the solids and liquids within the solids separator of FIG. 4 according to various embodiments described herein. [0017] FIG. 7 illustrates an example method for human waste collection and separation according to various embodiments described herein.

[0018] FIG. 8 illustrates an example schematic diagram of a buffer tank separation and homogenization system of the volume reduction non-sewered single unit toilet system of FIG. 1 according to various embodiments described herein.

[0019] FIGS. 9A-9C illustrate perspective and side views of an example belt separator for the buffer tank separation and homogenization system of FIG. 8 according to various embodiments described herein.

[0020] FIG. 10 illustrates an example buffer tank separation and homogenization system of FIG. 1 according to various embodiments described herein.

[0021] FIG. 11 illustrates cross-sectional view of the buffer tank separation and homogenization system of FIG. 10 according to various embodiments described herein.

[0022] FIG. 12 illustrates an example method for using a buffer tank separation and homogenization according to various embodiments described herein.

[0023] FIGS. 13 A- 13D illustrate example flow and separation for various waste events using the buffer tank separation and homogenization system according to various embodiments described herein.

[0024] FIG. 14 illustrates an example schematic diagram of a urine and wastewater treatment system of the volume reduction non-sewered single unit toilet system of FIG. 1 according to various embodiments described herein.

[0025] FIG. 15 illustrates an example method for urine and wastewater treatment according to various embodiments described herein.

[0026] FIG. 16 illustrates an example diagram of a volume reduction solids treatment system of the volume reduction non-sewered single unit toilet system of FIG. 1 according to various embodiments described herein.

[0027] FIGS. 17A and 17B illustrate example back and front views of the volume reduction solids treatment system of FIG. 16 according to various embodiments described herein.

[0028] FIGS. 18A and 18B illustrate an example pasteurizer of the volume reduction solids treatment system of FIG. 16 according to various embodiments described herein.

[0029] FIGS. 19A-19D illustrate an example filter press of the volume reduction solids treatment system of FIG. 16 according to various embodiments described herein. [0030] FIG. 20 illustrates an example of the drying tunnel of the volume reduction solids treatment system of FIG. 16 according to various embodiments described herein.

[0031] FIGS. 21 A and 21B illustrate an example concentrator of the volume reduction solids treatment system of FIG. 16 according to various embodiments described herein.

[0032] FIG. 22 illustrates an example method for volume reduction of solids according to various embodiments described herein.

[0033] FIG. 23 illustrates an example of a two-chamber combustion system according to various embodiments described herein.

[0034] FIG. 24 illustrates an example the combustion section of the two-chamber combustion system of FIG. 23 according to various embodiments described herein.

[0035] FIGS. 25A-25C illustrate an example of the combustion section, disassembled, the two-chamber combustion system of FIG. 23 according to various embodiments described herein.

[0036] FIGS. 26A and 26B illustrate example views of the heat retention insert for the two- chamber combustion system of FIG. 23 according to various embodiments described herein.

[0037] FIGS. 27A and 27B illustrate an example of the chamber grate, tapered flow collar, and the interior collar positioned within the heat retention insert of the two-chamber combustion system of FIG. 23 according to various embodiments described herein.

DETAILED DESCRIPTION

[0038] Sanitation systems are needed for regions of the world where open defecation or lack of improved sanitation is common, which can lead to illness. Traditional sewage and wastewater treatment plants which receive waste from sewers can be expensive to implement and operate. Technologies for multi-unit toilets are being developed to process waste on a large scale. However, there is a need for technology to provide access to safe, affordable sanitation systems that can be deployed in a family home without sewer connections. Holistically, as water scarcity rises across the globe, sanitation systems that reduce reliance on large volumes of water for transport of waste over long distances will become increasingly important, not just in developing countries, but globally.

[0039] To address these deficiencies, various examples of non-sewered single unit toilet systems and methods are disclosed herein. The non-sewered single unit toilet systems are configured to inactivate pathogens from human waste and prepare waste for safe disposal. The non-sewered single unit toilet systems can also recover valuable resources such as clean water. The non-sewered single unit toilet systems can be configured to operate without connection to input water or output sewers. Some example non-sewered single unit toilet systems can be battery based or powered by off-grid renewables. The non-sewered single unit toilet systems can be optimized for low-cost fabrication and low operation costs. The non-sewered single unit toilet systems can promote sustainable sanitation services that operate in poor, urban settings, as well as in developed and developing nations.

[0040] The volume reduction non-sewered single unit toilet system can be configured for stand-alone use. In some examples, the non-sewered single unit toilet system can be configured to provide treated output that meets or exceeds the ISO 30500 standard. The ISO 30500 standard provides a technical standard for non-sewered sanitation systems designed to address basic sanitation needs and promote economic, social, and environmental sustainability through strategies that include minimizing water and energy consumption and converting human excreta to safe output. These sanitation systems are intended to operate without connection to any sewer or drainage network and meet health and environmental safety and regulatory parameters.

[0041] For example, for liquid output, the ISO 30500 reuse standards include chemical oxygen demand (COD) < 50 mg/L, total Nitrogen (N) > 70% reduction, total Phosphorus (P) > 80% reduction, pH: 6.0-9.0, total suspended solids (TSS) < 10, and Escherichia coli ( E . coli ) < 100 per L. In another example, discharge standards include chemical oxygen demand (COD) < 150 mg/L, total Nitrogen (N) > 70% reduction, total Phosphorus (P) > 80% reduction, pH: 6.0-9.0, total suspended solids (TSS) < 30, and E. coli < 100 per L. For example, the E. coli counts in final solid output can be less than 100 per g. Additionally, a gas filter can be configured so that the filtered gas released from the system is ISO 30500 compliant. For example, the non-sewered single unit toilet system can be configured to render the bodily wastes of an adult human into water, CO2, and mineral ash.

[0042] In an example, the non-sewered single unit toilet system can receive unrestricted rates of mixed-content human waste streams and sanitation incidentals. For example, human waste streams can include urine, feces, diarrhea, and the like. For example, sanitation incidentals can include toilet paper, feminine hygiene waste, diapers, other paper products, and the like. In some toilet systems, a portion of sanitation incidentals, including non-organic products such as diapers, can be received and processed separately from the human waste streams. In some examples, the waste streams comprise human feces and urine, menstrual blood, bile, flushing water, anal cleansing water, toilet paper, other bodily fluids and/or solids. Additionally, the waste streams that comprise water, as described herein, can include flush water, rinse water, wash water, fresh water, consumable water, potable water, non-potable water, useable water, and the like.

[0043] The non-sewered single unit toilet system can be configured to separate or process the content of human waste streams separately. Separation of streams can provide more efficient processing than mixed-content human waste streams by dividing the source material into primarily feces, urine, and wastewater streams. Since 100% separation is not practical, a degree of cross contamination between the streams is acceptable for the subsequent downstream treatment approaches. As described herein, the feces stream, containing primarily feces, is also referred to as the “brown stream.” The brown stream is mostly feces, but can also be mixed with other liquid and solid waste. For example, the brown stream can include feces, toilet paper, some urine, and some water. As described herein, the “green stream” can include mostly water, some urine, and some toilet paper, and usually does not include feces. The green stream is mostly liquid with some solids. As described herein, a urine stream, containing primarily urine, is also referred to as the “yellow stream.” For example, a yellow stream can include urine and some water. As described herein, the wastewater stream is also referred to as the “blue stream.” For example, the blue stream can contain primarily wastewater in the form of flush water, anal rinse water, or excess water that is poured into the toilet. In some examples, the blue stream can also include some urine. Stream separation can enable lower cost and more robust treatment processes given the high degree of variability in low volume fecal deposits (recognized as primarily diarrhea), high volume urine deposits, and excessive amounts of flush and anal rinse water, given future water scarcity constraints.

[0044] The non-sewered single unit toilet system can be configured to provide the type of toilet configuration that is acceptable in a particular region of the world. For example, the non- sewered single unit toilet system can be configured to have a main vessel or toilet bowl for collecting human waste that is adapted for either a squat configuration or a pedestal configuration. Additionally, the frontend separation system can be configured to accommodate users that wipe using toilet paper or rinse with water. The frontend separation system can accommodate standing urinators. [0045] In this context, the non-sewered single unit toilet system can be used to receive human waste from urination and/or defecation toilet events, separate the combined human waste into liquids and solids, and reduce the separated liquids and solids to a safe output. In some examples, one or more components of the non-sewered single unit toilet system can include a vent outlet to release air or any gas formed in the components of the system. The gas filter can be configured so that the filtered gas released from the system is ISO 30500 compliant. For example, the non- sewered single unit toilet system can be configured to render the bodily wastes of an adult human into water, CO2, and mineral ash.

[0046] FIG. 1 illustrates an example schematic of a volume reduction non-sewered single unit toilet system 10. The volume reduction non-sewered single unit toilet system 10 can comprise a frontend separation system 100, also referred to as the human waste collection and separation system herein, a buffer tank separation system 200, also referred to as the buffer tank separation and homogenization system herein, a urine and wastewater treatment system 300, and a volume reduction solids treatment system 500. As will be described in further detail, one or more of the frontend separation system 100, the buffer tank separation system 200, the urine and wastewater treatment system 300, and the volume reduction solids treatment system 500 can be considered interconnected to receive input from one or more systems within the volume reduction non- sewered single unit toilet system 10. The volume reduction non-sewered single unit toilet system 10 can also include a control unit 15 comprising a main controller configured to control or operate one or more valves, pumps, motors, sensors, and other devices in the volume reduction non- sewered single unit toilet system 10. In some examples, the volume reduction non-sewered single unit toilet system 10 can also include a two-chamber combustion system 600, which is separate and external to the main volume reduction non-sewered single unit toilet system 10 and configured to transform the pathogen free solids waste to ash.

[0047] The frontend separation system 100, also referred to as the frontend or frontend system herein, can be configured to receive and separate human waste from urination and/or defecation toilet events. For example, the frontend separation system 100 can be configured to be a frontend module to receive human waste, water, and/or toilet paper for the volume reduction non-sewered single unit toilet system 10. Flush water can be received from the urine and wastewater treatment system 300 or from an external source. The frontend separation system 100 can be configured to process mixed human waste and separate the waste into one or more different output streams for further processing and/or treatment. For example, the human waste combined with water and/or toilet paper can be separated into at least two streams: a mostly liquid stream and a mostly solids stream. As described above, the mostly liquid stream, also called the green stream herein, and can contain a proportionally small amount of solids. Mostly liquid can mean less than 5% solid content by volume. The mostly liquid stream, or green stream, can comprise flush water, some urine, some feces, and some toilet paper. As described above, the mostly solids stream, also called the brown stream herein, can contain mostly solids and some liquids. Mostly solids can mean about 1% to about 25% dry solids content by mass. The mostly solids stream, or brown stream, can comprise feces, flush water, urine, and toilet paper. In some examples, a third output stream comprising mostly urine can be diverted prior to separating the combined waste, thus reducing the volume of combined waste to be separated. This mostly urine stream, or yellow stream, can comprise urine and trace amounts of flush water. It is noted that the yellow, green, and brown streams are defined by the composition of human waste as described herein, not by the actual color of the physical stream.

[0048] For example, the frontend separation system 100 can comprise a vessel 102 or 122, a flush tank 104, and solids separator 106 (FIGS. 3A and 3B). The vessel 102 or 122 can receive human waste comprising at least one of: urine and feces. The flush tank 104 can be configured to deliver a volume of flush water to the vessel to form a combined waste with the human waste within the vessel. The solids separator 106 can be configured to evacuate the combined waste from the vessel and separate the combined waste into a separated solids portion and a separated liquid portion and the separated solids portion comprising mostly solids and some fluid and the separated liquid portion comprising mostly fluid with some solids. The frontend separation system 100 will be described in further detail herein.

[0049] The buffer tank separation and homogenization system 200 can receive the one or more output streams from the frontend separation system 100. For example, the buffer tank separation and homogenization system 200 can separately receive the green and brown stream which have been separated by the from the frontend separation system 100. In some examples, a yellow or urine stream can also be received. The buffer tank separation and homogenization system 200 can be a dual chamber tank system for the short-term storage and fractional passive separation of liquid from solid human waste and toilet paper. For example, the buffer tank separation and homogenization system 200 can receive and further separate the solids and liquids of the green stream and brown stream. The buffer tank separation and homogenization system 200 can clarify the green stream by removing solids. For example, the clarified green stream can be part of a liquids output of the buffer tank separation and homogenization system 200 that can be routed to a urine and wastewater treatment system 300 for filtering to produce useable water. The useable water described herein can include non-potable water for use or re-use. The buffer tank separation and homogenization system 200 can remove excess liquid from the brown stream to produce a brown slurry to be delivered to the volume reduction solids treatment system 500 for removal or destruction of pathogens.

[0050] The buffer tank separation and homogenization system 200 can include a mechanism to separate and deliver the solid toilet paper from the green stream to a solids tank and the liquids from the brown stream to a liquids tank. Further, in some examples, the buffer tank separation and homogenization system 200 can receive a yellow stream from the frontend unit that collects and separates a mixed waste. Additionally, recirculation input streams can be received into the buffer tank separation and homogenization system 200. For example, the buffer tank separation and homogenization system 200 can recirculate the contents of the solids and liquids tanks within the system. Also, the buffer tank separation and homogenization system 200 can receive and process streams from the urine and wastewater treatment system 300 and volume reduction solids treatment system 500. For example, a filter concentrate can be received from a urine and wastewater treatment system 300 and a liquid effluent can be received from a volume reduction solids treatment system 500 for further processing.

[0051] The primary output streams from the buffer tank separation and homogenization system 200 are a collected liquids stream and a collected solids slurry, also called a feces slurry herein. The collected solids or “brown” slurry can comprise feces, flush water, toilet paper and urine. A homogenizer, similar in design and operation to a bladed macerator, can be used to transform the collected solids output in the solids tank into a uniform and homogenized slurry for transport to the volume reduction solids treatment system 500. In some examples, the homogenizer can be incorporated into the solids tank design. The brown slurry can be delivered to the volume reduction solids treatment system 500. The liquid effluent or collected liquids from the liquids tank can be pumped from the liquids tank to a urine and wastewater treatment system 300 and can comprise urine, flush water, and trace amounts of toilet paper or other solids. In some examples, the buffer tank system 200 can also receive an overflow from the frontend separation system 100, an ultra-filtration (UF) reject input from the urine and wastewater treatment system 300, and/or a filtrate and/or condensed effluent from the volume reduction solids treatment system 500.

[0052] For example, the buffer tank separation system 200 can comprise a belt separator 204, a liquids collection tank 206, and a solids collection tank 208 (FIG. 8). At least one inlet can comprise a first inlet configured to receive the separated liquid portion of the combined waste and a second inlet configured to receive the separated solids portion of the combined waste from the frontend separation system 100. The belt separator 204 can be positioned to receive an input stream via the at least one inlet onto the belt of the belt separator 204. The input stream can comprise at least one of: the separated solids portion and the separated liquids portion from the frontend separation system 100. The belt separator 204 can be configured to deliver a solids portion of the input stream to the solids collection tank 208 and to deliver the liquids portion of the input stream to the liquids collection tank 206. The liquids collection tank 206 can comprise a liquids outlet configured to release collected liquids. The solids collection tank 208 can comprise a solids outlet configured to release collected solids. In some examples, buffer tank separation system 200 further comprises a homogenizer 210 connected to the solids outlet and configured to receive the collected solids portion and form a uniform and homogenized slurry. The buffer tank separation system 200 will be described in further detail herein.

[0053] The urine and wastewater treatment system 300 can receive the collected liquids output, also referred to as a clarified green stream herein, from the buffer tank separation system 200. The urine and wastewater treatment system 300 can be used to process a liquid stream containing mostly urine, or a green stream of human waste. By separating the green stream prior to input, the urine and wastewater treatment system 300 can operate to process the liquids contained therein. The urine and wastewater treatment system 300 is configured to produce usable water as a liquid output or for flush water in the frontend separation system 100.

[0054] The urine and wastewater treatment system 300 can include a membrane filtration process for the removal of pathogens and chemical contaminants from liquid human waste to produce water suitable for recirculated toilet flushing or safe discharge. The liquid waste, primarily composed of urine, flush water, and trace toilet paper, can pass through a series of filtration stages including an ultra-filtration stage and reverse osmosis stage. Each filtration stage can have an associated reservoir tank and pump component enabling each filtration to operate at the most effective pressure. The rejected concentrate can be recirculated through the filtration stages before diversion to a concentration process for discharge. The permeate can be collected and either recirculated to act as flush water in the toilet system or discharged depending on the system requirements. For example, the liquid permeate of the volume reduction non-sewered single unit toilet system 10 can meet ISO 30500 reuse or discharge standards.

[0055] For example, the urine and wastewater treatment system 300 can receive liquid waste collected in the liquids collection tank 206 of the buffer tank separation system 200. The urine and wastewater treatment system 300 can comprise an air blower 314 and a filtration unit an ultra filtration stage comprising an ultra-filtration filter 304 and a reverse osmosis stage comprising a reverse osmosis filter 312 (FIG. 14). The air blower 314 can be configured to blow air into the liquid waste to reduce the density of the liquid waste and to generate crossflow. The filtration unit can include an ultra-filtration stage and a reverse osmosis stage. The reverse osmosis stage configured to receive a first permeate from the ultra-filtration stage and deliver a usable water. The urine and wastewater treatment separation system 300 will be described in further detail herein.

[0056] The volume reduction solids treatment system 500 can receive input from the buffer tank separation and homogenization system 200 as a feces slurry, also referred to as a brown slurry or brown stream slurry herein, and produce pathogen free solids output. The volume reduction solids treatment system 500 can be configured to process a feces stream or brown stream of human waste. By separating the brown stream prior to input, the volume reduction solids treatment system 500 can operate to process the solids contained therein. Moreover, a brown stream slurry can be obtained by removing excess fluid from the brown stream and homogenizing the contents. The volume reduction solids treatment system 500 can also receive an input from the urine and wastewater treatment system 300 which can be processed and added to feces cakes formed from the feces slurry and output from the volume reduction solids treatment system 500.

[0057] The volume reduction solids treatment system 500 can be configured to produce pathogen free feces cakes suitable either for combustion and reduction to ash or disposal by other means. The feces slurry can pass into a pasteurization heater where it is held at elevated temperatures until pathogen kill is achieved. The treated waste slurry can be transferred at elevated temperatures to a mechanical dewatering filter press. The treated slurry can then be compressed, and the volume reduced solid waste can be ejected from the filter press as a feces cake onto a conveyor for drying in a drying tunnel. The change in volume of the input slurry to the feces cake output can be evaluated in terms of change in water content. For example, the input slurry moisture content can be 96-99% and the output pressed cake moisture content can be 28-84%. This reduction in water content corresponds to at least an 80% reduction in volume. The reduction in volume can be greater than 95%.

[0058] In an example, the removed liquid phase or filtrate can be transported out of the volume reduction solids treatment system 500 for treatment in the buffer tank system 200. In an example, the conveyor can transport the feces cakes to the disposal bin over a period of 8-10 hours. In an example, the conveyor can be housed in a drying tunnel. The drying tunnel being a contained air duct system to enable forced air to be propelled over the feces cakes to provide evaporative drying of the feces cakes during transport. The final cakes can have 4-10% moisture content and be deposited in a removable bin for subsequent disposal. In an example, the feces cakes can be reduced to ash in an external two-chamber combustion system 600.

[0059] For example, the volume reduction solids treatment system 500 can receive a feces slurry comprising the solids waste collected in the solids collection tank 208 of the buffer tank separation system 200. The solids waste treatment system 500 can comprise a pasteurizer 502, a mechanical dewatering press 504, and a drying tunnel 506 (FIG. 16). The pasteurizer 502 can receive a slurry batch and heat the slurry batch at an elevated temperature for a time period to produce a pathogen free slurry. The mechanical dewatering press 504 can compress the pathogen free slurry to separate a liquid phase from a volume reduced solid waste, where the volume reduced solid waste is formed into a feces cake. The drying tunnel 506 can comprise a conveyor housed and an air duct system, where the air duct system configured to propel forced air over the feces cake. In some examples, the volume reduction solids treatment system 500 can also include a concentrator 512 configured to receive a filtered concentrate from the buffer tank separation system 300 and reduce the filtered concentrate by heating and evaporation forming a condensed effluent. In some examples, the condensed effluent can be delivered to the drying tunnel for further evaporation and output with the feces cakes. In another example, a portion of the condensed effluent can be delivered to the buffer tank separation system 300. The volume reduction solids treatment system 500 will be described in further detail herein.

[0060] In some examples, the volume reduction non-sewered single unit toilet system 10 can also include a two-chamber combustion system 600, which is separate and external to the main volume reduction non-sewered single unit toilet system 10 and configured to transform the feces cakes to ash. The two-chamber combustion system 600 can comprise first and second chambers with an effective air flow for the evaporative drying and combustion of dried, volume reduced feces cakes, and reduction to ash using biofuel sources to initiate combustion. For example, the biofuel sources can be placed in a first chamber and the dried or partially dried feces cakes can be placed in a second chamber. The biofuel sources can include paper, twigs, wood, and the like. For example, dried or partially dried feces cakes can be produced by the volume reduction solids treatment system 500 of the volume reduction non-sewered single unit toilet system 10, then be transported, by the user, to the two-chamber combustion system 600 to reduce a feces output to inert ash. In some examples, the feces cakes can be transported using a defined disposal bin to the two-chamber combustion system 600. The two-chamber combustion system 600 is configured to be located on in an exterior location, outside of a house, ideally attached to an external wall for stability. The disposal bin can be designed to selectively interface with the two-chamber combustion system 600, both to enable clean transport of the feces cakes to the two-chamber combustion system 600 and to prevent the introduction of other foreign material for burning. In some examples, feces cakes can be transported by other means to the two-chamber combustion system 600 and the disposal bin is not necessary.

[0061] The volume reduction non-sewered single unit toilet system 10 can also include control unit 15 can comprise a main controller configured to control or operate one or more valves, pumps, motors, sensors, and other devices in the volume reduction non-sewered single unit toilet system 10. As described in further detail below, the volume reduction non-sewered single unit toilet system 10 can also comprise individual controllers for each of the frontend separation system 100, the buffer tank system 200, the urine and wastewater treatment system 300, and the volume reduction solids treatment system 500. The main controller of control unit 15 and other individual controllers can be embodied in the form of hardware, firmware, software executable by hardware, or as any combination thereof, including at least one processor or processing circuit and a memory device. Although the other controllers are shown schematically as separate controllers herein, the controllers can also be configured to operate the individual systems or embodied as part of the control unit 15. For example, controller 115 in FIGS. 3A and 3B, controller 215 in FIG. 8, controller 315 in FIG. 14, and controller 515 in FIG. 16 can be embodied as part of control unit 15. The two-chamber combustion system 600 is operated manually and not controlled by the control unit 15.

[0062] FIG. 2 shows an example method for separation of human waste and removal of pathogens using the volume reduction non-sewered single unit toilet system 10 of FIG. 1 as described herein. The example method for separation of human waste and removal of pathogens using the volume reduction non-sewered single unit toilet system 10 can include additional steps as related to the method and operation of the frontend separation system 100, the buffer tank separation system 200, the urine and wastewater treatment system 300, the volume reduction solids treatment system 500, and the two-chamber combustion system 600 as shown and described herein.

[0063] At box 1002, receive a human waste into a frontend separation system 100. For example, the human waste can be received into a vessel 102 or 122 of a frontend separation system 100. In some examples, the human waste can be received by other means. The human waste can be at least one of urine and feces. In some examples, the human waste can be combined with at least one of water and toilet paper. The water can be flush water, rinse water, wash water, fresh water, consumable water, potable water, non-potable water, useable water, or other water that is compatible for use with the volume reduction non-sewered single unit toilet system. In some examples, suitable cleaning compositions, such as a cleaning fluid or powder, can be deposited and combined with water in the vessel to clean the vessel then flushed can also be considered human waste herein. The frontend separation system 100 can receive flush water for to be used in the vessel from the urine and wastewater system 300. In some examples, an overflow from the frontend separation system 100 can be directed to the buffer tank separation system 200.

[0064] At box 1004, separate the human waste into at least one of a mostly liquid stream and a mostly solids stream. The human waste received into the vessel 102 or 122 of the frontend separation system 100 can be combined with at least a volume of water to form a combined waste. The combined waste can be evacuated from the vessel 102 or 122 into a frontend solids separator 106. A liquids portion of the combined waste can be separated through a separating filter 134 to collect the liquids in the liquids containment portion 162. The solids portion of the combined waste can be retained within the separating filter 134 and collected in the solid containment portion 160 of the frontend solids separator 106. Additional features of the frontend separation system 100 and operation thereof are shown in FIGS. 3A-7 and described herein. [0065] At box 1006, deliver the mostly liquid stream from the frontend separation system 100 to a buffer tank separation system 200. For example, the mostly liquid stream can be delivered to a liquids input of the buffer tank separation system 200. The mostly liquid stream can be less than 5% solid content by volume. In some examples, when the vessel 122 comprising a urine diverter 124 is used, an additional separate a urine stream from the human waste can be delivered from a urine tank 126 to the buffer tank separation system 200 or some other system for further processing.

[0066] At box 1008, separate at least some of the solids from the mostly liquid stream. The mostly liquid stream can be received via a first inlet onto a belt separator 204 and at least some of the solids separated from the mostly liquid stream. At box 1010, deposit the solids separated from the mostly liquid stream into the solids collection tank 208 and deposit the remaining portion of the mostly liquid stream into a liquids collection tank 206 for short-term storage and passive separation of liquid from remaining solid waste received into the liquids collection tank. In some examples, when the vessel 122 is used, the urine stream delivered from the urine tank 126 can be received via an alternate inlet onto the belt separator to remove any trace solids and direct the urine to the liquids tank. The urine stream can comprise mostly urine, some water, and trace solids.

[0067] At box 1012, deliver the mostly solids stream from the frontend separation system to the buffer tank separation system. For example, the mostly solids stream can be delivered to a solids input of the buffer tank separation system. The mostly solids stream is about 1% to about 25% solid content by volume.

[0068] At box 1014, separate most of the solids from the mostly solids stream. For example, the mostly solids stream can be received via a second inlet onto the belt separator and most of the solids separated from the mostly solids stream. At box 1016, deposit the solids separated from the mostly solids stream into the solids collection tank and deposit the remaining portion of the mostly solids stream into the liquids collection tank for short-term storage and passive separation of liquid from remaining solid waste received into the liquids collection tank. Additional features of the buffer tank separation system 200 and operation thereof are shown in FIGS. 8-13D and described herein.

[0069] At box 1018, separate pathogens from a liquid waste received from a volume of collected liquids separated within the liquids collection tank in a urine and wastewater treatment system. In some examples, solids in the remaining portion of the mostly liquid stream can form a sludge by sedimentation at the bottom of the liquids collection tank 206. In some examples, the sludge can be delivered to the belt separator 204 via an alternate inlet and solids removed from the sludge and delivered to the solids tank 208. Additional features of the urine and wastewater treatment system 300 and operation thereof are shown in FIGS. 14-15 and described herein.

[0070] For example, separating pathogens from a liquid waste received from a volume of collected liquids separated within the liquids collection tank in a urine and wastewater treatment system can comprise: receiving a liquid waste comprising the volume of collected liquids separated within the liquids collection tank; blowing air into the liquid waste to reduce the density of the liquid waste and to generate crossflow; filtering the liquid waste in an ultra-filtration stage to separate a first permeate and a first concentrate; discharging the first concentrate to the buffer tank system; filtering the first permeate in a reverse osmosis stage to separate a second permeate and a second concentrate; recirculating the second concentrate to filter in reverse osmosis stage; and discharging the second permeate as useable water.

[0071] At box 1020, deliver a volume of collected solids settled within the solids collection tank to a homogenizer to form a feces slurry. In some examples, a portion of the contents of the solids collection tank 208 can be delivered to the belt separator 204 via an alternate inlet and solids removed from the portion and delivered to the solids tank 208 and liquids delivered to the liquids collection tank 206.

[0072] At box 1022, inactivate pathogens from the feces slurry in a volume reduction solids treatment system and forming feces cakes by removing moisture from the pathogen free slurry. Additional features of the volume reduction solids treatment system 500 and operation thereof are shown in FIGS. 16-22 and described herein. In some examples, the feces cakes can be reduced to ash within an external two-chamber combustion system 600. Additional features of the two- chamber combustion system 600 and operation thereof are shown in FIGS. 23-27B and described herein.

[0073] For example, inactivating pathogens from the feces slurry in a volume reduction solids treatment system and forming feces cakes by removing moisture from the pathogen free slurry can comprise: receiving, into a pasteurizer, a slurry batch comprising the feces slurry; heating the slurry batch at an elevated temperature for a time period, the time period sufficient to kill pathogens producing a pathogen reduced slurry; transferring the pathogen reduced slurry to a mechanical dewatering press; compressing the pathogen reduced slurry in the mechanical dewatering press to separate a liquid phase from a volume reduced solid waste; removing the liquid phase; forming a feces cake from the volume reduced solid waste; ejecting the volume reduced solid waste onto a conveyor; and removing moisture from the feces cake in a drying tunnel.

[0074] As can be understood, the example method can be carried out in the order recited or in any other order that is logically possible. The method can omit steps or include additional steps. For example, the method can include additional steps as described in FIGS. 7, 12, 15, and 22 as described herein.

[0075] In the following discussion, a general description of the frontend separation system 100, the buffer tank separation system 200, the urine and wastewater treatment system 300, the volume reduction solids treatment system 500, and the two-chamber combustion system 600 and their components is provided, including a discussion of the operation of the same. Non-limiting examples the volume reduction non-sewered single unit toilet system 10 and methods are discussed.

[0076] FRONTEND SEPARATION SYSTEM

[0077] In FIGS. 3A-6, the frontend separation system 100 of the volume reduction non- sewered single unit toilet system 10 is shown in greater detail. The frontend separation system 100 can process mixed human waste and separate the waste into at least two different output streams for further processing and/or treatment. The human waste combined with water and/or toilet paper can be separated into at least two streams: a mostly liquid stream and a mostly solids stream. As described above, the mostly liquid stream, also called the green stream herein, and can contain a proportionally small amount of solids. The mostly liquid stream, or green stream, can comprise flush water, some urine, some feces, and some toilet paper. As described above, the mostly solids stream, also called the brown stream herein, can contain mostly solids and some liquid. The mostly solids stream, or brown stream, can comprise feces, flush water, urine, and toilet paper. In some examples, a third output stream comprising mostly urine can be diverted prior to separating the combined waste, thus reducing the volume of combined waste to be separated. This mostly urine stream, or yellow stream, can comprise urine and trace amounts of flush water. It is noted that the yellow, green, and brown streams are defined by the composition of human waste as described herein, not by the actual color of the physical stream.

[0078] As illustrated in FIG. 3 A, the frontend separation system 100 can comprise a main vessel 102, a flush tank 104, and a frontend solids separator 106. The frontend separation system 100 can also include a user interface panel 108, a controller 115, and a vacuum pump 112. The main vessel 102 can be a toilet bowl configured to receive human waste, such as urine and feces, as well as toilet paper. After a urination and/or defecation event, a volume of flush water, received from the flush tank 104, can be added to the main vessel 102 forming a combined waste within the vessel. The combined waste can be evacuated through a main outlet 114 of the main vessel 102 into the solids separator 106. The combined waste received into the solids separator 106 can be separated into a liquid portion comprising mostly liquids with some solids and a solids portion comprising mostly solids and some liquids. For example, in FIG. 3A, two outputs of the solids separator 106 are labeled as the green stream, which is the liquid portion, and the brown stream, which is the solids portion.

[0079] The frontend separation system 100 is configured to receive human waste from a user into a main vessel 102. The main vessel 102 can be configured based on a regional preference and/or customs. In some regions of the world, users are accustomed to a squat configuration toilet. In some regions of the world, users are accustomed to a pedestal or sitting configuration toilet. The main vessel 102 can be a toilet bowl configured for either a squat or pedestal configuration. Similarly, the while the examples of combined waste herein include feces, urine, toilet paper, and/or flush water, in some regions of the world, it may not be customary to use toilet paper. For users that do not use toilet paper, frontend separation system 100 and the main vessel 102 can be adapted for a rinse configuration. In a rinse configuration, the excess rinse water can also be accommodated and can be considered as added to the combined waste instead of or in addition to the flush water.

[0080] The flush tank 104 can be configured to deliver a volume of flush water to the main vessel 102. In some examples, the volume of flush water is a predetermined amount regardless of the human waste event. In some examples, the predetermined amount of flush water is based on whether the human waste received is due to a urination event or a defecation event. The flush tank 104 can be configured to receive and store water from an external system or recirculated source for use as flush water. In one example, the water for the flush tank 104 can be received from another system or module of a toilet system that interconnects with the frontend separation system 100. For example, the water for the flush tank 104 can be received from the urine and wastewater treatment system 300. In another example, the water for the flush tank 104 can be received from a municipal water supply or other external water supply. The flush tank 104 can also be configured with an overflow outlet to divert excess water to the buffer tank separation system 200. The human waste collection and separation system can be configured with an overflow output from a flush tank 104.

[0081] The frontend separation system 100 can also include a controller 115. For example, the controller 115 can include a microprocessor and memory and be configured to control or operate one or more elements of the frontend separation system 100. The controller 115 can be CE compliant. The controller 115 can be configured initiate a flush sequence and to control or operate additional elements for the frontend separation system 100. For example, the controller 115 can operate the vacuum pump 112, main valve 116, and additional components not shown. For example, the frontend separation system 100 can also comprise valves, pumps, motors, sensors, and the like (not shown). The controller 115 can be configured to control or operate one or more valves, pumps, motors, and sensors based on an indication that user input has been received in the main vessel. For example, a sensor and/or input via the user interface panel 108 can control the operation of the vacuum pump 112 or other means to evacuate the main vessel 102. The waste from the main vessel 102 can be routed to the solids separator 106 by actuating the main valve 116. Additionally, the controller 115 can be configured to control the release of a separated liquids portion and/or separated solids portion in the vacuum tank.

[0082] As shown in FIG. 3 A, a user interface panel 108 can be configured to initiate the release of a volume of flush water from the flush tank 104 into the main vessel 102. In some examples, the user interface panel 108 can include buttons or other selector options for the user to select a urination or defecation waste event to flush the toilet. For example, the selector options may include buttons, levers, switches, knobs, digital interfaces, and the like. For example, if the user deposits toilet paper during the urination event, the user can select a small flush button on the user interface panel 108 to release a first predetermined volume of water to and from the flush tank 104 to wash any residual urine and/or toilet paper and evacuate the contents of main vessel 102 to the frontend solids separator 106. Similarly, for a defecation event, the user can select a flush button on the user interface panel 108 to release a second predetermined volume of water to and from the flush tank 104 to wash the mixed waste contents and evacuate the main vessel 102 to the frontend solids separator 106. For example, the first predetermined volume of water can be a smaller amount for a urination event compared to a larger amount of the second predetermined volume of water for a defecation event. [0083] In an example, the user interface panel 108 can have color coded buttons for identification by the user, but color is not necessary. For example, the buttons could include symbols and/or words. Further, a simplified panel may only include two buttons for a urination event and a defecation event. In a simplified example, the size of the button may indicate the type of event. For example, a smaller button may indicate a urination event to release a first predetermined volume of water, and a larger button may indicate a defecation event to release a second predetermined volume of water, which is a larger volume of water. The user interface panel 108 is not limited to the example configurations provided, as the buttons in the panel are configured to activate a signal to the controller 115 to operate a flush sequence related to the waste event. For example, the user can select a flush button on the user interface panel 108 to select the type of waste event, such as a urination or defecation event. For a waste event that includes at least toilet paper, the contents of the main vessel 102 can be routed to the solids separator 106. For example, for a human waste event, the event flush button is pressed, flush water is introduced to the main vessel 102 from the flush tank 104 to wash a mixture of residual urine, residual feces, and/or toilet paper to the bottom of the main vessel 102, which is closed off by a main valve 116, which is a two-way valve. At this time, a weak vacuum can be generated in the solids separator 106 by activation of the vacuum pump 112. Once a predetermined vacuum pressure is achieved, the main valve 116 can be opened and the waste transported to into the solids separator 106.

[0084] In another example, the frontend separation system 100 can comprise at least one sensor configured to detect a waste event and send a signal to the controller 115 to control the flush operation to release water from the flush tank 104. In an example with at least one sensor, the user interface panel 108 can be optional, omitted, or serve as a backup secondary to the sensors. In some examples, the sensors can detect a urination or defecation event and release a first or a second predetermined volume of water accordingly.

[0085] In another example system, as shown in FIG. 3B, the alternate main vessel 122 can comprise a urine diverter 124 to provide an additional output stream comprising urine from the frontend separation system 101 (system 101). System 101 is substantially the same as frontend separation system 100 with a substitution of alternate main vessel 122 comprising a urine diverter 124, as well additional features to route the diverted urine stream, shown as the yellow stream in FIG. 3B. One example of a main vessel including a urine diverter is disclosed for example in PCT application No. PCT/AT2019/060064. The urine diverter can be shaped within the vessel and configured such that surface tension and cohesive effects allow the bypass portion of the liquid waste to follow the contour of the vessel to a bypass liquids outlet. With this optional feature of an alternate main vessel 122 comprising a urine diverter 124, the alternate main vessel 122 can be configured in either a squat or pedestal configuration and can be adapted for a rinse configuration, as specified for different regions of the world. The urine diverter 124 can be incorporated into the geometry of the toilet bowl design and configured to capture the urine in a passive manner. For example, a urination event or waste event comprising urine, the urine is in a liquid form, thus there is no need to separate solids. When using the alternate main vessel 122 comprising a urine diverter 124, the urine can be separated from without the use of water via a urine diverter 124.

[0086] In some examples, the urine stream output shown as the yellow stream in FIG. 3B can be temporarily stored in a urine tank 126 or routed to join the liquid output stream from the solids separator 106 or routed treatment in another module or system. For example, a urine stream from the urine tank 126 can be directed to an auxiliary inlet of the buffer tank separation and homogenization system 200. In some examples, the yellow and green streams can be transported separately to other systems or treatment modules, or combined for transport, depending on the type of toilet or treatment system to which the frontend separation system 101 is connected. For example, if a treatment system can utilize or output the separated urine, the yellow and green streams can remain separate. In another example, the yellow and green streams can be combined and processed as a liquid waste stream.

[0087] As shown in FIG. 3B, the remaining features of system 101 are substantially the same as shown in frontend separation system 100 of FIG. 3A. For some urination events, at least a portion of the urine can be diverted or routed separately. As described with respect to frontend separation system 100, the user input received or remaining in the alternate main vessel 122 is combined with water with a flush event to form a combined waste that can be routed to the solids separator 106 by actuating the main valve 116. For example, a waste event that includes at least toilet paper, the mixed waste contents of the alternate main vessel 122 can be routed to the solids separator 106 by generating a weak vacuum in the solids separator 106 by activation of the vacuum pump 112. Once a predetermined vacuum pressure is achieved, the main valve 116 can be opened and the waste transported to into the solids separator 106. [0088] The controller 115 can be configured to control or operate additional elements for the system 101. For example, the system 101 can also comprise valves, pumps, motors, sensors, and the like (not shown) to control and facilitate the operation of the system, including transporting urine from the urine tank 126. In some examples, a urine tank 126 can be included in the frontend separation system 101 having the alternate main vessel 122. A sensor can be positioned at the urine tank 126 to monitor the level of liquid in the urine tank. In some examples, a pump can be provided to facilitate the movement of the yellow stream from the urine tank 126 to an outlet of the frontend separation system 101.

[0089] Referring to FIGS. 4 and 5 an example of a frontend solids separator 106 is illustrated. As shown in FIG. 4, an example solids separator 106 includes a vacuum tank 130 having an inlet 132, a separating filter 134, a solids outlet 136, and a liquids outlet 138. The vacuum tank 130 can include a top portion 140, a base 142, and a cylindrical wall 144. The solids separator 106 can also include a first valve 146 and a first actuator 148 for the solids outlet 136 and a second valve 150 and a second actuator 152 for the liquids outlet 138. The first valve 146 and second valve 150 can be two-way valves.

[0090] In FIG. 5, a cross section of the vacuum tank 130 is shown. The vacuum tank 130 comprises an inlet chamber 156 formed within the vacuum tank 130 at the top portion 140. The inlet chamber 156 comprising the inlet 132 and a chamber outlet 158. A solids containment portion 160 is formed in the base 142 of the vacuum tank 130 and positioned centrally within the vacuum tank 130. The solids containment portion 160 includes the solids outlet 136. The solids containment portion 160 is configured to hold a separated solids volume of the combined waste that is controlled by the geometry. For example, the solids containment portion 160 can have a conical shape, with a first diameter (d _si ) substantially equal to the diameter of the separating filter 134 and a second diameter (d _S 2) at the chamber outlet 158. For example, the diameters of 160 can vary and conical angle can vary between 0 degrees and 90 degrees to a control the volume of the separated solids in 160. A liquids containment portion 162 is formed in the base 142 of the vacuum tank 130 and contained within the vacuum tank 130 surrounding the solids containment portion 160. The liquids containment portion 162 includes a liquids outlet 138. The liquids containment portion 162 is configured to hold a separated liquid portion of the combined waste portion. The separating filter 134 having a cylindrical tubular shape and extending from the chamber outlet 158 to the solids containment portion 160. The separating filter 134 forming a central separation volume 164 within the vacuum tank 130.

[0091] The inlet chamber 156 is configured to receive the combined waste via the inlet 132 and to direct the combined waste to the central separation volume 164. The liquid portion of the combined waste is allowed to flow through the separating filter 134 to an outer portion 166 surrounding the central separation volume 164 and collects in the liquids containment portion 162 of the base 142. The solids portion of the combined waste is contained within the central separation volume 164 and collected in the solids containment portion 160 of the base 142. The solids containment portion 160 can have funnel or conical shape to direct the solids portion of the combined waste to the solids outlet 136. As will be further described, the solids portion collected in the solids containment portion 160 can be released via solids outlet 136 by actuating the first valve 146. The base 142 of the vacuum tank 130 has an inclined base within the liquids containment portion 162 such that a flow of the liquid portion of the combined waste collected in the liquids containment portion 162 is directed to the liquids outlet 138 by gravity. The liquid portion collected in the liquids containment portion 162 can be released via liquids outlet 138 by actuating the second valve 150.

[0092] The separating filter 134 can comprise profile wires 168 mounted on supports 170 and aligned to form slots 172 (FIG. 6) configured to retain solids in the central separation volume 164 and allow liquids to pass through to the outer portion 166 of the vacuum tank 130. The profile wires 169 can be rods formed with a specified profile cross section. In an example, each profile wire can have cross section with a wedge shape. In other examples, the profile wire can have a circular, rectangular, triangular, or other specified shape. The separating filter 134 can be configured with the profile wires 168 spaced with to for slots with a predetermined minimum width (wi) on at least one side. The size and shape of the slots may vary based on the configuration. For example, the profile wires 168 can be arranged to form slots 172 between the profile wires 168, such that if the arrangement is flat, the slots have a predetermined minimum width (wi) on at least one side of the arrangement.

[0093] In the example shown in FIGS. 4 and 5, the supports 170 are oriented in a direction substantially parallel to the central axis (X) of the vacuum tank 130, and the profile wires 168 of the separating filter 134 are oriented in a substantially horizontal direction, such that the slots 172 between the profile wires 168 are oriented in a direction substantially perpendicular to the central axis (X) of the vacuum tank 130. In another example (not shown), the profile wires 168 of the separating filter 134 are oriented in a direction substantially parallel to the central axis (X) of the vacuum tank 130, such that the slots between the profile wires 168 are oriented in a direction substantially parallel to the central axis of the vacuum tank 130.

[0094] In FIG. 6, a portion of the separating filter 134 is shown to illustrate the liquid separation of the combined waste in greater detail. In one example, the separating filter 134 can be a wedge wire filter, although the design can be implemented and relied upon in other types and configurations of metal or wire filters. In this example, the separating filter 134 comprises a plurality of profile wires 168, each of the profile wires having a wedge shape or triangular cross- section. The plurality of profile wires 168 can be arranged at a regular interval to form a plurality of grooves extending from slits between the profile wires at an inner circumference of the cylindrical tubular shape of the separating filter 134 to wider openings at an outer circumference of the cylindrical tubular shape. For example, the plurality of profile wires 168 can be wedge wires and arranged such that the separating filter 134 has V-shaped grooves extending from slots with a predetermined minimum width (wi) between the wedge wires at an inner circumference of the cylindrical tubular shape at the central separation volume 164 to wider openings (w2) at an outer circumference of the cylindrical tubular shape at the outer portion 166. The shape of the profile wires allowing the liquid to pass while the solids are contained within the central separation volume 164 and directed to the solids containment portion 160 in the base 142 of the vacuum tank 130. For example, the controller 115 can also actuate pumps, motors, and valves to control of the vacuum tank 130. The controller 115 can actuate the vacuum pump 112 to evacuate the combined waste from the main vessel 102 or alternate main vessel 122 into the inlet chamber 156 via the inlet 132. The inlet 132 and inlet chamber 156 are configured such that when the combined waste stream enters the inlet chamber 156, the velocity of combined waste stream is slowed by the geometry of the inlet chamber 156 such that the combined waste stream is guided in a spiral to the central separation volume 164 of the vacuum tank 130. The fluids can pass through the separating filter 134 and collect in the liquids containment portion 162 of the base 142.

[0095] For a urination event, the proportionally small amount of solids can collect in the solids containment portion 160; however, the solids can remain collected until a subsequent event with additional solids. For example, if a urination event is determined by user selection or a sensor, the controller 115 can actuate the second valve 150 to release the collected liquids via the liquids outlet 138.

[0096] For a defecation event, where a solids portion is collected in the solids containment portion 160 in the base 142 of the vacuum tank 130, an overpressure can be applied to the vacuum tank 130 such that some remaining liquids within the separation volume are forced under pressure through the separating filter to collect in the liquids containment portion 162 of the base 142. The same vacuum pump 112 can be reversed for overpressure or separate pumps can be used to pressurize the content of the vacuum tank 130. The solids portion of the combined waste collected in the solids containment portion 160 can be released via the solids outlet 136 after a pressure is applied to the vacuum tank. A first actuator 148 can be configured to operate a first valve at the solids outlet 136 and a second actuator 152 can be configured to operate a second valve 150 at the liquids outlet 138. The controller can be configured to open the first valve 146 when an overpressure is applied to the vacuum tank 130, releasing the solids portion of the combined waste collected in the solids containment portion 160. The second valve 150 can be actuated after the first valve 146, releasing the liquid portion of the combined waste collected in the liquids containment portion 162. The liquid portion of the combined waste collected in the liquids containment portion 162 can be released via the liquids outlet 138 by flow due to gravity after opening the second valve 150.

[0097] The solids separator 106 is configured with a first valve 146 at the solids outlet 136 that is actuated by a motor. In another example, the first valve 146 can be actuated by an overpressure. For example, the first valve 146 can be a ball valve. As the contents of the vacuum tank are pressurized, the first valve can be opened to direct the solids stream for treatment of the feces and other solids in one or more modules of volume reduction non-sewered single unit toilet system 10. For example, the solids stream output can be delivered as the input into a volume reduction solids treatment system 500. After the pressurization of the vacuum tank and release of the solids portion, the liquid portion can be released by opening the two-way valve. The liquid portions are allowed to passively drain from the liquid containment portion. The base of the liquid containment portion having an incline to direct the liquid to the liquids outlet 138. The liquid stream released from the liquids outlet 138 can be directed for treatment in one or more modules of volume reduction non-sewered single unit toilet system 10. For example, the liquid stream output can be delivered as the input into the urine and wastewater treatment system 300. For example, the liquid stream can be directed to a buffer tank separation system 200 and/or the urine and wastewater treatment system 300. In an example, the liquid portion separated from the combined waste comprises less than 5% dry solids content, the solid content comprising feces and toilet paper. In an example, the solids portion separated from the combined waste comprises about l%-25% dry solids content, the solid content comprising feces and toilet paper.

[0098] The frontend can also include a touchless human machine interface configured to communicate the status of the toilet system to the user. For example, the human machine interface can be integrated into the user interface pane and can indicate that the toilet system is ready to use, requires maintenance, is shutdown, etc. The frontend separation system can be connected to a power source and, in some examples, can also include a backup battery in the case of intermittent power or temporary power loss. In some examples, the frontend separation system 100 or complete toilet system 10 can be powered by a battery or off-grid energy systems.

[0099] FIG. 7 shows an example method for collection and separation of human waste using the frontend separation system 100 of FIG. 3 A as described herein. At box 1102, receive a human waste into a vessel. The human waste comprises at least one of a liquid waste and a solids waste. The liquid waste comprises at least one of: urine and water. The solids waste comprises at least one of: feces and toilet incidentals, such as toilet paper.

[00100] In some examples, when the vessel includes a urine diverter 124, such as system 101 as shown in FIG. 3B, the method can also include diverting a bypass portion of the urine via a urine diverter formed in the vessel. For example, the bypass liquids outlet can be connected to a urine tank 126 to hold the liquid containing mostly urine before releasing a yellow stream for further treatment. For example, for a urination event, the liquid waste can comprise mostly urine and some water and be diverted from the main vessel outlet 114 via the urine diverter 126 to a yellow stream outlet.

[00101] At box 1104, receive a volume of flush water for a human waste event sufficient to wash any residual urine, residual feces, and toilet paper to the main outlet of the main vessel. In some examples, a predetermined volume of water is used for any human waste event. In some examples, a first predetermined volume can be used for a urination event and a second predetermined volume can be used for a defecation event. For example, the first predetermined volume can be considered small, relative to the volume of water needed for a defecation event. [00102] At box 1106, evacuate the combined waste, including the flush water, via the main outlet of the main vessel. A vacuum pump can be used to form a weak vacuum to transport the combined waste to a vacuum tank of the solids separator.

[00103] At box 1108, receive the combined waste into the inlet portion of a vacuum tank of a solids separator. The inlet portion can be shaped to decelerate and direct the combined waste into a separation volume within the vacuum tank. The inlet to the solids separator can be positioned to receive the combined waste tangentially and direct the combined waste along a circumferential interior wall of the inlet chamber to decelerate and damper the input. For example, the inlet can be positioned off center, such that the combined waste stream received flows in along the interior wall inlet chamber, and in a circular motion through the inlet chamber, where the chamber is shaped to guide the combined waste stream to the chamber outlet. For example, the inlet is off set from the center and formed such that the input stream is guided in a spiral.

[00104] At box 1110, separate a liquids portion of the combined waste through the separating filter to collect the liquids portion in a liquid containment portion of the base. The base can have a solids containment portion formed in the base of the vacuum tank and positioned centrally within the vacuum tank and a liquid containment portion formed in the base and surrounding the solids containment portion. As the combined waste stream is received into the separation volume within the separating filter, some of the liquid having lateral directional motion will pass through the separating filter. The liquid of combined waste received into the separation volume can also be directed to flow through the separating filter by gravity.

[00105] At box 1112, collect the solids portion of the combined waste in the solids containment portion of the base. The solids containment volume can be configured to hold a separated solids portion of the combined waste as the liquid portions pass through to a volume between the separating filter and the vacuum tank wall. The solids portion of the combined waste can remain within the separating filter as the combined waste settles by gravity. The solids containment portion can have a funnel shape to contain and direct the solids to the solids outlet 136, while allowing excess liquid to collect in the liquid containment portion.

[00106] At box 1114, release a liquid portion of the combined waste that has collected in the liquid containment portion formed in the base of the vacuum tank. The solids separator configured with a two-way valve at the liquids outlet 138 can be operated by an actuator liquid portion can be released by opening the two-way valve. The liquid portion is allowed to passively drain from the liquid containment portion. The base of the liquid containment portion can have an incline to direct the liquid to the liquids outlet 138. The liquid stream released from the liquids outlet 138 can be directed for treatment in the buffer separation system 200. For example, the liquid stream output can be delivered as the input the buffer separation system 200.

[00107] At box 1116, release the solids portion of the combined waste that has collected in the solids containment portion via the solids outlet 136. The solids can be released with overpressure or with gravity only. When the evacuation of the vacuum tank is done by overpressure, the liquid needs to be drained before overpressure is applied. An overpressure can be applied to the vacuum tank such that some remaining liquids within the separation volume are forced with air through the separating filter to collect in the liquid containment portion of the base. The solids separator is configured with a two-way valve at the solids outlet 136 that is actuated by a motor. As the contents of the vacuum tank are pressurized, the two-way valve can be opened to direct the solids stream for treatment in the volume reduction solids treatment system 500. For example, the solids stream output can be delivered as the input into the volume reduction solids treatment system 500.

[00108] BUFFER TANK SEPARATION AND HOMOGENIZATION SYSTEM

[00109] Next, in FIGS. 8-13D the buffer tank separation and homogenization system 200 of the volume reduction non-sewered single unit toilet system 10 is shown in greater detail. The buffer tank separation and homogenization system 200 can be a dual chamber tank system for the short-term storage and fractional passive separation of liquid from solid human waste and toilet paper. The buffer tank separation and homogenization system 200 can be connected to a homogenization component that macerates the solid waste to a uniform particle size and transports the slurry to the volume reduction solids treatment system 500. The buffer tank separation and homogenization system 200 can receive at least one input and produce at least two outputs that can be delivered separately for further treatment. For example, at least one input stream can be received into the buffer tank separation and homogenization system 200 from a frontend unit that collects and separates a mixed waste. In an example, the frontend separation system 100 can deliver a green stream and a brown stream. In some examples, the frontend separation system 100 can deliver a green stream, a brown stream, and a yellow stream. A green stream, comprising primarily urine, flush water and toilet paper can be delivered to a liquids tank or “green tank” and a brown stream, comprising a mixture of feces, urine, flush water, and toilet paper can be delivered to a solids tank or “brown tank.” It is noted that the yellow, green, and brown streams are defined by the composition of human waste, as described herein, not by the actual color of the physical stream. Similarly, the liquids tank and the solids tank can contain both liquids and solids. The output from the liquids tank can be delivered to the urine and wastewater system 300 for removal or destruction of pathogens or contaminants to produce usable water. The output from the solids tank can be delivered to the volume reduction solids treatment system 500 for removal or destruction of pathogens or contaminants to produce inert material output.

[00110] The buffer tank separation and homogenization system 200 can include a mechanism to separate and deliver the solid toilet paper from the green stream to the solids tank and the liquids from the brown stream to the liquids tank. Further, in some examples, the buffer tank separation and homogenization system 200 can receive a yellow stream from the frontend separation system 100. Additionally, recirculation input streams can be received into the buffer tank separation and homogenization system 200. For example, a filter concentrate can be received from the urine and wastewater treatment system 300 and a liquid effluent can be received from the volume reduction solids treatment system 500 for further processing.

[00111] The primary output streams from the buffer tank separation and homogenization system 200 are a collected liquids stream and a collected solids slurry. The collected solids or “brown” slurry or feces slurry can comprise feces, flush water, toilet paper and urine. A homogenizer, similar in design and operation to a bladed macerator, can be used to transform the collected solids output in the solids tank into a uniform and homogenized slurry for transport to the treatment modules. In some examples, the homogenizer can be incorporated into the solids tank design. The brown slurry can be delivered to the volume reduction solids treatment system 500. The liquid effluent or collected liquids from the liquids tank can be pumped from the liquids tank to a urine and wastewater treatment system 300 and can comprise urine, flush water, and trace amounts of toilet paper or other solids.

[00112] FIG. 8 illustrates an example diagram of the buffer tank separation and homogenization system 200. The buffer tank separation and homogenization system 200 can include a belt separator 204, a liquids tank 206, a solids tank 208, and a homogenizer 210. The input stream can be at least one input stream comprising liquids and/or solids and received via at least one inlet. The buffer tank separation and homogenization system 200 can be used receive and separate an input stream of human waste into a solids portion delivered to a solids tank 208 and a liquids portion delivered to a liquids tank 206. The solids tank 208 can contain some liquids and the liquids tank 206 can contain some solids. In each of the liquids tank and solids tank, the solids are separated from the liquids by sedimentation. A liquids output from the liquids tank 206 can be directed for further processing. For example, the liquid effluent from the liquids tank can be a liquids output pumped from the liquids tank to the urine and wastewater treatment system 300. The settled solids in the liquids tank 206 can be removed and/or redirected as an additional input stream to the buffer tank separation and homogenization system 200. The solids output from the solids tank 208 can be directed for further processing. For example, the solids output can be received into a homogenizer 210 to produce a feces slurry delivered to a feces or solids treatment system. A liquid overflow from the solids tank 208 can be removed and/or redirected as an additional input stream to the buffer tank separation and homogenization system 200. The buffer tank separation and homogenization system 200 can also include a controller 215 comprising a processor and memory and configured to operate the belt separator 204 as well as other sensors, valves, actuators, motors, and pumps not shown.

[00113] Shown in FIGS. 9A-9C are bottom, front, and cross-sectional views of the belt separator 204 of the buffer tank separation and homogenization system 200. The belt separator 204 can comprise a perforated belt 214 looped between two rollers 216a, 216b and driven by a motor 218. The belt separator 204 can be positioned to receive an input stream via at least one inlet onto the perforated belt 214 of the belt separator 204. The perforated belt 214 of the belt separator 204 can comprise pores (not shown) configured to allow the liquids portion of the input stream to pass through the perforated belt 214 to the liquids tank 206 and to retain the solids portion on the perforated belt 214. The perforated belt 214 can convey the retained solids toward a scraper or squeegee 220 configured to remove the solids from the perforated belt 214 and direct the solids to the solids tank 208. For example, the perforated belt 214 looped between the two rollers 216a, 216b can be driven at a first end 222 of the belt separator 204 by the motor 218 turning a drive wheel or gear 226 connected to a first roller 216a, with the scraper or squeegee 220 can be positioned at the second end 224. A splash shield 228 can be positioned laterally on both sides of the perforated belt 214, extending at least partially between the first and second ends 222, 224, and configured to direct the at least one input onto the perforated belt 214 such that the solids are also retained on the perforated belt 214.

[00114] The buffer tank separation and homogenization system 200 can receive at least one input stream onto the belt separator 204 via at least one inlet. As shown in FIGS. 9B and 9C, an example buffer tank separation and homogenization system 200 can have individual inlets configured to receive individual ones of the at least one input stream. For example, the individual inlets can be configured for the volume, pressure, flow velocity, and/or expected solids content of the individual input streams of the at least one input stream. For example, the buffer tank separation and homogenization system 200 can comprise a first inlet 230 configured to receive a mostly liquids input, a second inlet 232 configured to receive a mostly solids input, and optionally one or more auxiliary inlets 234 to receive other input streams. For example, the buffer tank separation and homogenization system can include one or more auxiliary inlets 234 configured to receive at least one of: a diverted urine stream, a sludge stream received from a liquids collection tank, an overflow stream received from a solids collection tank, a reject stream received from a liquids treatment system, a filtrate received from a feces treatment system, and a condensed effluent received from a feces treatment system.

[00115] For example, the buffer tank separation and homogenization system 200 can receive a green stream and a brown stream, separately, as two input streams onto a perforated belt 214 of the belt separator 204. The belt separator 204 of buffer tank separation and homogenization system 200 can separate and deliver the solid toilet paper from the green stream to the solids tank and the liquids from the brown stream to the liquids tank. For example, the mostly liquids input stream can be received via a first inlet 230 at a different flow velocity than the mostly solids input stream comprising feces received via a second inlet 232. The second inlet 232 can be configured to receive the mostly solids input stream, having a large solids content, can be delivered under pressure and/or at a high flow velocity, as such the second inlet can be configured to slow the flow velocity as the mostly solids input stream is received. In some examples, the mostly solids stream can be delivered to the buffer tank separation and homogenization system 200 under pressure. The second inlet 232 can comprise an offset chamber inlet 236, an inlet chamber 238 having an interior wall surface 240, and a chamber outlet 242. The second inlet 232 can be configured receive the mostly solids input stream via the offset chamber inlet 236, direct the input stream toward an interior wall surface 240 of the inlet chamber 238 to flow out the chamber outlet 242 onto a perforated belt 214 of the belt separator 204.

[00116] FIGS. 10 and 11 show an example buffer tank separation and homogenization system 200 in greater detail. As shown, the belt separator of FIGS. 9A-9C is secured to a dual chamber enclosure 248. FIG. 11 illustrates a cross-section of the buffer tank separation and homogenization system of FIG. 10. As shown in FIG. 10, a liquids tank 206 and a solids tank 208 are chambers within the enclosure and positioned beneath the belt separator 204. As shown in FIG. 10, the liquids tank 206 includes a liquids tank outlet 252 and a sludge outlet 254. The solids tank 208 includes a solids tank outlet 256 and a recirculation outlet 258. The settled solids output within the solids tank 208 can be routed to the macerator 260 attached to the solids tank outlet 256 so that a uniform feces slurry can be formed. For example, the macerator 260 can be the homogenizer 210, as described herein. The slurry from the macerator 260 can be directed to a feces treatment system via the solids system outlet 262. In some examples, a portion of the contents of the solids tank 208 can also be routed for recirculation via the recirculation outlet 258. The output from the solids tank can be recirculated to the solids tank 208 via recirculation outlet 258. The buffer tank separation and homogenization system 200 can also include a bypass 270 for overflow or circulation of the solids tank 208, where the flow and pressure are adjustable. Additionally, when integrated with other systems such as a urine and wastewater treatment system and/or a feces treatment system liquid portions containing solids, such as filtrate, condensed effluent, and/or filter reject, can be received as input streams for further processing via one or more auxiliary inlets 234.

[00117] Illustrated in FIG. 11 is a cross-sectional view of an example buffer tank separation and homogenization system 200. The buffer tank separation and homogenization system 200 can include the belt separator 204, a liquids tank 206, and a solids tank 208. In this example, the liquids tank 206 and the solids tank 208 are chambers contained within the same dual chamber enclosure 248, although the design can be implemented and relied upon in other configurations such as physically separate tanks. In this example, the belt separator 204 is positioned above a portion of the liquids tank 206 and a portion of the solids tank 208 and is configured to receive an input stream from the first inlet 230, the second inlet 232, or an individual one of the plurality of auxiliary inlets 234 onto the perforated belt 214. A liquid portion of the input stream can flow by gravity into the liquids tank 206. A solids portion of the input stream can be conveyed by the moving perforated belt 214 towards the solids tank 208. A scraper or squeegee 220 can be positioned at the second end 224 of the belt separator 204 and configured to remove solids from the moving perforated belt 214. A liquid deflector 264 can be positioned beneath the second end 224 of the belt separator 204 to capture and channel liquids to the liquids tank 206 as the solids are removed from the perforated belt 214 or liquids received onto the perforated belt 214 that flow toward the second end 224. [00118] The liquids tank 206 is configured to clarify the fluids received by allowing solid particles to settle. In some examples, the liquids tank 206 can include a bottom wall 266 inserted into the liquids tank 206 or formed in the body of the liquids tank 206. The bottom wall 266 can be angled or shaped to direct a sludge of the settled solids to a sludge outlet 254. In an example, a sludge stream of settled solids can be delivered to the belt separator 204 to remove any liquid content and direct the solids to the solids tank 208. In another example, the settled solids can be delivered directly to the solids tank 208. A clarified liquid stream can be released via a liquids tank outlet 252. The liquids tank 206 can also include a baffle or weir (not shown) to help reduce the number of particulates that enter the liquids tank outlet 252. In an example, the clarified liquid stream output can be released via natural overflow. In another example, the clarified liquid stream output can be released via a valve system or pumped. For example, the clarified liquid stream output can be delivered to a urine and wastewater treatment system 300.

[00119] The solids tank 208 is configured to receive solids separated by the belt separator 204 and to allow solid particles to settle and extract liquids. In some examples, the solids tank 208 can include a bottom wall 268 inserted into the solids tank 208 or formed in the body of the solids tank 208. The bottom wall 268 can be angled or shaped to direct the settled solids to the solids tank outlet 256. The solids tank outlet 256 is connected to a homogenizer 210 configured to mix, grind, or macerate the settled solids from the solids tank 208 to a slurry that can be delivered from the buffer tank separation and homogenization system 200 and transported to a feces treatment system for removal of pathogens. The buffer tank separation and homogenization system 200 can also include a bypass 270 (FIG. 10) for overflow or circulation of the solids tank 208, where the flow and pressure are adjustable. In some examples, the liquid phase separated from the solids can be recirculated as input through an auxiliary inlet 234 and received as an input onto the belt separator 204.

[00120] The buffer tank separation and homogenization system 200 can also comprise additional valves, sensors, switches, actuators, pumps, and the like to facilitate the operation of the buffer tank separation and homogenization system 200. Further, the buffer tank separation and homogenization system 200 can comprise a controller to operate at least the valves, sensors, switches, actuators, and pumps of the system. The buffer tank separation and homogenization system 200 can also include vent outlets for one or more of the tanks described herein. For example, the solids tank 208 can have an air exhaust vent 272 (FIG. 10). Each vent outlet can be connected to a main gas exhaust line with a gas filter. For example, when the buffer tank separation and homogenization system 200 is a module in a single unit toilet system, the main exhaust line can also receive gas vented from other modules of the single unit toilet system. The gas filter can be configured so that the filtered gas release from the system is ISO 30500 compliant.

[00121] FIG. 12 shows an example method for buffer tank separation and homogenization as described herein. Although the method shown provides an example for producing an output for both the liquids tank and solids tank, steps can be added, omitted, or performed in a different sequence. For example, a single input stream can comprise a solids portion and a liquids portion. The method for processing the solids portion and liquids portions are shown separately, as liquids and solids outputs are processed in separate tanks, but the steps may occur simultaneously or in some other sequence.

[00122] At box 1202, the method can include receiving, onto a belt separator, an input stream comprising at least one of: solids and liquids. The buffer tank separation and homogenization system 200 can receive one or more input streams from separate sources. For example, a first input can be considered the green stream, as described herein, comprising mostly liquid with some solids, for example, toilet paper. In an example, a second input comprising at least feces and water can also be received separately via a second inlet. The second input can be considered the brown stream, as described herein, containing solids. For example, the second input can include feces, toilet paper, urine, and/or water. In some examples, a urine stream or yellow stream can be received via an auxiliary inlet. Although the urine stream is primarily urine, some trace amounts of toilet paper or other solids, if present, can be captured by the belt separator. As previously discussed, additional input streams can be received via one or more of the auxiliary inlets including: a sludge stream received from the liquids collection tank, an overflow stream received from the solids collection tank, a reject stream received from a liquids treatment system, a filtrate received from a feces treatment system, and a condensed effluent received from a feces treatment system. More than one input stream can be received separately or simultaneously.

[00123] At box 1204, the method can include separating, by the belt separator, the input stream into a solids portion and a liquids portion. For example, the toilet paper and other solids can be removed from an input stream that is mostly liquid with some solids. Similarly, the liquids can be removed from an input stream that is mostly solids with some liquids. The perforated belt of the belt separator can comprise pores configured to allow the liquids portion of the input stream to pass through to the liquids collection tank and to retain the solids portion on the perforated belt.

[00124] At box 1206, the method can include delivering the liquids portion to a liquids tank for sedimentation. The liquids portion of the input stream is allowed to pass through to the liquids collection tank. In some examples, at least some of the liquids portion of the input stream is directed to the liquids collection tank via a liquid deflector positioned beneath the belt separator.

[00125] At box 1208, the method can include separating, by sedimentation, at least a collected liquids portion and a sludge of settled solids. In the liquids collection tank, the solids are allowed to settle to the bottom of the liquids tank forming a collected liquids portion and a sludge. The liquids tank can include or be formed with a bottom wall that directs the separated solids toward a sludge outlet.

[00126] At box 1210, the method can include releasing a collected liquids portion from the liquids collection tank. In an example, the collected liquids portion output can be released natural overflow. In another example, the collected liquids portion output can be released via a valve system. For example, the collected liquids portion output can be delivered to a urine and wastewater treatment system. In some examples, the method can also include receiving a concentrate from a urine and wastewater treatment system via an auxiliary inlet. In some examples, at box 1212, the method can also include delivering, periodically, at least a portion of the contents of the liquids collection tank to the belt separator. For example, the sludge portion of the liquids collection tank can be delivered to the belt separator via an auxiliary port.

[00127] At box 1214, the method can include delivering the solids portion to a solids tank for sedimentation. The solids portion of the input stream can be retained on the perforated belt and conveyed to the solids collection tank. In some examples, at least some of the solids portion of the input stream can be removed from the belt using a stationary squeegee that scrapes the retained solids from the belt. For example, the solids portion can comprise feces and/or toilet paper from at least one input stream.

[00128] At box 1216, the method can include separating, by sedimentation, contents of the solids collection tank into at least a concentrated solids portion. The feces, toilet paper, and other solid particles can settle to the bottom of the solids collection tank, forming a concentrated solids portion. [00129] At box 1218, the method can include delivering the concentrated solids portion to a homogenizer to form a slurry. The homogenizer can be a bladed macerator configured to transform the collected solids output in the solids tank into a uniform and homogenized slurry for transport to the treatment modules.

[00130] At box 1220, the method can include releasing the slurry output. For example, the slurry can be delivered to the slurry output to feces treatment system for further processing and removal or destruction of pathogens or contaminants. In some examples, the method can also include receiving a liquid effluent from a feces treatment system via an auxiliary inlet to the belt separator for separation. In some examples, at box 1222, the method can also include delivering, periodically, at least a portion of the contents of the solids collection tank to the belt separator or recirculating a portion of the solids tank via another inlet.

[00131] FIGS. 13A-13D further illustrate the operation of the buffer tank separation and homogenization system 200 by illustrating the flow within the system based on different waste events. The waste events can be determined by a user or detected by a sensor or simply directed to predetermined inlets of the buffer tank separation and homogenization system 200. As described herein, a green stream can be mostly liquid with some solids, a brown stream can be mostly feces and can also be mixed with other liquid and solid waste, and a yellow stream can be primarily urine.

[00132] Shown in FIG. 13 A, for a urination event, a green stream can be received onto the belt separator 204 as the input stream. In some examples, a yellow stream can be received onto the belt separator 204. The liquids are delivered to the liquids tank 206 by passing through the perforated belt. As much toilet paper as possible is removed from the input stream by the belt separator 204 and delivered to the solids tank 208. After the solids have settled from the contents of the liquids tank, a collected liquids portion can be released. The liquids tank 206 can include a baffle or weir to help reduce the number of particulates that enter the liquids tank outlet 252.

[00133] In FIG. 13B, for a defecation event, a brown stream comprising feces, toilet paper, some urine, and some water can be received as the input stream. The liquids from the brown stream can be delivered through the perforated belt to the liquids tank 206. The solids from the brown stream can be delivered to the solids tank 208. The collected solids output can be delivered to the homogenizer and then to a feces treatment system for further processing. [00134] FIG. 13C. illustrates an example of recirculating the contents of the liquids tank 206. There can be a buildup of solids in the liquids tank 206. Periodically, the sludge settled solids of the liquids tank 206 can be recirculated to the top of the belt separator 204 for a separation loop. For example, the liquids tank 206 can be recirculated about 2-3 times a day. The recirculation can improve the solid/liquid separation and prevent stagnation in the liquids tank 206.

[00135] FIG. 13D illustrates an example of a similar recirculation process for the solids tank 208. There can be a buildup of solids in the solids tank 208. Periodically, a portion of the contents of the solids tank 208 can be recirculated to the top of the belt separator 204 for a separation loop. For example, the solids tank 208 can be recirculated every 1-2 days. The recirculation can improve the solid/liquid separation and prevent stagnation in the solids tank 208.

[00136] URINE AND WASTEWATER TREATMENT SYSTEM

[00137] FIGS. 14 and 15 illustrate the urine and wastewater treatment system 300 of the volume reduction non-sewered single unit toilet system 10. As shown in FIG. 14, the urine and wastewater treatment system 300 can comprise an ultra-filtration (UF) stage comprising an ultra filtration (UF) membrane filter 304 and a reverse osmosis (RO) stage comprising a reverse osmosis (RO) membrane filter 312. The UF stage can also include a diffuser 322 positioned at an inlet 303 to the UF membrane filter 304, a permeate pump 306, and a reservoir tank 308. An air blower 314 can be connected to the diffuser 322 and configured to introduce air into fluid as it is received into the UF membrane filter 304. The RO stage can also include a high-pressure pump 310 and a permeate tank 316. Additionally, the reservoir tank 308 can receive RO concentrate from the RO stage and a concentrate tank 318 can be in fluid connection with the reservoir tank 308.

[00138] A buffer tank 302 can optionally be included in the urine and wastewater treatment system 300 and be configured to receive and hold liquid waste to be treated. Alternatively, the buffer tank 302 can be omitted and an external tank or buffer tank system that receives urine and/or wastewater can serve as the feed for the UF. For example, the urine and wastewater treatment system 300 can be connected to a liquids buffer tank 206 in a buffer tank separation and homogenization system.

[00139] In an example, the urine containing stream can be a green stream, as described herein, that comprises mostly urine, but can also include water and/or some trace solids, such as toilet paper. In some examples, the green stream can be processed prior to being received by the urine and wastewater treatment system 300. For example, a buffer tank separation and homogenization system can collect and reduce the solids in a human waste stream from a frontend user receptacle or other urine containing streams to clarify the liquid by separating at least a portion of solid particles. For example, the buffer tank 302 can be a liquids tank 206 of a buffer tank separation and homogenization system 200. For example, the liquids tank outlet 252 of the buffer tank separation and homogenization system 200 can be in fluid connection with the to the inlet 303 of the UF filter via a diffuser 322.

[00140] The UF membrane filter 304 can be in fluid connection with the buffer tank 302, for example via the diffuser 322. The liquid waste can receive into the UF membrane filter 304 such that an air blower 314 introduces air into the liquid via the diffuser 322 before it passes over the UF membrane filter 304. Mixing the air and liquid reduces the density of the liquid and displaces the liquid upward, generating crossflow over the UF membrane filter 304 to separate a first permeate stream and a first concentrate stream. For example, the fluid mixed with air reduces the density of the fluid and displaces it upwards generating cross flow through the filter forming the UF permeate. The fluid that does not pass through the filter is the UF concentrate.

[00141] A permeate pump 306 can deliver the UF permeate stream, also called the first permeate stream herein, to a reservoir tank 308. The UF concentrate stream, also called a first concentrate stream herein, can be released as an output. For example, the UF concentrate can be delivered to the buffer tank 302. In some examples, if the urine and wastewater treatment system 300 is fluidically connected to the buffer tank separation system 200, the first concentrate stream can be delivered to the buffer tank separation system 200.

[00142] As shown in FIG. 14, the reservoir tank 308 can receive the first permeate of the UF membrane filter 304 via the permeate pump 306, which are all fluidically connected. A high- pressure pump 310 can transport the fluid from the reservoir tank through a RO membrane filter 312 at a high pressure to separate a second permeate stream and a second concentrate stream. In an example, the second concentrate stream, also called the RO concentrate herein, can be returned to the reservoir tank 308. In some examples, a portion of the second concentrate can be recirculated through the RO membrane filter 312. The majority of the second concentrate stream can be directed to a concentrate tank 318. The second permeate stream, also called the RO permeate herein, can be considered clean and/or usable water. The second permeate stream can be directed to a permeate tank 316 for holding and/or directed for use in a flush tank or discharged to another system or the environment. For example, the second permeate stream can be ISO 30500 compliant to be safely discharged into the environment.

[00143] The buffer tank 302, or liquids tank from another system, can be fluidically connected to the UF membrane filter 304 via a conduit such as tubing or other means. The UF membrane filter 304 can operate at a low pressure. For example, the liquid stream between the buffer tank 302 and the UF membrane filter 304 can be a low-pressure stream, having a pressure of about atmospheric pressure or about 1 atm and having a temperature of about 20-40°C. An air pump or air blower 314 can be positioned to introduce air to the fluid flow of the liquid stream at the feed to the UF membrane filter 304. For example, the air blower 314 can diffuse air into the liquid stream using diffuser 322, such as an air stone. The UF membrane filter 304 can separate fluid received into a first permeate and a first concentrate, where the first permeate is the portion of fluid that passes through the UF membrane filter 304 and the first concentrate is the fluid rejected by the UF membrane filter 304. In some examples, if the urine and wastewater treatment system 300 is fluidically connected to a buffer tank separation system 200 and processed with the other fluids.

[00144] A permeate pump 306 can deliver the first permeate to a reservoir tank 308 at a low pressure. A high-pressure pump 310 can be fluidically connected between the reservoir tank 308 and the RO membrane filter 312. The high-pressure pump 310 can be configured to output a fluid at a higher pressure than the intake. For example, the high-pressure pump 310 can pump the first permeate from the reservoir tank at a low pressure, then deliver the fluid to the RO membrane filter 312 at a high pressure. For example, the low pressure can be about 1 bar and the high pressure can be about 30-35 bar. In some examples, a relief valve 324 can be positioned in the high-pressure conduit to return a portion of the pressurized first permeate liquid stream to the reservoir tank 308. The high-pressure pump 310 can deliver the first permeate liquid stream to the RO membrane filter 312 at a high pressure. For example, the high-pressure fluid feed to the RO membrane filter 312 can be about 435 psi and having a temperature of about 20-40°C. The RO membrane filter 312 can separate fluid received into a second permeate and a second concentrate, where the second permeate is the portion of fluid that passes through the RO membrane filter 312 and the second concentrate is the fluid rejected by the RO membrane filter 312. The RO membrane filter 312 can be fluidically connected to a permeate tank 316 configured to receive the second permeate. The RO membrane filter 312 can be fluidically connected to a concentrate tank 318 configured to receive the second concentrate. The second permeate stream can be directed to a permeate tank 316 for holding and/or directed for use in a flush tank or discharged to another system or the environment. For example, the second permeate stream can be ISO 30500 compliant to be safely discharged into the environment. The second concentrate stream can be returned to the reservoir tank 308 and a portion can be recirculated by the high-pressure pump 310 through the RO membrane filter 312.

[00145] The concentrate tank 318 can hold the RO concentrate delivered from the reservoir tank 308. At least a portion of the collected RO concentrate, also called RO reject herein, can be released to another system for further processing. For example, the RO reject can be delivered to another system, such as a solids treatment system, for a concentration process for discharge. The RO concentrate can comprise solids and/or salts filtered from the liquid stream of the urine and wastewater treatment system 100. In some examples, the RO reject can be received into a concentrator (not shown) of a solids treatment system. For example, a concentrator can be configured to receive a liquid waste that can be heated. In an example, the RO reject from the urine and wastewater treatment system 300 can be received into the concentrator. Humidified air and/or an off gas can be released, and a concentrated output can be delivered to another system for further treatment or discharged from the system. The humidified air and/or off gas can be delivered to a main exhaust outlet and filtered before being released into the atmosphere. The gas filter in the main exhaust outlet can be configured such that the gas released is ISO 30500 compliant.

[00146] The buffer tank 302, the reservoir tank 308, the permeate tank 316, and the concentrate tank 318 can each have a vent outlet to release air or any gas in the respective tanks (not shown). Each of the vent outlets can be connected to a main gas exhaust line with a gas filter. For example, when the urine and wastewater treatment system 300 is a module in a single unit toilet system, the main exhaust line can also receive gas vented from other modules of the single unit toilet system. The gas filter can be configured so that the filtered gas release from the system is ISO 30500 compliant.

[00147] The urine and wastewater treatment system 300 can also comprise additional valves, sensors, switches, actuators, pumps, and the like to facilitate the operation of the urine and wastewater treatment system 300. For example, the buffer tank 302, the reservoir tank 308, the permeate tank 316, and/or the concentrate tank 318 can have sensors to detect the level of fluid in the respective tank. The urine and wastewater treatment system 300 can also comprise a controller 315. The controller 315 can be configured to interface with the valves, pumps, sensors, switches, and/or actuators in the system. For example, the controller 315 can be configured to operate the valves and/or pumps in response to a sensor indication from a tank, where the tank may have one or more sensors to indicate the level of the fluid within the tank. The controller 315 can be configured to control only the operation of the components of the urine and wastewater treatment system 300. In some examples, the controller can be integrated in a control system for a single unit toilet system in which the urine and wastewater treatment system 300 resides as a module.

[00148] FIG. 15 shows an example method for collection and separation of human waste as described herein. At box 1302, the method can include receiving a liquid waste from a tank. For example, the liquid waste can be received from a buffer tank. In some examples, the liquid waste can be urine and/or wastewater. For example, the liquid waste can be a clarified green stream, as described herein, comprising urine, water, and/or some trace toilet paper after at least a portion of solids have been removed. In some examples, the buffer tank that is external to the urine and wastewater treatment system 300.

[00149] At box 1304, the method can include blowing air into the liquid waste stream to reduce the density of the liquid waste and to generate crossflow. For example, as discussed with respect to FIG. 1, the air pump or air blower can be positioned to introduce air to the fluid flow of the liquid stream at the feed to the UF membrane. For example, the air blower can diffuse air into the liquid stream using an air stone causing a bubbling effect. In another example, the air can be introduced by another distribution method.

[00150] At box 1306, the method can include filtering the liquid waste stream in an ultra- filtration stage to separate a first permeate and a first concentrate. The fluid can be filtered using an ultra-filtration membrane to separate a first permeate and a first concentrate. The fluid from the buffer tank and air mixing reduces the density of the fluid and displaces it upwards generating cross flow through the filter forming the first permeate.

[00151] At box 1308, the method can include discharging the first concentrate. The first concentrate from the UF membrane filter can contain some solids. The first concentrate can be discharged and/or returned to a pre-processing system for separation of solid waste in concentrate. For example, the concentrate can be returned to the same system that pre-processed green stream to clarify the green stream, then clarified and recirculated in the urine and wastewater treatment system. The first permeate, most of solids removed, can be directed to a next stage of filtering. For example, the first permeate can be pumped to a reservoir tank. [00152] At box 1310, the method can include filtering the first permeate in a reverse osmosis stage to separate a second permeate and a second concentrate. The reverse osmosis stage can operate at a high pressure. For example, the first permeate can be delivered to a reverse osmosis membrane filter via a high-pressure pump. The first permeate can be filtered in the reverse osmosis membrane filter to separate a second permeate and a second concentrate. At box 1312, the method can include discharging the second permeate. In some examples, the second permeate can be reused. In some examples, the second permeate can be ISO 30500 compliant. Techniques for measuring chemical oxygen demand (COD), total nitrogen (total N), total phosphorus (total P), pH, total suspended solids (TSS), and E. coli (colony forming units or CFUs) are provided in the Examples.

[00153] As can be understood, the example method can be carried out in the order recited or in any other order that is logically possible. The method can omit steps or include additional steps. For example, the method can include a cleaning cycle. The cleaning cycle can include a backflow or pumping of a cleaning fluid through the system. In some examples, the method can be implemented automatically by the controller 315 based on sensor values, state of operation, user input, or other factors.

[00154] For example, the controller 315 can interface with sensors, valves, pumps, and motors of urine and wastewater treatment system 300. The controller 315 can comprise at least a processor and memory. The controller can be configured to implement a sequence of instructions to operate the sensors, valves, pumps, and motors based on the state of operation of the UF membrane filter 304 and/or the RO membrane filter 312. For example, the controller 315 can detect a level of fluid in each of the buffer tank 302, reservoir tank 308, permeate tank 316, and concentrate tank 318 via sensors in each of the respective tanks. For example, the controller 315 can actuate valves to empty said tanks and/or operate pumps to deliver fluids from said tanks. For example, the controller 315 can implement instructions for an RO flush cycle by turning off the high-pressure pump 310, closing an RO inlet valve, and draining the reservoir tank 308. After a time to drain the reservoir tank 308 to the concentrate tank 318, open the RO flush valve, turn on the high- pressure pump 310 and run the flush cycle for a predetermined time. For example, the liquid waste can be filtered by using a sensor to detect that the buffer tank 302 is full, the reservoir tank 308 is not full, and the RO flush cycle is complete. The controller 315 can implement instructions to start the UF sequence by turning on the air blower 314 and turning on the permeate pump 306 to filter the liquid waste pumped from the buffer tank 302. After a time has elapsed, the permeate pump 306 and air blower 314 can be turned off, then the concentrate can be drained from the UF membrane filter 304.

[00155] VOLUME REDUCTION SOLIDS TREATMENT SYSTEM

[00156] FIGS. 16-22 illustrate the volume reduction solids treatment system 500 of the volume reduction non-sewered single unit toilet system 10 in greater detail. The volume reduction solids treatment system 500 can be configured to process a feces stream or brown stream of human waste. By separating the brown stream prior to input into the volume reduction solids treatment system, the system can operate to process the solids contained therein. Moreover, a brown stream slurry can be obtained by removing excess fluid from the brown stream and homogenizing the contents. For example, a brown stream slurry can be obtained in a system or module connected to the volume reduction solids treatment system 500. In an example, a brown stream can be received into a collection tank and processed into a slurry. In an example, the collection tank can be a stream mixing vessel to receive more than one waste stream.

[00157] The volume reduction solids treatment system 500 can include a pasteurization and volume reduction process for the treatment of human waste in a toilet environment to produce pathogen free feces cakes suitable either for combustion and reduction to ash or disposal by other means. In some examples, the volume reduction solids treatment system can operate as part of a single unit toilet system. The feces slurry can pass into a pasteurization heater where it is held at elevated temperatures until pathogen kill is achieved. The treated waste slurry can be transferred at elevated temperatures to a mechanical dewatering filter press. The treated slurry can then be compressed, and the volume reduced solid waste can be ejected from the filter press as a feces cake onto a conveyor. The change in volume of the input slurry to the feces cake output can be evaluated in terms of change in water content. For example, the input slurry moisture content can be 96-99% and the output pressed cake moisture content can be 28-84%. This reduction in water content corresponds to at least an 80% reduction in volume. The reduction in volume can be greater than 95%.

[00158] In an example, the removed liquid phase can be transported out of the system for treatment in a separate liquid treatment system. In an example, the conveyor can transport the feces cakes to the disposal bin over a period of 8-10 hours. In an example, the conveyor can be housed in a drying tunnel. The drying tunnel being a contained air duct system to enable forced air to be propelled over the cakes to provide evaporative drying of the cakes during transport. The final cakes can have 4-10% moisture content and be deposited in a removable bin for subsequent disposal. In an example, the feces cakes can be reduced to ash in the external combustion system 600.

[00159] As shown in FIG. 16, the volume reduction solids treatment system 500 can include a pasteurizer 502, a filter press 504, and a drying tunnel 506. The volume reduction solids treatment system 500 is configured to receive a feces slurry and produce feces cakes that are pathogen free. The volume reduction solids treatment system 500 can also comprise a controller 515 to operate the valves, pumps, motors, actuators, switches, and sensors (not shown). The feces slurry is a slurry that comprises feces, but can include other waste. As described herein, the feces slurry can be a brown stream slurry, that can include feces, urine, toilet paper, and/or water. The feces slurry can be received from a separate system that comprises a homogenizer to break down the solid waste to a uniform particle size. For example, the homogenizer can be a macerator or grinder, and the like. In some examples, the feces slurry can be received from a system that separates liquids and solids from a mixed-content human waste stream. In some examples, the feces slurry can be received from a buffer tank that holds solids waste.

[00160] A batch of feces slurry can be received into the pasteurizer 502. In some examples, a batch of feces slurry can be received directly from a separation and homogenization system or another system comprising a homogenizer that forms the feces slurry from solids separated from a human waste stream. The batch of feces slurry can be heated in the pasteurizer 502 at an elevated temperature for a period of time sufficient to kill pathogens. For example, the elevated temperature can be at least 85°C. For example, the batch of feces slurry can be treated in the pasteurizer 502 for about 10 min at about 95°C. The treated output from the pasteurizer 502 can be a pathogen free or pathogen reduced feces slurry. In an example, the pasteurizer 502 can process 6L a day of feces slurry in 100 mL batches to achieve pathogen reduction. In some examples, the treated slurry output of the pasteurizer is ISO 30500 compliant.

[00161] The treated slurry can be delivered from the pasteurizer 502 to the filter press 504. The filter press 504 can be a mechanical dewatering filter press that comprises a solids chamber 514, a piston 516, and a filter gate 518. The filter press 504 can receive the treated slurry, also called a pasteurized brown stream herein, into a solids chamber 514. The filter press 504 is configured to actuate a piston 516, reducing the volume of the solids chamber 514, and compressing the treated slurry against the filter gate 518 to form a feces cake. The filter gate 518 comprises a filter screen 520. For example, the filter screen 520 can be filter screen can be 41-160 pm nylon net, 140-508 pm stainless steel mesh, or other perforated plate. For example, the filter screen 520 can be a 508pm stainless steel mesh filter. Compressing the treated slurry can extract liquids from the slurry, which can be output via filter gate 518. The extracted liquid, or filtrate, can be collected. In some examples, the filtrate can be delivered to a separation and homogenization system to separate particulates.

[00162] The filter gate 518 can translate to shear the feces cake off the filter and open the chamber, ejecting the feces cake. In an example, a squeegee 522 can be driven by a motor 524 and belt drive 525 to deliver the wet feces cake to a drying tunnel 506. The drying tunnel 506 can comprise a dryer belt or conveyor 530. The drying tunnel 506 can reduce the moisture content of the filter cakes thru the sticky phase to a level that will allow release from the belt and solids container. In an example, the drying tunnel 506 can comprise conveyor 530 housed in a contained air duct system 534 configured to propel forced air over the feces cakes to provide evaporative drying of the feces cakes during transport. For example, the conveyor 530 can transport the feces cakes to a solids disposal bin 532 over a period of 2-3 hours.

[00163] In some examples, the volume reduction solids treatment system 500 can also comprise a concentrator 512 or interface with a concentrate tank of a liquids treatment system. The concentrator can be a pasteurization and evaporation module. For example, the mixed waste can be separated into liquids and solids prior to input to the volume reduction solids treatment system 500. The liquids treatment system can output rejected fluids that contain solids and cannot be treated in the liquids treatment system. The rejected fluids can be reduced in volume by heating the fluids in the concentrator 512. In an example, pressurized air can be introduced into the concentrator such that humidified air and/or an off gas is released, and a concentrate remains. The condensed effluent or concentrated volume can be delivered to the drying tunnel 506 to remove remaining moisture content. In an example, the drying tunnel 506 can receive a concentrate from a liquids treatment system. For example, the drying tunnel 506 can evaporate up to 4 L/day or more of concentrate. In some examples, the drying tunnel 506 can further comprise a means to discharge gas.

[00164] FIGS. 17A and 17B illustrate rear and front views of an example volume reduction solids treatment system 500 of FIG. 16. In this space saving example, a feces slurry is received into the pasteurizer inlet 546 and flows through the tubing 540 of the pasteurizer 502 to the pasteurizer outlet 548. The pasteurizer outlet 548 is in fluid communication with the filter press inlet 526. After pasteurization, the treated slurry can be delivered via the pasteurizer outlet 548 to the filter press 504. The filter press 504 can operate to form the feces cakes to be released from a filter press outlet 528. The feces cakes can be conveyed on in the drying tunnel 506 for a period of time to be released via a drying tunnel outlet 550 (FIG. 17B) to the solids disposal bin 532.

[00165] As shown in FIG. 17B, the drying tunnel 506 can comprise dryer belt 536 housed in a contained air duct system 534 to force air over the feces cakes (not shown) to provide evaporative drying of the feces cakes during transport. The drying tunnel 506 having a proximal end 552 and a distal end 554, with the dryer belt 536 extending about rollers 538a, 538b positioned at each of the proximal and distal ends 552, 554. The dryer belt 536 is configured to convey the feces cake from where the feces cake is delivered from the filter press 504 the proximal end 552 to the distal end 554, where the feces cake is released into a solids disposal bin 532. In some examples, the dryer belt 536 is arranged with an incline from the proximal end 552 to the distal end 554. In some examples, the dryer belt 536 can comprise a mesh to allow air flow. For example, the dryer belt 536 can be made of a polymer mesh or a metal mesh. As shown in this example, the volume reduction solids treatment system 500 can also include a solids disposal bin 532 to receive the dried or mostly dried feces cakes. The feces cakes can be transferred in the solids disposal bin 532 by user to a combustor or suitable system for reduction to ash or disposal by other means.

[00166] FIGS. 18A and 18B illustrate the example pasteurizer 502 of FIG. 17A in greater detail. The pasteurizer 502 can include tubing 540 and one or more heaters 542a-d (separately “heater 542,” collectively “heaters 542”). For example, the feces slurry can be received into the tubing 540 at the pasteurizer inlet 546, heated by the heaters 542a-d at an elevated temperature for a period of time sufficient to kill pathogens, with the treated slurry output through the pasteurizer outlet 548. In this example, a heater 542 can be a heater wrap configured to surround the tubing, although other types and configurations of heaters can be relied upon and implemented. Valve 556 at the pasteurizer inlet 546 and valve 558 at the pasteurizer outlet 548 can each be configured to control the flow of the slurry through the respective pasteurizer inlet 546 or pasteurizer outlet 548. The pasteurizer 502 can also include a flush water inlet 560 and valve 562 configured to receive an input of water for flushing of the tubing 540. For example, valves 556, 558, 562 can be two-way valves. The pasteurizer 502 can also include a pressure release valve 564 and a rupture pressure outlet 568 to protect the pasteurizer 502 during an overpressure event.

[00167] For example, the batch of feces slurry can be treated in the pasteurizer 502 for about 10 min at about 95°C. In an example, the heaters 542 can be independently controlled to enable more energy efficient heating. For example, a plurality of zones can be formed along the length of the tubing using a plurality of heaters 542 with independent temperature control. As an example, as shown in FIG. 18 A, the one or more heaters 542a-542d can be a plurality of sections of heater wrap wrapped around the tubing 540, forming a plurality of heating zones independently controlled via a plurality of control thermocouple ports 544a-d (separately “thermocouple port 544,” collectively “thermocouple ports 544”). In this example, thermocouple ports 544 are shown for temperature control, although other types and configurations of devices to measure and control temperature of the heaters 542 can be relied upon and implemented. In an example, the pasteurizer can be configured such that the output meets an ISO 30500 required pathogen reduction. For example, the Escherichia coli ( E . coli ) counts in final solid output can be less than 100 per g. In some examples, the E. coli counts can range from 19 to 2395 per g material. In some examples, the E. coli counts can be below detection limits.

[00168] FIGS. 19A-19D illustrate the example filter press 504 of FIG. 17A in greater detail. The treated slurry can be received into a solids chamber 514 of the filter press 504. The solids chamber 514 can be cylindrical in shape and configured to receive the piston 516. The piston 516 can be actuated to reduce the volume of the solids chamber 514 and apply pressure to the treated slurry against the filter gate 518 to form a feces cake. The extracted fluid can pass through the filter gate 518 to be collected or delivered to another treatment system. The feces cake can be released to the drying tunnel 506 via a filter press outlet 528.

[00169] FIG. 19B illustrates a cross sectional view of a portion of the filter press 504 of FIG. 19A. The treated slurry can be received into a solids chamber 514 of the filter press 504 via the filter press inlet 526. As indicated by the horizontal arrow, the piston 516 can compress the slurry against filter screen 520 to form a feces cake.

[00170] FIG. 19C illustrates an exploded view of the filter assembly 570 of the filter gate 518. The filter assembly 570 comprises a filter screen 520, a filter support screen 572, a drain spacer 574, the filter press inlet 526, and a check valve 576. The filter assembly 570 can also include seals 578a, 578b for the filter assembly 570. The slurry can be received via the filter press inlet 526 and introduced into the solids chamber 514 via a check valve 576. As indicated by the vertical arrow shown in FIG. 19D, the squeegee 522 can translate to remove the feces cake from the filter screen 520 to release the feces cake to the drying tunnel 506.

[00171] FIG. 20 illustrates a cross section of the drying tunnel 506 shown in FIG. 18B in greater detail. The feces cakes can be received from the filter press 504 via a drying tunnel inlet 529. The drying tunnel 506 is configured to force air over the feces cakes (not shown) to provide evaporative drying of the feces cakes during transport. The drying tunnel 506 having a proximal end 552 and a distal end 554, with the dryer belt 536 extending about rollers 538a, 538b positioned at each of the proximal and distal ends 552, 554. The dryer belt 536 is configured to convey the feces cake from where the feces cake is delivered from the filter press 504 the proximal end 552 to the distal end 554, where the feces cake is released via the drying tunnel outlet 550. In some examples, the drying tunnel 506 can also receive solids output separately from the concentrator 512.

[00172] When volume reduction solids treatment system 500 is part of a non-sewered single unit toilet system, the concentrator 512 can receive rejected fluids containing salts and/or other particulate solids from the urine and wastewater treatment system 300. FIGS. 21A and 21B illustrate the concentrator 512 of the volume reduction solids treatment system 500. The concentrator 512 can be a pasteurization and evaporation module that can interface with a concentrate tank of a liquids treatment system. For example, the liquids treatment system can output rejected fluids that contain solids and cannot be treated in the liquids treatment system. The rejected fluids can be reduced in volume by heating the fluids in the concentrator 512. In an example, pressurized air can be introduced into the concentrator such that humidified air and/or an off gas is released, and a concentrate remains.

[00173] As shown in FIG. 21 A, the concentrator 512 can comprise an open concentrator vessel 580 configured to hold a volume of fluid and a plurality of discs 586 housed within the open concentrator vessel 580. As shown in the cross-sectional view in FIG. 21B, the plurality of discs 586 can be arranged about an axle 588 that can be rotated by a motor 590 such that at least a portion of the plurality of discs can be wetted by the fluid as the axle 588 rotates. A heater 592 can comprise heating coils 594. The heater 592 can be positioned such that heating coils 594 extend into the open concentrator vessel 580 and configured to heat the volume of fluid contained within the open concentrator vessel 580. In some examples, the concentrator module 512 can also include an include an enclosure 182 positioned over the open concentrator vessel 180. In some examples, the concentrator module 112 can further comprise an air intake 583 and an air outlet 585 to provide air flow over the plurality of discs 566, that are wet, to aid in evaporation of the fluids to be concentrated. For example, a blower (not shown) or one or more fans 584 can direct air flow through the concentrator 512. As shown in FIG. 6A, the enclosure 582 can comprise one or more fans 584a-c (separately “fan 584,” collectively “fans 584”) positioned to draw air through the concentrator vessel 580 and over the plurality of discs 566. The air intake 183 can be a gap between the open concentrator vessel 580 and an enclosure 582. In another example, a system blower (not shown) can provide airflow in a similar manner over the plurality of discs 566 to aid in evaporation of the fluids to be concentrated.

[00174] The concentrator 512 can receive a can receive a volume of rejected fluids containing salts and/or other particulate solids from the urine and wastewater treatment system 300. The volume of fluid can be contained by the open concentrator vessel 580. The volume of fluid can be maintained at a level that does not flow over or interfere with the rotation of the axle 588. The volume of fluid can be heated by the heater 592 and heating coils 594 to aid in evaporation of the fluid. As the plurality of discs are rotated through the heated volume of fluid, the air intake can be configured to direct air into the concentrator 512 over the plurality of discs 586 such that the fluid evaporates leaving the solids of the fluid received. The arrows shown in FIG. 21 A indicate a direction of air flow for evaporation in one example. In another example, the air intake 583 and air outlet 585 can be reversed such that the air flow is provided in the opposite direction. For example, the fans 584 can be configured to draw air through the concentrator 512 or to operate in a reverse direction to blow air into the concentrator 512 and out the gap between the open concentrator vessel 580 and an enclosure 582.

[00175] In one example, the condensed effluent or concentrated volume can be delivered to the drying tunnel 506 to remove remaining moisture content. In an example, the drying tunnel 506 can receive a concentrate from the concentrator 512. For example, the drying tunnel 506 can evaporate up to 4 L/day or more of concentrate. In some examples, the drying tunnel 506 can further comprise a means to discharge gas. In another example, up to 50% of the volume contained within the open concentrator vessel 580 can be returned to the buffer tank separation system 200 for further processing. [00176] Although not shown in the figures, the volume reduction solids treatment system 500 can further comprise valves, pumps, motors, actuators, conduit, switches, sensors, and the like. The volume reduction solids treatment system 500 can also comprise a controller 515 (FIG. 16) to operate the valves, pumps, motors, actuators, switches, and sensors. For example, the controller 515 can be connected to a sensor in the pasteurizer 502 to monitor the temperature and control the heater wraps 542 of the pasteurizer 502.

[00177] FIG. 22 illustrates an example method for volume reduction of solids as described herein. At box 1502, the method can include receiving a slurry batch of feces into a pasteurizer. For example, the slurry can be received from a homogenizer or a system comprising a homogenizer, such as a separation and homogenization system. In another example, the slurry can be received into a buffer tank and delivered in batches to the pasteurizer.

[00178] At box 1504, the method can include heating the slurry batch at an elevated temperature for a time period. The time period can be sufficient to kill pathogens producing a pathogen reduced slurry. For example, the temperature of at least 85°C can be maintained for about 10 minutes to kill the pathogens.

[00179] The pathogen reduced slurry can be transferred to a mechanical dewatering press at box 1506. The dewatering press can include a chamber to receive the pathogen reduced slurry and a piston to apply pressure and reduce the volume of the chamber. At box 1508, the method can include compressing the pathogen reduced slurry in the mechanical dewatering press to separate a liquid phase from a volume reduced solid waste. For example, the piston can press the pathogen reduced slurry against a filter to separate the liquid phase from a volume reduced solid waste. At box 1510, the liquid phase can be removed by collecting or directing the liquid to another system. The compression and removal of the liquid can form a feces cake from the volume reduced solid waste at box 1512.

[00180] At box 1514, the method can include ejecting the volume reduced solid waste onto a conveyor. The feces cake or cake formed from the reduced solid waste can be wet and/or sticky. At box 1516, the method can include removing moisture from the volume reduced solid waste to form feces cake. The feces cake can be delivered to a drying tunnel where forced air over the feces cake can further dry the feces cake. At box 1518, the method can include transporting the feces cake to a disposal bin. For example, the cakes can be transported via a belt or conveyor through the drying tunnel over a period of time. [00181] TWO CHAMBER COMBUSTION SYSTEM

[00182] FIGS. 22-27B illustrate a two-chamber combustion system 600 that can be part of or used in conjunction with the volume reduction non-sewered single unit toilet system 10. The two- chamber combustion system 600 can be configured for the combustion of solid waste containing feces. For example, the solid waste can be in the form of feces cakes formed by the volume reduction solids treatment system 500 of the volume reduction non-sewered single unit toilet system 10. The feces cakes can be formed from fecal waste streams comprising feces, as well as urine, water, and other sanitation incidentals contained in a waste stream collected in the volume reduction non-sewered single unit toilet system 10.

[00183] The two-chamber combustion system can comprise first and second chambers with an effective air flow for the evaporative drying and combustion of dried, volume reduced feces cakes, and reduction to ash using biofuel sources to initiate combustion. For example, the biofuel sources can be placed in a first chamber and the dried or partially dried feces cakes can be placed in a second chamber. The biofuel sources can include paper, twigs, wood, and the like. The two- chamber combustion system can be configured work in conjunction with a single-unit toilet system that forms feces cakes as treated solids output. For example, dried or partially dried feces cakes can be produced by a separate feces treatment system, then be transported, by the user, to the two- chamber combustion system to reduce a feces output to inert ash. In some examples, the feces cakes can be transported using a defined disposal bin to the two-chamber combustion system. The two-chamber combustion system is configured to be located on in an exterior location, outside of a house, ideally attached to an external wall for stability. The disposal bin can be designed to selectively interface with the two-chamber combustion system, both to enable clean transport of the cakes to the combustor and to prevent the introduction of other foreign material for burning. In some examples, feces cakes can be transported by other means to the two-chamber combustion system and the disposal bin is not necessary.

[00184] In an example, the two-chamber combustion system can be used for evaporative drying of feces cakes that contain some moisture. The two-chamber combustion system can contain or store the feces cakes without igniting the combustor. In some examples, the feces treatment system can form and partially dry the feces cakes but may require additional drying before combustion. In some examples, the two-chamber combustion system can include a turbine fan on the top of the combustor outlet. The turbine fan can be configured to promote air flow to continue the evaporative drying process of the feces cakes and to prevent potential pathogen regrowth. The two-chamber combustion system can be configured with a height such that the emission of the exhaust is above the heads of most users. For example, the two-chamber combustion system can be at least 8 ft in height. In an example, a non-sewered single unit toilet system can be configured to produce feces cakes, that can be transferred as needed. In some examples, the feces cakes can contain moisture and need to be dried in order to combust. The feces cakes can be temporarily stored in the combustor before the two-chamber combustion system is ignited. For example, the combustor can be lit once a week using biofuel to ignite and bring the feces cake chamber up to temperature for combustion. The two-chamber combustion system can be configured to support both biofuel combustion and feces combustion on separate fuel beds.

[00185] As shown in FIG. 23, the two-chamber combustion system 600 can comprise a combustion section 602, a reduction section 604, an exhaust duct 606, and an exhaust vent 608. The combustion section 602 can include a first chamber 610 and a second chamber 612, which will be described in greater detail herein. The two-chamber combustion system 600 can also include a lower heat shield 638 configured to surround at least a portion of the combustion section 602, and an upper heat shield 640 configured to surround the reducer 618 and at least part of the exhaust duct 606. In some examples, there can be a ventilation gap 642 between the exhaust duct 606 and the top of the upper heat shield 640.

[00186] The two-chamber combustion system 600 can comprise a heat retention insert 650 configured to be positioned within a containment wall 622 of the combustion section 602 and rest on the first plate 630 of the two-chamber combustion system 600 to partially define a first chamber 610 and a second chamber 612. The first chamber 610 can be positioned below the second chamber 612. The first chamber 610 can be configured to burn biofuel at a higher temperature to ignite the feces cakes in the second chamber 612. For example, for example biofuel sources can include paper, twigs, wood, and the like. The first chamber 610, also called a lower chamber herein, can be configured to support a temperature of about 900°C or more for wood combustion. An elevated fuel grate 628 can be positioned on the first plate 630 within the first chamber 610 to elevate the biofuel sources and facilitate burning of the biofuel sources and allow inert ash to collect on the first plate 630. The second chamber 612, also called an upper chamber herein, can be configured to support a temperature of about 375°C for feces combustion. In some examples, the second chamber 612 can be accessed via a door 614 to place feces cakes inside the second chamber 612.

[00187] In an example, the exhaust duct 606 can be a stove pipe or conduit formed in one piece. In another example, the exhaust duct 606 can be provided as one or more sections of stove pipe to vary the length of the exhaust duct 606, thus the height of the two-chamber combustion system 600. For example, the total height of the two-chamber combustion system 600 can be configured based on guidance from local regulations regarding the exhaust or emissions. In an example, the total height of the two-chamber combustion system 600 can be over 8 feet tall. In an example, the exhaust vent 608 can be a turbine ventilator 620 secured to the exhaust duct 606 at an end opposite the combustion section 602 and at a top of the two-chamber combustion system 600. In some examples, the turbine ventilator 620 can be configured to passively dry the feces cakes containing moisture continually, without igniting fuel in either the first or second chamber 610, 612. Further, in some examples, the two-chamber combustion system 600 can have a plurality of adjustable feet 632 configured to level the two-chamber combustion system 600.

[00188] FIG. 24 illustrates a cross-section view of the two-chamber combustion system 600 of FIG. 23. The combustion section 602 can be substantially cylindrical and comprise a containment wall 622 and a heat retention insert 650 configured to fit within the containment wall 622. In some examples, the combustion section 602 also includes a lower heat shield 638 which at least partially surrounds the containment wall 622. The reduction section 604 can comprise the reducer 618 and the exhaust duct 606. In some examples, the combustion section 602 also includes an upper heat shield 640 which at least partially surrounds the reducer 618 and a portion of the exhaust duct 606.

[00189] As shown in FIG. 24, the main combustor body 616 comprises a containment wall 622, reducer 618, and exhaust duct 606. The containment wall 622 can be substantially cylindrical having a first diameter (di) or first cross-section. The exhaust duct 606 can be an elongated cylindrical pipe having a second diameter (d2) or second cross-section, where the first diameter is greater than the second diameter. The reducer 618 can connect the containment wall 622 to the exhaust duct 606. The reducer 618 can be configured to direct the exhaust from the first and second chambers 610, 612 through the exhaust duct 606 for release via the exhaust vent 608. In some examples, the reducer 618 can be at least one reducer or comprise a plurality of reducers.

[00190] The first chamber 610 can be positioned below the second chamber 612. The first and second chambers 610, 612 can be at least partially defined by the heat retention insert 650 configured to fit within the containment wall 622. The heat retention insert 650 can comprise a tubular body 652, a chamber grate 656, tapered flow collar 654, the interior collar 658, first insert collar 660, and second insert collar 662. The first chamber 610 can comprise a volume defined by the first plate 630 and the portion of the heat retention insert 650 within tubular body 652, tapered flow collar 654, and chamber grate 656. The first chamber 610 can also include the volume for air intake between the tubular body 652 and the containment wall 622 and the first insert collar 660. The second chamber 612 can include the volume above chamber grate 656 and within the containment wall 622 including the portion of the heat retention insert 650 within tubular body 652, chamber grate 656, and interior collar 658.

[00191] The first chamber 610 can be configured to burn biofuel at a higher temperature to ignite the feces cakes in the second chamber 612. The second chamber 612 can be accessed via a door 614 in the combustion section 602. In some examples, the two-chamber combustion system 600 can include a rail system 648 configured to receive a solids disposal bin (not shown) containing feces cakes. The solids disposal bin and rail system are configured to reduce direct user contact with the feces cakes. For example, the feces cakes can be deposited directly into the solids disposal bin as they are formed by a feces treatment system. Then, a user can manually move the solids disposal bin containing the feces cakes to the two-chamber combustion system 600 and deposit the feces cakes into the second chamber 612 without the user handling the feces cakes directly. The bin can be removed after the feces cakes have been deposited.

[00192] The heat shields 638, 640 partially surround the main combustor body 616 and act as a thermal barrier to protect external objects from high heat. The upper heat shield 640 can be positioned with a ventilation gap 642 at one end of the reduction section 604 at the exhaust duct 606. As shown in FIG. 24, the heat shields 638, 640 can be positioned with a gap between the main combustor body 616 and the heat shields 638, 640.

[00193] FIGS. 25A-25C show disassembled portion of the combustion section 602 of FIG. 1 in greater detail. The combustion section 602 can comprise a heat retention insert 650 configured to rest on the first plate 630 which defines the floor of a first chamber 610. The heat retention insert 650 also configured to fit within the containment wall 622. The first plate 630 can be a solid plate to eliminate air flow through the first plate 630 and provide a base for the heat retention insert 650. A first plate 630 configured with adjustable feet 632 can be the base for the combustion section 602 and the two-chamber combustion system 600. An elevated fuel grate 628 can be used to lift the wood or biofuel off the solid first plate 630 to increase the surface area of wood exposed to flame. In some examples, the combustion section 602 also includes a lower heat shield 638 which at least partially surrounds the containment wall 622.

[00194] As shown in FIG. 25A, the two-chamber combustion system 600 can comprise a heat retention insert 650 configured to be positioned within a containment wall 622 of the combustion section 602 and rest on the first plate 630 of the two-chamber combustion system 600 to partially define a first chamber 610 and a second chamber 612. Shown also in FIGS. 25A-26B, the heat retention insert 650 comprises a tubular body 652, a chamber grate 656, tapered flow collar 654, the interior collar 658, first insert collar 660, and second insert collar 662. The tapered flow collar 654 and the interior collar 658 can be positioned below and above the chamber grate 656, to further define the first and second chambers 610, 612, respectively. The heat retention insert 650 can be configured with an opening 668 to allow access the first chamber 610. The heat retention insert 650 can have a plurality of air intake openings 664 at a level configured to allow air into the first chamber 610. Similarly, the heat retention insert 650 can have a plurality of air intake openings 665 at one or more levels configured to allow air into the second chamber 612. The first insert collar 660 and the second insert collar 662 can be positioned on an external surface of the tubular body 652 to further control the air intake. The heat retention insert 650 can be configured to fit within the containment wall 622. The first and second insert collars 660, 662 configured to direct airflow and to position the heat retention insert 650 within the containment wall 622 of the combustion section 602. The first and second insert collars 660, 662 can be configured to provide a snug fit against the interior surface of containment wall 622 and to direct airflow through a plurality of slots in the containment wall 622 to the second chamber 612 of the combustion section 602. An elevated fuel grate 628 can be inserted within the first chamber 610 to support the biofuel.

[00195] FIG. 25B illustrates an example containment wall 622 of the combustion section 602. The containment wall 622 can be substantially cylindrical and extend to contain both first and second chambers 610, 612. The containment wall 622 can have a plurality of slots 636 that can be arranged at an intake height (hi) corresponding to the second chamber 612. The plurality of slots 636 can be configured with slots of uniform size or alternate with larger and smaller slots to regulate the air intake to the second chamber 612. When positioned to surround the heat retention insert 650, the containment wall 622 rests on the first plate 630 and/or the adjustable feet 632. The containment wall can be secured to the adjustable feet 632 to maintain the position of the containment wall 622. The opening 668 of the heat retention insert 650 and the first access opening 624 of the containment wall 622 are configured to align so that the biofuel can be added and positioned in the first chamber 610. The first insert collar 660 is configured to have a snug fit within the containment wall 622 such that the plurality of slots 636 are positioned above the perimeter where the first insert collar 660 meets the interior of the containment wall 622, directing air intake to the second chamber 612 and not the first chamber 610.

[00196] The containment wall 622 can be a combustion drum or a tubular section having an exterior surface, an interior surface, and a first diameter di. For example, the containment wall 622 can be made of a high temperature material configured to contain a combustion temperature of about 900°C. For example, the containment wall 622 can comprise carbon steel, iron- chromium-aluminum, or other high-temperature material, high-temperature metal, high- temperature alloy, and the like. In some examples, carbon steel having a melting temperature of 6426°C can be used for the containment wall with safe operation. In an example, the containment wall 622 of the combustion drum be made of 18-gauge steel and can have a thickness of about 0.046 inches thick. The combustion section 602 comprises a first access opening 624 in the containment wall 622 configured for access to the first chamber 610 and a second access opening 626 in the containment wall 622 configured for access to the second chamber 612.

[00197] In an example, the combustion drum can have a containment wall 622 about 32 inches high and about 12 inches in diameter. When the heat retention insert 650 is positioned within the containment wall 622, the first chamber 610 can be defined within the containment wall 622 between the first plate 630 and the chamber grate 656. The biofuel can be loaded in the first chamber 610 via the first access opening 624. In an example, the second chamber 612 can be defined as the volume above the chamber grate 656 defined within the containment wall 622. The feces cake can be deposited in the second chamber 612 via the second access opening 626. The second access opening 626 can be closed by a door (FIG. 23). In some examples, the door 614 can be configured to receive a transfer bin containing feces cakes from a single-unit non-sewered toilet system. In an example, the door 614 can be a hinged door. The second chamber 612 is configured to receive the feces cakes in a portion below the second access opening 626 and into the upper portion of the heat retention insert 650. In an example, the second access opening 626 can be positioned about 12 inches from the chamber grate 656. The second chamber 612 can be configured to hold at least 9250 cc of feces. [00198] The containment wall 622 can also comprise a plurality of slots. For example, as shown in FIG. 25B, a plurality of slots 636 can be arranged at a first intake height positioned above the first height hi of the first plate 630 to provide air intake to the second chamber 612. In some examples, additional slots can be configured to provide air intake to the first chamber. The plurality of slots 636 can be sized, shaped, and distributed as needed for the predetermined air intake for the respective chamber. For example, the plurality of slots can be elongated and evenly distributed about the circumference of the containment wall 622. In some examples, as shown in FIG. 25B, the distribution could vary or have a pattern with larger and smaller slots. In some examples, there could be a second layer of a plurality of slots for the first and/or second chamber. In some examples, the plurality of slots could be closed off or the containment wall formed without slots. In an example, the exhaust vent 608 can comprise a turbine ventilator 620 that can draw air upward through the plurality of slots 636 to promote air flow to continue the evaporative drying process of the feces cakes and to prevent potential pathogen regrowth. Eliminating the air flow through the first plate 630 and portion of the containment wall 622 of the first chamber 610 can increase draft velocity through the first chamber 610 causing an increase in thermal energy delivery to the specimen being dried in the second chamber 612. The plurality of slots 636 can also help provide enough air intake to support full combustion. For example, an air intake greater than 75 g/s can be needed.

[00199] Shown in FIG. 25C, the combustion section 602 can also comprise a lower heat shield 638 to impede direct contact with the exterior surface of the containment wall 622. The lower heat shield 638 can be configured to surround the containment wall 622 and rest positioned within slots of the adjustable feet 632. The lower heat shield 638 can be substantially cylindrical with first and second access portions 644, 646. The first access portion 644 configured to allow access to the first chamber 610 and the second access portion 646 configured to allow assess to second chamber 612 via the door 614 of the containment wall 622.

[00200] FIGS. 26A and 26B illustrate a front view and cross-sectional view of the heat retention insert 650. The heat retention insert 650 can comprise a tubular body 652, a plurality of air intake openings 664, 665, and a chamber grate 656. The heat retention insert 650 can also comprise tapered flow collar 654 and the interior collar 658, positioned below and above the chamber grate 656, to further define the first and second chambers 610, 612, respectively. The heat retention insert 650 can also comprise first and second insert collars 660, 662 configured to direct airflow and to position the heat retention insert 650 within the containment wall 622 of the combustion section 602.

[00201] In this example, the heat retention insert 650 can include a chamber grate 656 to partially define the floor of the second chamber 612. The geometry of the heat retention insert 650 can add control of the air flow through the two-chamber combustion system 600 without modifying the containment wall 622. The heat retention insert 650 can focus thermal energy from the first chamber 610, such that more heat is retained in the second chamber 612. The heat retention insert 650 can be configured to more precisely control air flow. The heat retention insert 650 can provide increase thermal efficiency such that less wood, or other biomass, is needed to keep the system at operating temperature and burning.

[00202] In an example, the heat retention insert 650 can comprise a tubular body 652 having a diameter d3 smaller than the first diameter dl of the containment wall 622 and greater than the diameter d2 of the exhaust duct 606. The tubular body 652 can be made of steel or other high temperature metal or material. The heat retention insert 650 can be inserted within the containment wall 622 of the combustion section 602. The heat retention insert 650 can have a height that extends from the first plate 630 of the first chamber 610 to a height just below or about the bottom of the second access opening 626.

[00203] A tapered flow collar 654 can be provided at a first insert height xl of the tubular body 652, extending a reduced cross-section at the bottom of the chamber grate 656. The tapered flow collar 654 and the chamber grate 656 defining the top of the first chamber 610. The tapered flow collar 654 can be configured to direct the air flow to the reduced the cross-sectional area of the perforated floor of the second chamber 612.

[00204] In this embodiment, the heat retention insert 650 can comprise a chamber grate 656 of the second chamber 612 provided within the tubular body 652. For example, the chamber grate 656 can be provided at a first insert height x2 and can have perforations. An interior collar 658 can further define the floor of the second chamber 612. The interior collar 658 tapering from the inside of the tubular body 652 at a third insert height x3 to the chamber grate 656 at the second insert height x2. The slope of the interior collar 658 can help prevent flat feces cakes from fully covering the chamber grate 656. The inner diameter of the interior collar 658 is the same as the reduced diameter of the tapered flow collar 654. [00205] A first insert collar 660 can be positioned between the tubular body 652 and the containment wall 622 and extend in a tapered manner from third insert height x3 to the second insert height x2. The second insert collar 662 can extend outward from the tubular body 652 a tapered manner from a third insert height x4 to inside of the containment wall 622 at a fifth insert height x5, which is the top of the heat retention insert 650. For example, the height of the heat retention insert 650 can be about 17 inches from the bottom to the top.

[00206] The tubular body 652 can have a plurality of holes, slots, or other openings within the wall of the tubular body 652 to allow air flow. For example, as shown in FIG. 26 A, a plurality of air intake openings 664 can be distributed at a predetermined level of the first chamber 610, where the openings are sized for a predetermined air intake to the first chamber 610. Similarly, a plurality of openings 665a, 665b can be distributed at a first and second level of the second chamber 612, where the openings are sized for a selected air intake to the second chamber 612. For example, each level containing the plurality of openings can be sized, shaped, and distributed as needed for the predetermined air intake for the respective chamber.

[00207] Shown in FIGS. 27A and 27B, the chamber grate 656, tapered flow collar 654, and the interior collar 658 of the heat retention insert 650 are shown in greater detail. The chamber grate 656 can define in part the division between the first chamber 610 and the second chamber 612. The tapered flow collar 654 can be shaped to direct the heat from the first chamber 610 to the bottom of the chamber grate 656 to combust the feces cakes collected in the second chamber 612. The heat retention insert 650 can include radial ribs 670 extending from the interior collar 658 to the chamber grate 656 within the second chamber 612 portion of the heat retention insert 650. The radial ribs 670 in combination with the interior collar 658 help guide the deposited feces cakes toward the chamber grate 656 of the second chamber 612 for better combustion.

[00208] In some examples, the two-chamber combustion system can be configured to work in conjunction with a stand-alone non-sewer sanitation system that forms feces cakes as treated solids output. The two-chamber combustion system can be configured to receive a transport bin that interfaces with a stand-alone non-sewer sanitation system that produces feces. The transport bin can be configured to allow transport of the feces cakes without the user being in direct contact with the feces cakes.

[00209] The features of the embodiments described herein are representative and, in alternative embodiments, certain features and elements can be added or omitted. It is to be understood that, unless otherwise indicated, the present disclosure is not limited to particular materials, manufacturing processes, or the like, as such can vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only and is not intended to be limiting. It is also possible in the present disclosure that steps can be executed in different sequence where this is logically possible.

[00210] ASPECTS

[00211] The following list of exemplary aspects supports and is supported by the disclosure provided herein.

[00212] Aspect 1. A non-sewered toilet system, comprising: a frontend separation system comprising a solids separator, the frontend separation system configured to receive a combined waste and separate the combined waste into a separated solids portion and a separated liquid portion and the separated solids portion comprising mostly solids and some fluid and the separated liquid portion comprising mostly fluid with some solids, the combined waste comprising at least one of urine and feces; a buffer tank separation system comprising: a liquids collection tank, a solids collection tank, and a belt separator, the belt separator positioned to receive an input stream comprising at least one of: the separated solids portion and the separated liquids portion from the frontend separation system, the belt separator configured further separate the input stream to deliver a solids portion of the input stream to the solids collection tank and to deliver the liquids portion of the input stream to the liquids collection tank; a liquid waste treatment system configured to receive liquid waste collected in the liquids collection tank of the buffer tank separation system, comprising: an ultra-filtration stage comprising an ultra-filtration filter configured to separate the liquid waste into a first permeate and a first concentrate, and a reverse osmosis stage configured to receive a first permeate from the ultra-filtration stage and separate the first permeate into a second permeate and a second concentrate, the second permeate being a useable water; and a solids waste treatment system configured to receive a feces slurry from the buffer tank separation system, the feces slurry comprising the solids waste collected in the solids collection tank, comprising: a pasteurizer configured to receive a slurry batch and heat the slurry batch at an elevated temperature for a time period to produce a pathogen free slurry; a mechanical dewatering press configured to compress the pathogen free slurry to separate a liquid phase from a volume reduced solid waste, the volume reduced solid waste being formed into a feces cake; and a drying tunnel.

[00213] Aspect 2. The non-sewered toilet system of aspect 1, wherein at least the solids separator, the buffer tank separation system, the liquid waste treatment system, and the solids waste treatment system are housed in a single unit.

[00214] Aspect 3. The non-sewered toilet system of aspect 1 or 2, wherein the buffer tank separation system further comprises a homogenizer connected to a solids outlet of the solids collection tank, the homogenizer configured to receive the collected solids portion and form the feces slurry, the feces slurry being a uniform and homogenized slurry.

[00215] Aspect 4. The non-sewered toilet system of any one of aspects 1-3, wherein the ultra filtration stage comprises an ultra-filtration membrane filter, a first retention tank, and a first pump.

[00216] Aspect 5. The non-sewered toilet system of aspect 4, wherein the ultra-filtration stage is configured to deliver the first concentrate to the buffer tank separation system, the first concentrate comprising fluid rejected by the ultra-filtration filter.

[00217] Aspect 6. The non-sewered toilet system of any one of aspects 1-5, wherein the reverse osmosis stage comprises a reverse osmosis filter, a second retention tank, and a second pump.

[00218] Aspect 7. The non-sewered toilet system of aspect 6, wherein the reverse osmosis stage is configured to deliver a second concentrate to the second retention tank.

[00219] Aspect 8. The non-sewered toilet system of aspect any one of aspects 1-7, further comprising a concentrator configured to receive a concentrate from the liquid waste treatment system and reduce the concentrate by heating and evaporation, forming a condensed effluent, the concentrate comprising fluid rejected by the reverse osmosis filter.

[00220] Aspect 9. The non-sewered toilet system of aspect 8, wherein the condensed effluent is delivered to the drying tunnel or a portion of the condensed effluent is delivered to the buffer tank separation system or both. [00221] Aspect 10. The non-sewered toilet system of any one of aspects 1-9, wherein at least a portion of the useable water produced by the liquid waste treatment system is used as flush water.

[00222] Aspect 11. The non-sewered toilet system of any one of aspects 1-10, wherein the solids waste treatment system is configured to deliver the liquid phase separated from the volume reduced solid waste to the buffer tank separation system.

[00223] Aspect 12. The non-sewered toilet system of any one of aspects 1-11, wherein the pasteurizer of the solids waste treatment system comprises one or more heaters.

[00224] Aspect 13. The non-sewered toilet system of any one of aspects 1-12, wherein a controller enables automated operation of at least one of: the frontend separation system, the buffer tank separation system, the liquid waste treatment system, and the solids waste treatment system.

[00225] Aspect 14. The non-sewered toilet system of any one of aspects 1-13, further comprising a combustor configured to receive one or more feces cakes and reduce the one or more feces cakes to ash.

[00226] Aspect 15. The non-sewered toilet system of aspect 14, wherein the combustor is configured to passively dry the one or more feces cakes.

[00227] Aspect 16. The non-sewered toilet system of any one of aspects 1-15, wherein the solids separator comprises: a vacuum tank having a top portion, a base, and a cylindrical wall, the vacuum tank, comprising: an inlet chamber formed within the vacuum tank at the top portion, the inlet chamber comprising an inlet and a chamber outlet; a solids containment portion formed in the base of the vacuum tank and positioned centrally within the vacuum tank, the solids containment portion comprising a solids outlet, the solids containment portion configured to hold a separated solids portion of the combined waste; a liquid containment portion formed in the base of the vacuum tank and contained within the vacuum tank surrounding the solids containment portion, the liquid containment portion comprising a liquids outlet, the liquid containment portion configured to hold a separated liquid portion of the combined waste portion; a separating filter having a cylindrical tubular shape and extending from the chamber outlet to the solids containment portion, the separating filter forming a central separation volume within the vacuum tank; and wherein the inlet chamber is configured to receive the combined waste via an inlet such that the combined waste is guided in a spiral about an interior surface of the inlet chamber and directed to the central separation volume, the liquid portion of the combined waste being allowed to flow through the separating filter to an outer portion surrounding the central separation volume and collect in the liquid containment portion of the base, the solids portion of the combined waste contained within the central separation volume and collected in the solids containment portion of the base.

[00228] Aspect 17. The non-sewered toilet system of aspect 16, wherein, in the solids separator, the separating filter comprises a plurality of profile wires, each of the profile wires having a specified cross-section, the plurality of profile wires are arranged at a regular interval to form a plurality of grooves extending from slits between the profile wires at an inner circumference of the cylindrical tubular shape to wider openings at an outer circumference of the cylindrical tubular shape.

[00229] Aspect 18. The non-sewered toilet system of aspect 16 or 17, wherein, in the solids separator, the base of the vacuum tank has an inclined base within the liquid containment portion such that a flow of the liquid portion of the combined waste collected in the liquid containment portion of the base is directed to the liquids outlet.

[00230] Aspect 19. The non-sewered toilet system of any one of aspects 16-18, wherein, in the solids separator, the solids containment portion is funnel or conical shaped to direct the solids portion of the combined waste to the solids outlet.

[00231] Aspect 20. The non-sewered toilet system of any one of aspects 16-19, wherein, in the solids separator, the solids portion of the combined waste collected in the solids containment portion is released via the solids outlet after a pressure is applied to the vacuum tank.

[00232] Aspect 21. The non-sewered toilet system of any one of aspects 16-20, wherein, in the solids separator, the liquid portion of the combined waste collected in the liquid containment portion is released via the liquids outlet by gravity.

[00233] Aspect 22. The non-sewered toilet system of any one of aspects 16-21, wherein the solids separator further comprises a first actuator configured to operate a first valve at the solids outlet and a second actuator configured to operate a second valve the liquids outlet. [00234] Aspect 23. The non-sewered toilet system of aspect 22, wherein, in the solids separator, the first valve is configured to open when an overpressure is applied to the vacuum tank, releasing the solids portion of the combined waste collected in the solids containment portion.

[00235] Aspect 24. The non-sewered toilet system of aspect 22 or 23, wherein, in the solids separator, the second valve is actuated after the first valve, releasing the liquid portion of the combined waste collected in the liquid containment portion.

[00236] Aspect 25. The non-sewered toilet system of any one of aspects 1-24, wherein the frontend system further comprises a vessel configured to receive at least urine and feces and a flush tank configured to deliver a volume of flush water to the vessel to form a combined waste within the vessel.

[00237] Aspect 26. The non-sewered toilet system of aspect 25, wherein a vacuum is applied to vacuum tank of the solids separator by a vacuum pump to evacuate the vessel.

[00238] Aspect 27. The non-sewered toilet system of aspect 25 or 26, further comprising a user interface configured for a user to select a flush mode comprising at least one of: a urine event mode and a defecation event mode.

[00239] Aspect 28. The non-sewered toilet system of any one of aspects 1-27, wherein the buffer tank separation system further comprises at least one inlet configured to receive an input stream.

[00240] Aspect 29. The non-sewered toilet system of aspect 28, wherein the belt separator of the buffer tank separation system comprises a perforated belt looped between two rollers, the belt separator positioned to receive the input stream via the at least one inlet onto the perforated belt of the belt separator.

[00241] Aspect 30. The non-sewered toilet system of aspect 29, wherein the perforated belt of the belt separator comprises pores configured to allow the liquids portion of the input stream to pass through to the liquids collection tank and to retain the solids portion on the perforated belt.

[00242] Aspect 31. The non-sewered toilet system of aspect 29 or 30, wherein the buffer tank separation system further comprises a squeegee configured to remove the solids portion of the input stream from the perforated belt of the belt separator.

[00243] Aspect 32. The non-sewered toilet system of any one of aspects 1-31 wherein the buffer tank separation system further comprises a liquid deflector positioned beneath the belt separator configured to direct at least some of the liquids portion of the input stream to the liquids collection tank.

[00244] Aspect 33. The non-sewered toilet system of any one of aspects 1-32, wherein the liquids collection tank of the buffer tank separation system further comprises a sludge outlet and a bottom wall configured to direct a sludge stream to the sludge outlet, the sludge stream comprising solids settled from the liquids portion contained in the liquids collection tank.

[00245] Aspect 34. The non-sewered toilet system of any one of aspects 1-33, wherein the solids collection tank of the buffer tank separation system further comprises an overflow outlet.

[00246] Aspect 35. The non-sewered toilet system of any one of aspects 28-34, wherein, in the buffer tank separation system, the at least one inlet comprises a solids inlet configured to receive a mostly solids input stream comprising feces, the solids inlet comprising a chamber, an offset chamber inlet, and a chamber outlet, the chamber shaped such that the solids input stream received via the offset chamber inlet is directed toward an interior wall surface of the chamber to flow out the chamber outlet onto the belt separator.

[00247] Aspect 36. The non-sewered toilet system of any one of aspects 28-35, wherein, in the buffer tank separation system, the at least one inlet comprises a liquids inlet configured to receive and direct a mostly liquids input stream onto the belt separator.

[00248] Aspect 37. The non-sewered toilet system of any one of aspects 28-36, wherein, in the buffer tank separation system, the at least one inlet comprises one or more auxiliary input ports configured to receive at least one of: a urine stream comprising mostly urine, a sludge stream received from the liquids collection tank, an overflow stream received from the solids collection tank, a reject stream received from a liquids treatment system, a filtrate received from a feces treatment system, and a condensed effluent received from a feces treatment system.

[00249] Aspect 38. The non-sewered toilet system of any one of aspects 29-37, wherein the buffer tank separation system further comprises a motor configured to drive at least one of the two rollers of the belt separator.

[00250] Aspect 39. The non-sewered toilet system of any one of aspects 1-38, wherein the liquid waste treatment system further comprises a diffuser positioned at an inlet to the ultra- filtration filter, the diffuser connected to an air blower and configured to introduce air into the liquid waste to reduce the density of the liquid waste and to generate a crossflow within the ultra- filtration filter. [00251] Aspect 40. The non-sewered toilet system of any one of aspects 1-39, wherein the ultra-filtration stage of the liquid waste treatment system comprises a first pump configured to deliver the first permeate to a first retention tank.

[00252] Aspect 41. The non-sewered toilet system of any one of aspects 1-40, the reverse osmosis stage of the liquid waste treatment system comprises a second pump configured to deliver the second permeate to a second retention tank.

[00253] Aspect 42. The non-sewered toilet system of aspect 41, wherein the second pump is configured to operate at a high pressure.

[00254] Aspect 43. The non-sewered toilet system of aspect 41 or 42, wherein the second pump is configured to operate at a pressure of about 30 to 35 bar.

[00255] Aspect 44. The non-sewered toilet system of any one of aspects 1-43, wherein the second permeate discharged as the useable water is a non-potable water for use or re-use from the liquid waste treatment system meets at least one of: chemical oxygen demand (COD) < 50 mg/L; total suspended solids (TSS) < 10 mg/L; total Nitrogen (N) > 70% reduction relative to the total N in the liquid waste received into the UF stage; total Phosphorus (P) > 80% reduction relative to the total P in the liquid waste received into the UF stage; and

E. coli < 100 per L.

[00256] Aspect 45. The non-sewered toilet system of any one of aspects 1-44, wherein, in the liquid waste treatment system, the ultra-filtration stage operates at a first pressure and the reverse osmosis stages operate at a second pressure.

[00257] Aspect 46. The non-sewered toilet system of aspect 45, wherein, in the liquid waste treatment system, the reverse osmosis stage operates at a high pressure.

[00258] Aspect 47. The non-sewered toilet system of any one of aspects 39-46, wherein, in the liquid waste treatment system, the diffuser comprises an air stone.

[00259] Aspect 48. The non-sewered toilet system of any one of aspects 39-47, wherein, in the liquid waste treatment system, a controller enables automated operation of the ultra-filtration stage and the reverse osmosis stage. [00260] Aspect 49. The non-sewered toilet system of any one of aspects 1-48, wherein drying tunnel of the solids waste treatment system comprises a conveyor housed in an air duct system, the air duct system configured to propel forced air over the feces cake in the drying tunnel.

[00261] Aspect 50. The non-sewered toilet system of any one of aspects 1-49, wherein the pasteurizer of the solids waste treatment system comprises a length of tubing and one or more heaters configured to heat the slurry batch within the tubing.

[00262] Aspect 51. The non-sewered toilet system of aspect 50, wherein the one or more heaters comprises a plurality of heaters having independent temperature control, each heater of the plurality of heaters wrapped around the length of tubing defining a heating zone for a section of tubing.

[00263] Aspect 52. The non-sewered toilet system of any one of aspects 1-51, wherein the mechanical dewatering press of the solids waste treatment system comprises a filter assembly, a chamber, and a piston.

[00264] Aspect 53. The non-sewered toilet system of aspect 52, wherein the mechanical dewatering press further comprises a filtrate outlet and a squeegee, wherein the squeegee is configured to remove the feces cake from the mechanical dewatering press.

[00265] Aspect 54. The non-sewered toilet system of aspect 52 or 53, wherein the filter assembly of the mechanical dewatering press comprises a filter screen.

[00266] Aspect 55. The non-sewered toilet system of aspect 54, wherein the filter screen is a nylon net or stainless-steel mesh.

[00267] Aspect 56. The non-sewered toilet system of any one of aspects 49-55, wherein, in the solids waste treatment system, the drying tunnel dries the feces cake to a moisture content of 4- 10%.

[00268] Aspect 57. The non-sewered toilet system of any one of aspects 49-56, wherein the solids waste treatment system further comprises a disposal bin configured to receive and collect a batch of feces cakes.

[00269] Aspect 58. The non-sewered toilet system of any one of aspects 14-57, wherein the combustor comprises: a combustion section comprising a cylindrical wall, a first combustion chamber, and a second combustion chamber, the first combustion chamber positioned beneath the second combustion chamber and configured to receive a first fuel, the second combustion chamber configured to receive a second fuel, the second fuel comprising feces; an exhaust duct; a reducer configured to connect the combustion section to the exhaust duct; and an exhaust vent connected to the exhaust duct at an end opposite the combustion section and at a top of the combustor.

[00270] Aspect 59. The non-sewered toilet system of aspect 58, wherein the combustor further comprises a first plurality of slots in the cylindrical wall at a first intake height.

[00271] Aspect 60. The non-sewered toilet system of aspect 59, wherein, in the combustor the first plurality of slots is configured to provide airflow to the second chamber.

[00272] Aspect 61. The non-sewered toilet system of any one of aspects 58-60, wherein the combustor further comprises a first access opening in the cylindrical wall to the first chamber and a second access opening in the cylindrical wall to the second chamber.

[00273] Aspect 62. The non-sewered toilet system of aspect 61, wherein the combustor further comprises a door to close the second access opening.

[00274] Aspect 63. The non-sewered toilet system of any one of aspects 59-62, wherein, in the combustor, the exhaust vent comprises a turbine ventilator.

[00275] Aspect 64. The non-sewered toilet system of aspect 63, wherein, in the combustor the turbine ventilator is configured to rotate to draw air from the combustion section to continually passively dry the feces cakes.

[00276] Aspect 65. The non-sewered toilet system of any one of aspects 59-64, wherein the combustor further comprises: a first plate defining a floor of a first chamber and secured to the cylindrical wall; and a heat retention insert configured to fit within the cylindrical wall, the heat retention insert comprising: a tubular body comprising a plurality of air intake openings; and a chamber grate positioned at a second height within the tubular body to at least partially define a floor of the second chamber.

[00277] Aspect 66. The non-sewered toilet system of aspect 65, wherein the combustor further comprises a tapered flow collar and an interior collar, the tapered flow collar positioned at a height within the tubular body below the chamber grate and extending to a reduced cross-section of the chamber grate, the interior collar positioned at a height within the tubular body above the chamber grate and extending to the reduced cross-section of the chamber grate.

[00278] Aspect 67. The non-sewered toilet system of aspect 65 or 66, wherein the combustor further comprises first and second insert collars positioned on an external surface of the tubular body, the first and second insert collars configured to provide a snug fit against the cylindrical wall.

[00279] Aspect 68. The non-sewered toilet system of aspect 67, wherein, in the combustor, the first insert collar is positioned at the height of the interior collar and extends outward to contact the cylindrical wall.

[00280] Aspect 69. The non-sewered toilet system of aspect 67 or 68, wherein, in the combustor, the second insert collar is positioned at the top of the tubular body and extends outward to contact the cylindrical wall at a height at or below an access opening to the second chamber.

[00281] Aspect 70. The non-sewered toilet system of any one of aspects 67-69, wherein, in the combustor, a first set of openings of the plurality of openings are distributed at a height to provide airflow to the first chamber and a second set of openings of the plurality of openings are distributed at a height to provide airflow to the second chamber.

[00282] Aspect 71. The non-sewered toilet system of any one of aspects 58-70, wherein, in the combustor, the first chamber further comprises an elevated fuel grate configured to lift the first fuel.

[00283] Aspect 72. The non-sewered toilet system of any one of aspects 58-71, wherein, in the combustor, the combustion section is configured to support a temperature of at least 900°C in the first chamber.

[00284] Aspect 73. The non-sewered toilet system of any one of aspects 58-72, wherein, in the combustor, the second chamber is configured to support a temperature of at least 375°C.

[00285] Aspect 74. The non-sewered toilet system of any one of aspects 58-73, wherein, in the combustor, the second chamber is configured to hold at least 9250cc of volume of feces cakes.

[00286] Aspect 75. A method for treatment of human waste, the method comprising: receiving, into a frontend separation system, a human waste comprising at least one of urine and feces; separating the human waste into at least one of a mostly liquid stream and a mostly solids stream; delivering the mostly liquid stream from the frontend separation system to a buffer tank separation system; receiving the mostly liquid stream via a first inlet onto a belt separator and separating at least some of the solids from the mostly liquid stream; depositing the solids separated from the mostly liquid stream into a solids collection tank and depositing a remaining portion of the mostly liquid stream into a liquids collection tank for short-term storage and passive separation of liquid from remaining solid waste received into the liquids collection tank; delivering the mostly solids stream from the frontend separation system to the buffer tank separation system; receiving the mostly solids stream via a second inlet onto the belt separator and separating most of the solids from the mostly solids stream; depositing the solids separated from the mostly solids stream into the solids collection tank and deposit a remaining portion of the mostly solids stream into the liquids collection tank for short-term storage and passive separation of liquid from remaining solid waste received into the liquids collection tank; separating pathogens from a liquid waste received from a volume of collected liquids separated within the liquids collection tank in a urine and wastewater treatment system; delivering a volume of collected solids settled within the solids collection tank to a homogenizer to form a feces slurry; inactivating pathogens in the feces slurry in a volume reduction solids treatment system and forming feces cakes by removing moisture from the pathogen free slurry.

[00287] Aspect 76. The method of aspect 75, wherein the mostly liquid stream is less than 5% dry solids content by volume and the mostly solids stream is about 1% to about 25% dry solid contents by volume.

[00288] Aspect 77. The method of aspect 75 or 76, further comprising: receiving a liquid waste comprising the volume of collected liquids separated within the liquids collection tank to a urine and wastewater treatment system; blowing air into the liquid waste to reduce the density of the liquid waste and to generate crossflow; filtering the liquid waste in an ultra-filtration stage to separate a first permeate and a first concentrate; discharging the first concentrate to the buffer tank separation system; filtering the first permeate in a reverse osmosis stage to separate a second permeate and a second concentrate; recirculating the second concentrate to filter in reverse osmosis stage; and discharging the second permeate as useable water.

[00289] Aspect 78. The method of aspect 77, wherein the second permeate discharged as useable water meets at least one of: chemical oxygen demand (COD) < 50; total suspended solids (TSS) < 10 mg/L; total Nitrogen (N) > 70% reduction relative to the total N of the liquid waste received into the ultra-filtration stage; total Phosphorus (P) > 80% reduction relative to the total P of the liquid waste received into the ultra-filtration stage; and E. coli < 100 per L.

[00290] Aspect 79. The method of aspect 77 or 78, further comprising: delivering a volume of the second concentrate to a concentrator; and heating the volume of the second concentrate forming a condensed effluent by evaporation.

[00291] Aspect 80. The method of any one of aspects 77-79, wherein the reverse osmosis stage operates at a high pressure.

[00292] Aspect 81. The method of any one of aspects 75-80, further comprising: receiving, into a pasteurizer, a slurry batch comprising the feces slurry; heating the slurry batch at an elevated temperature for a time period, the time period sufficient to kill pathogens producing a pathogen reduced slurry; transferring the pathogen reduced slurry to a mechanical dewatering press; compressing the pathogen reduced slurry in the mechanical dewatering press to separate a liquid phase from a volume reduced solid waste; removing the liquid phase; forming a feces cake from the volume reduced solid waste; ejecting the feces cake onto a conveyor; and removing moisture from the feces cake in a drying tunnel.

[00293] Aspect 82. The method of aspect 81, wherein the volume reduced solid waste is about 20% or less of a volume of the slurry batch.

[00294] Aspect 83. The method of aspect 81 or 82, wherein the elevated temperature is at least 85°C.

[00295] Aspect 84. The method of any one of aspects 81-83, wherein the time period is about 10 minutes.

[00296] Aspect 85. The method of any one of aspects 81-84, wherein the feces cakes are dried to a moisture content of 4-10%.

[00297] Aspect 86. The method of any one of aspects 81-85, wherein the dried feces cakes has an E. coli count <100 per gram.

[00298] Aspect 87. The method of any one of aspects 81-86, further comprising: depositing a batch of feces cakes in an upper chamber of a two-chamber combustor; when the batch of feces cakes contains some moisture, passively and continually drying the batch of feces cakes; igniting biofuel in a lower chamber of the two-chamber combustor, and burning the batch of feces cakes in the upper chamber.

[00299] Aspect 88. The method of aspect 87, wherein a combustion temperature for the biofuel in the lower chamber exceeds 900°C.

[00300] Aspect 89. The method of aspect 87 or 88, wherein a combustion temperature for the feces cakes in the upper chamber exceeds 375°C.

[00301] Aspect 90. The method of any one of aspects 75-89, wherein separating the human waste into at least one of a mostly liquid stream and a mostly solids stream comprises: receiving a human waste into a vessel having a main outlet, the human waste comprising at least one of: urine and feces; receiving a volume of flush water forming a combined waste within the vessel; evacuating the combined waste through a main outlet of the vessel into a solids separator; and separating the combined waste into a liquid portion comprising mostly fluid with some solids and a solids portion comprising mostly solids and some fluid. [00302] Aspect 91. The method of aspect 90, wherein evacuating the combined waste comprises: using a vacuum pump to form a weak vacuum to transport the combined waste to the solids separator.

[00303] Aspect 92. The method of aspect 90 or 91, wherein the combined waste is received into an inlet chamber of the solids separator via the inlet, the inlet being positioned to receive the combined waste tangentially and direct the combined waste along a circumferential interior wall of the inlet chamber to decelerate the combined waste.

[00304] Aspect 93. The method of any one of aspects 90-92, wherein the solids portion of the combined waste collected in the solids containment portion is released via a solids outlet after a pressure is applied to the vacuum tank.

[00305] Aspect 94. The method of any one of aspects 90-93, wherein the liquid portion separated from the combined waste comprises less than 5% dry solids content, the solid content comprising at least one of feces and toilet paper.

[00306] Aspect 95. The method of any one of aspects 90-94, wherein the solids portion separated from the combined waste comprises about l%-25% dry solids content, the solids content comprising at least one of feces and toilet paper.

[00307] Aspect 96. The method of any one of aspects 90-95, wherein the volume of flush water comprises a predetermined amount of flush water based on whether the human waste received is due to a urination event or a defecation event.

[00308] Aspect 97. The method of any one of aspects 75-96, wherein, in the buffer tank separation system, the method comprises: receiving, onto a belt separator, an input stream comprising at least one of: solids and liquids; separating, by the belt separator, the input stream into a solids portion and a liquids portion; delivering the liquids portion to a liquids collection tank for sedimentation; delivering the solids portion to a solids collection tank.

[00309] Aspect 98. The method of aspect 97, wherein the input stream comprises at least one of: a mostly liquids input stream, a mostly solids input stream comprising feces, a urine stream comprising mostly urine, a sludge stream received from the liquids collection tank, an overflow stream received from the solids collection tank, a reject stream received from a liquids treatment system, a filtrate received from a feces treatment system, and a condensed effluent received from a feces treatment system.

[00310] Aspect 99. The method of aspect 98, wherein when the input stream is a mostly solids input stream comprising feces, the input stream is received via a solids inlet comprising a chamber, an offset chamber inlet, and a chamber outlet, the chamber shaped such that the solids input stream received via the offset chamber inlet is directed toward an interior wall surface of the chamber to flow out the chamber outlet onto the belt separator.

[00311] Aspect 100. The method of any one of aspects 97-99, wherein the belt separator comprises a perforated belt looped between two rollers, the belt separator positioned to receive an input stream comprising at least one of: solids and liquids, the input stream received via the at least one inlet onto the belt of the belt separator, the belt separator configured to deliver the solids portion of the input stream to the solids collection tank and to deliver the liquids portion of the input stream to the liquids collection tank.

[00312] Aspect 101. The method of any one of aspects 97-100, wherein the perforated belt of the belt separator comprises pores configured to allow the liquids portion of the input stream to pass through to the liquids collection tank and to retain the solids portion on the perforated belt.

[00313] Aspect 102. The method of any one of aspects 97-101, wherein delivering the solids portion to the solids collection tank comprises removing the solids portion of the input stream from the perforated belt of the belt separator with a squeegee.

[00314] Aspect 103. The method of any one of aspects 97-102, wherein delivering the liquids portion to a liquids collection tank for sedimentation comprises directing at least some of the liquids portion of the input stream to the liquids collection tank via a liquid deflector positioned beneath the belt separator.

[00315] Aspect 104. The method of any one of aspects 97-103, further comprising releasing a collected liquids portion from the liquids collection tank to a liquids treatment system.

[00316] Aspect 105. The method of any one of aspects 97-104, further comprising delivering a sludge portion of the liquids collection tank to the belt separator via a sludge outlet.

[00317] Aspect 106. The method of any one of aspects 97-105, further comprising delivering an overflow portion of the solids collection tank to the belt separator via an overflow outlet. [00318] Aspect 107. The method of any one of aspects 97-106, further comprising forming, in a homogenizer, a uniform and homogenized slurry from a collected solids portion output from the solids collection tank.

[00319] Aspect 108. The method of aspect 107, further comprising releasing the slurry to a feces treatment system.

[00320] Aspect 109. The method of any one of aspects 77-108, further comprising pumping the first permeate to a reservoir tank.

[00321] Aspect 110. The method of aspect 109, further comprising pumping the first permeate from the reservoir tank through the reverse osmosis stage at a high pressure.

[00322] Aspect 111. The method of any one of aspects 77-110, further comprising recirculating the second concentrate to filter in the reverse osmosis stage.

[00323] Aspect 112. The method of any one of aspects 77-111, wherein the liquid waste comprises at least one of urine, feces, rinse water, and trace toilet incidentals.

[00324] Aspect 113. The method of any one of aspects 77-112, wherein the liquid waste is a clarified liquid received from a buffer tank system.

[00325] Aspect 114. The method of any one of aspects 77-113, wherein discharging the first concentrate comprises discharging the first concentrate to a system for separation of solid waste in concentrate.

[00326] Aspect 115. The method of any one of aspects 77-114, wherein filtering the first permeate in the reverse osmosis stage comprises receiving the first permeate in a reservoir tank and recirculating the second concentrate.

[00327] Aspect 116. The method of any one of aspects 81-115, wherein removing moisture from the volume reduced solid waste comprises propelling forced air over the volume reduced solid waste on the conveyor to provide evaporative drying during transport in a drying tunnel.

[00328] Aspect 117. The method of any one of aspects 81-116, wherein the volume reduced solid waste is about 20% or less of a volume of the slurry batch.

[00329] Aspect 118. The method of any one of aspects 81-117, wherein removing the liquid phase comprises transporting the liquid phase to a buffer tank system.

[00330] Aspect 119. The method of any one of aspects 81-118, wherein a volume of the slurry batch is about 100 mL. [00331] Aspect 120. The method of any one of aspects 81-119, wherein the elevated temperature is at least 85°C.

[00332] Aspect 121. The method of any one of aspects 81-120, wherein the time period is about 10 minutes.

[00333] Aspect 122. The method of any one of aspects 81-121, wherein the feces cake is dried to a moisture content of 4-10%.

[00334] Aspect 123. The method of any one of aspects 81-122, wherein the dried feces cake has an E. coli count <100 per gram.

[00335] Aspect 124. The method of any one of aspects 81-123, further comprising transporting the feces cake to a disposal bin.

[00336] Aspect 125. The method of any one of aspects 87-124, wherein depositing the batch of feces cakes further comprises inserting a disposal bin from a volume reduction solids treatment system into a receiving interface, the disposal bin containing the batch of feces cakes.

[00337] The features of the embodiments described herein are representative and, in alternative embodiments, certain features and elements can be added or omitted. It is to be understood that, unless otherwise indicated, the present disclosure is not limited to particular materials, manufacturing processes, or the like, as such can vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only and is not intended to be limiting. It is also possible in the present disclosure that example methods can omit steps or include additional steps or can be executed in different sequence where this is logically possible.

[00338] EXAMPLES

[00339] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and/or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the disclosure and are not intended to limit the scope of what the inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. [00340] Samples of the liquid output of the urine and wastewater treatment system were tested to measure chemical oxygen demand (COD), total nitrogen (total N), total phosphorus (total P), pH, total suspended solids (TSS), and E. coli (colony forming units or CFUs). Examples of tested liquid output parameters compared to the ISO 30500 standard are shown in TABLE 1. Exemplary methods for testing the liquid output parameters are provided in the Test Protocols below.

TABLE 1. _

[00341] TEST PROTOCOLS

[00342] Chemical Oxygen Demand Test Protocol: The chemical oxygen demand (COD) is measured for samples taken using the Urine and Wastewater Treatment System Sampling Procedure as described herein. Chemical oxygen demand can be measured by any method known in the art such as, for example, using a USEPA Reactor Digestion Method kit manufactured by HACH® Company (Loveland, CO, USA). Spectrophotometers and colorimeters DR 6000, DR 5000, DR 3900, DR 3800, DR 2800, DR 2700, DR 1900, and DR 900 from HACH® Company are suitable for performing this test although COD can also be performed on UV-Vis spectrophotometers and/or colorimeters from other manufacturers. For the listed instruments, the test is performed as follows:

[00343] Samples can be collected in clean glass bottles and/or plastic containers free of organic contamination. Samples are tested as quickly as possible after collection.

[00344] For analyzing a typical sample, a reactor is initialized and preheated to 150 °C. A DRB 200 reactor from HACH® Company is used herein; however, any suitable reactor can be used by following manufacturer-provided protocols. Different sample vials containing pre packaged reagents are obtained from HACH® Company based on the expected COD, with wider and narrower detection limits available. The ordinarily-skilled artisan will be able to choose the appropriate vials and reagents based on expected COD of the sample to be measured as well as previous test results.

[00345] 2 mL of sample is added to a typical vial containing digestion reagents, or for detection in the 250-15,000 mg/L range, 0.20 mL of sample is added to the vial using a micropipette. A second vial is prepared as a blank using deionized water. Both the sample and the blank are externally rinsed and wiped with a paper towel or lint-free wipe to dry. Vials are inverted to mix and placed in the reactor, where they are heated for 2 hours. The reactor is turned off and the vials are allowed to cool for 20 minutes or until the temperature reaches 120 °C. Vials are inverted several times and placed in a rack to cool.

[00346] The blank vial is externally cleaned and placed into the colorimeter or spectrophotometer. A zero reading is taken. The prepared sample vial is externally cleaned and placed into the colorimeter or spectrophotometer and a COD reading is taken. The blank can be used for several sample vials in the same lot of reagent vials and only requires replacement if absorbance changes by at least 0.01 absorbance units over time.

[00347] If desired, instrumental accuracy is verified using a series of standard solutions of known concentration. Factory calibration of the instrument can be adjusted to reflect known values of the standard solutions.

[00348] Total Nitrogen Test Protocol: The total nitrogen (total N) is measured for samples taken using the Urine and Wastewater Treatment System Sampling Procedure as described herein. Total nitrogen can be measured by any method known in the art such as, for example, using a Persulfate Digestion Method kit manufactured by HACH® Company (Loveland, CO, USA). Spectrophotometers and colorimeters DR 6000, DR 5000, DR 3900, DR 3800, DR 2800, DR 2700, DR 1900, and DR 900 from HACH® Company are suitable for performing this test although total nitrogen detection can also be performed on UV-Vis spectrophotometers and/or colorimeters from other manufacturers. For the listed instruments, the test is performed as follows:

[00349] Samples are tested as quickly as possible after collection. For analyzing a typical sample, a reactor is initialized and preheated to 105 °C. A DRB 200 reactor from HACH® Company is used herein; however, any suitable reactor can be used by following manufacturer- provided protocols. Nitrogen Hydroxide Digestion Reagent vials from HACH® Company are used herein; these contain pre-measured reagents useful for testing total nitrogen. The contents of one pre-measured packet of nitrogen persulfate are added to a first reagent vial for use in measuring a sample, and to a second reagent vial for use in measuring a blank. 0.5 mL of sample is added to one vial and 0.5 mL of deionized water is used to the second vial. Deionized water must be free of all nitrogen-containing species. The vials are capped and shaken vigorously for 30 seconds. The shaken vials are placed in the reactor for 30 minutes. Following reaction, the vials are removed from the reactor and allowed to cool to room temperature.

[00350] Pre-measured packets of Total Nitrogen Reagent A provided by HACH® Company are added to the sample and blank vials. The vials are capped and shaken for 30 seconds, then reacted for 3 minutes. After 3 minutes, the caps are removed from the vials and pre-measured packets of Total Nitrogen Reagent B provided by HACH® Company are added to the vials. The vials are capped and shaken for 15 seconds, then reacted for 2 minutes. Following reaction, 2 mL of the digested samples from the vials are added to separate Total Nitrogen Reagent C vials provided by HACH® company. A similar procedure is followed for deionized water blanks. The reagent vials are capped and inverted slowly 10 times to mix. After 5 minutes, the vials are cleaned externally and measured using a spectrophotometer or colorimeter.

[00351] Blanks can be saved for up to 7 days if kept in the dark at room temperature. When suspended solids appear in the blanks, they should be discarded and new blanks prepared. This procedure is effective at detecting at least 95% of nitrogen in ammonium chloride, ammonium sulfate, ammonium acetate, glycine, urea, and other organic nitrogen species.

[00352] If desired, instrumental accuracy is verified using standard additions to spike a fresh sample, or using a series of standard solutions of known concentration. Instrumental accuracy across different sources of nitrogen can be verified by preparing stock solutions using known amounts of different nitrogen species (e.g. ammonia, glycine, nicotinic acid-p-toluenesulfonic acid, or the like).

[00353] Total Phosphorus Test Protocol: The total phosphorus (total P) is measured for samples taken using the Urine and Wastewater Treatment System Sampling Procedure as described herein. Total phosphorus can be measured by any method known in the art such as, for example, using a U SEPA PhosVer® 3 with Acid Persulfate Digestion Method kit manufactured by HACH® Company (Loveland, CO, USA). Spectrophotometers and colorimeters DR 6000, DR 5000, DR 3900, DR 3800, DR 2800, DR 2700, DR 1900, and DR 900 from HACH® Company are suitable for performing this test although total phosphorus detection can also be performed on UV-Vis spectrophotometers and/or colorimeters from other manufacturers. For the listed instruments, the test is performed as follows:

[00354] Samples are tested as quickly as possible after collection. When samples are processed, pH should be adjusted to 7 using 5.0 N sodium hydroxide. Volume additions at any stage in the process (e.g. acidification, pH adjustment) should be corrected for when interpreting test results.

[00355] For analyzing a typical sample, a reactor is initialized and preheated to 150 °C. A DRB 200 reactor from HACH® Company is used herein; however, any suitable reactor can be used by following manufacturer-provided protocols. 5.0 mL of sample to be tested is added to a vial, followed by a pre-measured amount of potassium persulfate provided as part of a test kit available from HACH® Company. The sample is shaken to dissolve any powder and the sample vial is inserted into the reactor and allowed to react for 30 minutes. This reaction converts organic and condensed inorganic phosphates to reactive orthophosphate. The sample vial is removed from the reactor and allowed to cool to room temperature. 2 mL of 1.54 N sodium hydroxide is added to the sample vial and the vial is capped and inverted to mix. The vial is wiped with a lint-free cloth or wipe to clean and dry the outer surface of the vial, and the vial is then inserted into a cell holder in the spectrophotometer or colorimeter. The spectrophotometer or colorimeter is zeroed and a pre-measured amount of molybdate and ascorbic acid (herein, from a PhosVer® 3 powder pillow available from HACH® company) is added to the vial. The vial is shaken for 20-30 seconds to disperse the powder, which does not dissolve completely. After a 2-minute reaction time, orthophosphate in the sample has reacted with molybdate to produce a mixed complex having an intense blue color. The vial is again wiped with a lint-free cloth or wipe and inserted into the spectrophotometer or colorimeter and a total phosphorus reading is taken using absorbance at 880 nm for spectrophotometers or 610 nm for colorimeters (for a reduced phosphate/molybdate complex).

[00356] In a typical test, range for total phosphorus is from 0.06 to 3.5 mg/L PO4 ^3' . Samples showing a higher concentration should be diluted and re-tested for accuracy of reporting. If desired, instrumental accuracy is verified using standard additions to spike a fresh sample, or using a series of standard solutions of known concentration.

[00357] Total Suspended Solids Test Protocol: The total suspended solids (TSS) are measured for samples taken using the Urine and Wastewater Treatment System Sampling Procedure as described herein. Total suspended solids can be measured using any technique known in the art such as, for example, the test for Residue, Non-Filterable (Gravimetric, Dried at 103-105 °C) protocol from the US EPA National Exposure Research Laboratory. This method is useful for determining from about 4 mg/L to about 20,000 mg/L of suspended solids.

[00358] Briefly, a glass fiber filter is placed into a membrane filter apparatus. A vacuum is applied and the filter is washed with at least three 20 mL volumes of distilled water. Vacuum is applied until all traces of water are removed. The filter is dried in an oven at 103-105 °C for one hour and stored in a desiccator until needed. The filter is weighed immediately before use and handled with forceps or tongs only.

[00359] Sample volume is selected such that at least 1.0 mg of residue remains on the filter for a 4.7 cm filter. For other filter diameters, the ordinarily-skilled artisan will be able to select a sample volume equal to about 7 mL/cm ² of filter area and collect a weight of residue proportional to 1.0 mg.

[00360] The filter is weighed and placed in the filtering apparatus. Suction is applied. The filter is wetted with a small volume of distilled water. The sample is shaken vigorously and the preselected sample volume is applied to the filter using an appropriate means for the volume selected (e.g. graduated cylinder). Suction continues until all traces of water are removed. The graduated cylinder or other apparatus is washed with distilled water three times and the washes are applied to the filter. The filter, non-filterable residue, and filter apparatus are further washed with distilled water three times and all traces of water are again removed. The filter is removed from the filter apparatus and dried for at least one hour at 103-105 °C. The filter is allowed to cool in a desiccator and is weighed. The drying cycle is repeated until a constant weight is obtained. [00361] pH Test Protocol: The pH is measured for samples taken using the Urine and Wastewater Treatment System Sampling Procedure as described herein. A probe from a calibrated digital pH meter or water quality meter with pH measurement capability is immersed in the sample and pH value is displayed on a screen on the meter. Various pH meters and/or water quality meters can be used including the Myron L Ultrameter II CPFC ^E water quality meter available from the MYRON L® Company (Carlsbad, CA, USA).

[00362] Moisture Content Determination in Solid Cakes Test Protocol: To determine moisture content, a solid feces cake sample or portion thereof is placed in a tared aluminum pan and the pan and sample are weighed on an analytical balance. The sample is dried at 105 °C for at least 2 hours and the pan and sample are again weighed on the analytical balance. The following equation can be used to determine moisture content:

[00363] E. coli Extraction from Solid Cakes: E. coli (colony forming units or CFUs) is extracted from feces cakes produced by the non-sewered single toilet system described herein according to the following procedure. In brief, sterile phosphate-buffered saline (PBS) is added to a cake and mixed well. Dry cakes will absorb some of the solution, but some liquid supernatant should also remain in the tube. This liquid can be used for biological testing as described below.

[00364] In order to achieve the lowest possible detection limit, a minimum volume of PBS is added in order to leave enough supernatant to remove for biological tests. Approximately 1 mL of supernatant is needed for E. coli detection using the E. coli Detection Test Protocol described below. If liquid is difficult to pipette, more PBS may be added.

[00365] To extract E. coli , a sterile solution of PBS is prepared. The feces cake, or portion thereof, to be tested is weighed. The weighed feces cake is placed into a sterile 50 mL centrifuge tube. 20 mL of sterile PBS is added to the centrifuge tube and thoroughly mixed using a vortexer until the cake is broken up. The sample is allowed to sit for 5-10 minutes so that large solid particles can settle. The sample is optionally centrifuged at 400 rpm for 10 minutes to assist settling of large particles. Centrifugation should not be carried out at higher rotation or E. coli will drop out of the supernatant.

[00366] The tube is held at a 45° angle, allowing the supernatant to pool for easy removal. If the amount of supernatant is insufficient for sampling, 10 mL of additional PBS can be added and vortexing and optional centrifugation can be repeated. A 1000 pL pipette tip is used to remove the supernatant, taking care to avoid large particles that can clog the pipette tip.

[00367] E. coli Detection Test Protocol: E. coli (colony forming units or CFUs) is measured for samples taken using the Urine and Wastewater Treatment System Sampling Procedure as described herein. E. coli CFUs can be measured by any technique known in the art. Herein, a PETRIFILM™ E. coli! coliform count plate from 3M™ Company (St. Paul, MN, US) was used. The PETRIFILM™ plate contains modified violet red bile (VRB) nutrients, a cold-water soluble gelling agent, 5-bromo-4-chloro-3-indolyl-D-glucuronide (BCIG, an indicator of glucuronidase activity), and a tetrazolium indicator for facilitating colony enumeration.

[00368] The sample is blended or homogenized with an appropriate sterile diluent such as Butterfield’s phosphate buffered dilution water, 0.1% peptone water, peptone salt diluent, quarter- strength Ringer’s solution, 0.85-0.90% saline solution, bi sulfite-free letheen broth, or distilled water.

[00369] The PETRIFILM™ plate is placed on a flat surface. A top film on the plate is lifted. 1 mL of sample suspension prepared as described above is dispensed on the center of the plate’s bottom film, using a pipette held perpendicular to the inoculation area. The top film is rolled down onto the sample without trapping air bubbles. A 3M™ PETRIFILM™ Spreader is used to spread the inoculum over the entire plate growth area. The spreader is removed and the plate is left undisturbed for at least one minute, allowing a gel to form.

[00370] Following gel formation, the plate is incubated horizontally in a stack of no more than 20 plates. Incubation time can vary and the ordinarily-skilled artisan can select an incubation time appropriate to a given application based on instructions supplied by the manufacturer. Following incubation, colonies on the plates can be counted using a standard colony counter or another illuminated magnifier. A typical incubation time for detecting E. coli and/or coliform bacteria is 18-24 hours at 37 °C. Colonies appearing as blue to red-blue and associated with entrapped gas are to be counted as confirmed E. coli. Colonies should be counted within 1 hour of removal from the incubator or may be stored at -15 °C for up to one week prior to counting.

[00371] For extremely dense plates following incubation, the original sample may need to be diluted in order to obtain an accurate count, with appropriate volume corrections made based on the dilution volume. [00372] To convert CFU per mL results from the PETRIFILM™ to CFU per dry gram, the following equation can be used, where total liquid volume refers to the total volume of PBS added to the initial feces cake or portion thereof:

[00373] SAMPLING PROCEDURES

[00374] Using the Test Protocols described above, various properties of the output of system components, such as water, liquids components, and the like can be characterized using samples prepared with the following sampling procedure.

[00375] Urine and Wastewater Treatment System Sampling Procedure: Any suitable extraction device can be used to obtain a liquid sample from the urine and wastewater treatment system. For example, a syringe or volumetric pipette can be used to withdraw a specific volume of material, which may contain liquids and/or suspended solids, from the urine and wastewater treatment system. Alternatively, a greater volume of material than required by for analysis can be withdrawn into a sterile container and volume for testing can be measured separately. In an alternative aspect, a valve can be opened, allowing free flow of the liquid sample into a collection container. Samples collected in this manner can be used in any of the test protocols described herein.