GOHCRETS FILTERING SYSTEMS AND METHODS

REFEREMCE TO PENDING PRϊQR PATENT APPLICATIONS

[0001] ThJs patent application claims benefit of (1 ) pending prior U.S. Provisional Patent Application Serial No. θO/834,553, filed 07/31/2008 by Gregory Majβrsky for CONCRETE FILTERING SYSTEMS AND METHODS, and (2) pending prior U.S. Provisional Patent Application Serial Mo, 60/913,029, filed 04/20/2007 by Gregory Majereky for CONCRETE FILTERING SYSTEMS AND METHODS, which patent applications are hereby incorporated herein by reference.

[G0Q2J Approximately 85 to 70% of the rural population in developing areas of the world do not have access to a safe source of water. See, for example, Water Partners international (2008). Water Related Facts. http://www.water.org/resourc6s/disease.htm. Accessed March 2008, In addition, more than five million people die from water-related disease. See, for example, Pacific Institute,. (2002). "Dirty Water: Estimated Deaths from Water-Related Diseases 2000 -2020.". These facts substantiate the need to provide dean drinking water to a large portion of the world's population, in fact, one of the report authors has personally witnessed people drinking from sewage and contaminated canals in the MinHang district of Shanghai, Ctiina. This observation reinforces the need to examine possible methods of providing suitable drinking water \n developing communities of the world. The need to supply dean drinking water can be emphasized by the following facts;

[0003] The World Health Organization estimates that 80% of all sickness in the world can be contributed to non-potable water and sanitation, See, for example, The Washington Post (1937). "Battling Waterbome Ills in a Sea of 950 Million," The

Washington Post February 1997,

IOO04J If no action is taken to provide suitable means of obtaining clean drinking wafer, as man as 135 million people will die from water-related diseases by 2020, See, for example, Pacific Institute, (2002). "Dirty Wafer: Estimated Deaths from Water-Related Diseases 2000 -2020.",

|0δ0S] L Data relating water, sanitation, and hygiene intervention has shown a decrease in sickness from diarrhea by 25-33%. See, for exampϋe, Esrey, SA, Potash, J.8., Roberts, L., and Shift, C. (1991). "Effects of Improved Water Supply and Sanitation on Ascariasis, Diarrhea, Dracuπculiasis, Hookworm Infection, Schistosomiasis, and Trachoma." World Health Organization, 89(5}, pp. 609-821, [OOOSJ Obtaining water for drinking and irrigation in rural areas has always provided a challenge to those who live far away from heavHy populated areas, in ancient times, the task of acquiring ciean water may have actually been easier due to the lack of centers of industry, large scale agriculture and relatively sparse populations who ate food free of artificial chemicals. Over time, the waste products of these processes have managed to contaminate both ground anά surface water. [00071 This leaves microbial infection as the only threat that has remained constant throughout history, and due to the increase of the human population in general, one would naturally expect m increase in the population density of many rural populations in both developing and developed countries. [0QS8J Typically, wafer in ruraf areas is collected from wells or from surface water. Surface water is easier to access, but may be higher in microbial content because it is also accessible by animals and humans for bathing and waste removal; anύ since the industrial revolution surface water has become necessary for a multitude of processes, as well as waste removal. [OøδS] Well water on the other hand, is less accessible (except artesian wells) and less prone to be polluted by waste products, but that water is not pure and stili can harbor quantities of microbes dangerous to humans. However, weli water is an important source of water for many rurai populations because grouπdwater deposits can be extremely large anϋ exist where no apparent surface water is

present Las Vegas, Nevada and Phoenix, Arizona are prime examples of how plentiful groundwater sources can be in desert climates. The purpose of this proposal is to introduce simple technology that may be able to remove enough bacteria from water in rural areas to enhance the health and quality of fife for rural populations around the world.

Overview of Other Low Cost and Low Energy ...Purification Technologies [0010| Chlorine is a widely available chemical available in tablet form that dissolves easily in water. Small amounts of chlorine are effective against most types of bacteria and in these concentrations chlorine is generally not harmful to humans. Chlorine has some disadvantages in that pathogens such as cysts (microorganisms in protective shells) and viruses require concentrations of chlorine high enough to be a danger to humans. Chlorine is also a hazardous substance that even in pill form should not come in to contact with iiving tissue. There may be some concern as to the hazards of long term exposure to chlorine as well In urban water treatment pianfs chlorine is removed from treated water before consumption and discharge for this reason.

[0011] Using old fabric for filtration has shown to significantly reduce bacteria counts and remove visibly unattractive sediments. Natural fabrics will swell and absorb water as it is poured through the fabric, trapping bacteria and sediments, there may also be a reduction ^' m chemical concentrations in water treated in this fashion as we! I. However, the economic condition of people who use this method is often very poor, so old clothing that is used to treat water must be replaced by buying or making new clothing, something that may not be consistently economic feasible. Also, the cloth filters will retain the trapped contaminants and must be washed separately in clean water (which wili become polluted) to maintain usefulness,

100123 Solar disinfection is very useful In areas where there is high UV exposure anά is very affordable, requiring only a plastic bottle with a cap to hold the water while UV radiation and high temperatures kiii organisms. However, the chemical

composition of the water does not change, cloudy weather almost nullifies the effectiveness of solar radiation in treating water, viruses and parasites may not be significantly affected and there may be some evidence that volatile organic compounds (VOGs) in the plastic constituting the containers may teach into the water as a result of high temperatures and high radiation. Additionally, the containers used for solar disinfection are typically plastic jugs. The fabrication of these Jugs is not yet environmentally friendly and the jugs do not decompose, they must be recycled IF such facilities are available. Plastic also may become contaminated with organic pαliutants in the water.

[0013] Organic Treatments, including plants like the Moringa ofeifera tree, may provide materials which may act as filters and have chemical properties capable of killing microorganisms. When handled correctly, these sources may provide effective filtration and treatment of water for consumption. Hov,'βver, the presence of these plants Is geographically specific and human populations may not live in dose proximity to such plants. Additionally, these plants or their seeds, leaves bark or fruit must be harvested and used in a sustainable manner to ensure continued survival of this source and to prevent an upset of the locaf ecosystem. Unfortunately, the water demands of the local population may be greater than what sustainable harvesting of such local plants can provide, creating a situation where the plant resource may be depleted or the local population may be impacted by the lack of sufficient potable water.

[00141 Sand filtration using sand columns has become popular due to the effectiveness of sand in removing bacteria and other pollutants, as well as the genera! availability of sand. However, sand filters must be backwashed everyday to maintain effectiveness. This requires the use of clean water that may already be in short supply If raw water resources are scarce. Effective sand filters are large and to wash the filter in a timely manner requires not only sufficient clean water but the ability to provide sufficient pressure, which rural and economically developing communities may not be able to do.

gβ01§3 In an embodiment, there is provided a water filter for producing potable water, the water filter comprising a pervious concrete section having an input portion anύ an output portion, the input portion for providing unfiitered water to the pervious concrete section, and the output portion for receiving filtered wafer from the pβα'ious concrete section and providing the filtered water to a location for collection as the potable water.

[001δ] In another embodiment, there is provided a method of producing potable water with a filter, the method comprising providing unfiltered water to an input portion of a pervious concrete section of the fiiter, receiving filtered water from an output portion of the pervious concrete section of the filter, and providing the filtered water to a suitable location for collection as the potable water. [0017} In yet another embodiment, there is provided a system for producing potable water, tie system comprising a water fiiter having a pervious concrete section with an input portion and an output portion, a storage portion for providing unfiElered water to the input portion of the pervious concrete section, and a collector portion for receiving filtered water from the output portion of the pervious concrete section so as to provide the potable water. [001 Sl Other embodiments are a^so disclosed.

[001 S] illustrative embodiments of the invention are illustrated in the drawings, in which:

[0020] FIGURES 1 A and 18 illustrates pervious concrete and conventional concrete, respectively; f 0021 J FIGURE 2 illustrates an example of Escherichia coii (E.coH) bacteria; [0022] FIGURE 3 illustrates the concentrations of iron, aluminum, and

magnesium for the seven samples taken during the erosion testing;

[0023] FIGURE 4 illustrates a water sample poured onto the surface of a pervious concrete filter;

[0024] FIGURE 5 illustrates concentrations of metals After erosion study;

[0025] FIGURES 6A and 6B illustrate the laboratory analysis results for bacterial dissolved oxygen for an unsieved filter and a sieved filter, respectively;

[0026] FIGURE 7 illustrates dissolved oxygen and temperature measurements;

[0027] FIGURES 8A and 8B illustrate dissolved oxygen results and the temperature difference results for the unsieved filters, respectively;

[0028] FIGURES 9A and 9B illustrate dissolved oxygen results and the temperature difference results for the sieved filters, respectively;

[0029] FIGURES 1 OA and 1 OB illustrate the percent removal of metals for the unsieved and the sieved filters;

[0030] FIGURE 1 1 illustrates the percent removal of sodium for the unsieved and the sieved filters;

[0031] FIGURES 12A-12E and 13A-13C illustrate various exemplary pervious concrete sections for a water filter; and

[0032] FIGURES 14A-14C illustrate a system for producing potable water

Detailed Description

[0033] In various embodiment, there are provided filters and methods that may filter contaminated water; thus producing safe drinking water to those in need. There is provided a filter formed with a non-conventional filter material. Permeable or pervious concrete has traditionally been used in producing pavement structures. This type of concrete has been applied in parking lots and green roofing projects to improve the quality of rain water before it enters urban drainage systems. See, for example, Haselbach, LM. and. Freeman, R. M. (2006) "Vertical Porosity Distributions in Pervious Concrete Pavement." Materials Journal Vol.103, No.6, Nov-Dec. 2006, pg.452-459. See also, Park, S., (2002). Chuπgnam National

University, Daejeon, Republic of Korea; Maπg Ha ₁ University of Florida." An experimental study on the water-purification properties of porous concrete", USA; 19 November 2002, Pervious concrete may be formed as a hardened mixture comprised of water, cement, and gravel Generally, the pervious concrete mixture has ϋttle to no sand. With the absence of sand, voids are present to aifow water to How through the concrete structure. Various embodiments herein specify shape, size, and effective grave! size to successfully filler contaminates from norvpoiable

10034] Concrete was chosen ύue to its wide use and availability throughout the world anό the fact that it has been used by mankind for construction for thousands of years. Global expertise in working with this material is present and sufficient Supply and production infrastructure are already in place. No additional energy is required to create systems to produce this traditional material already used worldwide. As a result, no additional pollution is added into the environment [0S3SJ The pervious concrete filter addresses the everyday lack of dean drinking water in many countries and has the potential to provide drinking water in flooded areas, where potable water infrastructure may be rendered inadequate. This filter can help maintain economic growth by improving overall public health and morale by providing improved drinking water quality. Sickness and fatality can be reduced by this low cost solution to improving water quality. |©S3β] The concrete filters may be able to remove enough bacteria from water in rural areas to enhance the health and quality of life for rural populations around the world, In addition, a globally omnipresent and recyclable material in concrete can be used to remove single celled organisms from water. The constituent materials for concrete exist ail over the world.

[0037] The concrete filter provides an effective water filtration system using an andeπt man-made material, concrete. The concrete filter may take advantage of the advances in pervious concrete technology and applications to provide a readily available materiai to produce potable water. Target populations are rural areas and suburban areas of cities without sufficient water treatment facilities. Four

aspects of sustalπability are addressed in these areas: (1) appropriate technology, (2) ecosystem sustainabilJty, (3) environmental sustainabϋiiy, and (4) socio-economic sustain ability.

|0D38] Pebbles, sand and other materials may be used to effectively remove 2 micrometer diameter bacteria from water. Construction of the concrete filters may be done locally and by hand or maximize efficiency of centralized production and distribution Cleansing or recycling of the concrete filter may be performed once it has become dogged with impurities with minimal environmental impact, [80391 Pervious concrete is a construction material that offers numerous economical and environmental benefits. Pervious concretes, like conventional concrete consists of Portland cement, water, and aggregates. The increased porosity of this material is achieved by eliminating the sand from the concrete mixture. By reducing the amount of sand in the mixture, air voids are created in the concrete allowing water to pass through the concrete. Pervious concrete has approximately a 15-25% void structure allowing between 3 to 8 gallons of water per minute to pass through one square foot section of concrete. National Ready-Msxed Concrete Association, NRMCA, (2005). "Pervious Concrete: When it Rains, it Drains." National Ready-Mixed Concrete Association, Sliver Spring, Maryland. Pervious concrete may also be recycled at the &nά of th& designed life. The porous nature of pervious concrete when compared to conventional concrete is shown in FIGURES IA and 18.

|S04δ] Concrete has been identified as an idea! material for filtering water, at least for organisms larger than a virus. Concrete may Include basic materials, such as pebbles, mud and sand. The four aspects of sustainabilily identified above are addressed berein-beiow.

[0041] One aspect is cost. The labor needed to produce concrete is fairly rcon-spedalized and does not require a high level of education. Cement Is the only component that needs to be produced in a factory, however, the production technology is basic and the ingredients are fairly low-cost Secondly, materials may consist of sand and pebbles, the glue that holds them together. Concrete may

also be easily produced from a combination of other common materials found in the earth's crust No container is required to hold the material together, as in a sand filter. Thirdly, in order to meet sustaiπabiiity goals, the concrete fitter periodically needs to have impurities removed. To accomplish this, the material can either be recycled (though that requires more energy) or, due the durabltity of the material, can be exposed to locally available chemicals and solar radiation. Finally, once the cement, pebbles and sand are made available, local human power can mix and pour the concrete into locally made frames. The entire filter assembly may also be assembled by local labor for a quick transition from delivery to drop off. |0S42] Sustainable developments in water quality technologies are widespread. The use of ozone, UV light, advanced filtration and biotechnology represent the cutting edge in efficiency and effectiveness In removing pollutants, but each requires significant amounts of energy, expensive facilities to house the specialized equipment and an educated workforce to maintain proper operation. Less advanced technologies listed in the following pages approach pure sustajπability, but have their own limits due to weather {solar heat), toxicity (chlorine and solar heat), availability of materials (Moήnga oieifera), the expense, effort or use of valuable clean water in replacing/cleaning material (sari doth and sand fsitørs), or needing a container, most likely made of artificial materia! such as plastic (sand filters}. Additionally, use of plastic in high temperature environments may increase organic compound concentrations in the water, [00431 Sustainable technologies should require a minimum of non-human energy and be able to use locally available materials for fabrication, use and cleaning. Sustainable water treatment shouid also require little or no formal education to maintain the system, it is believed the use of porous concrete filters meets these sustainable requirements.

Fabricating Porous Concrete

|δø44] Porous concrete may be fabricated in the same manner as normal concrete, but generally with less sand or fiy-ash content, as those materials have

a much smaller diameter and will fill in spaces between pebbles. The only difference is that the concrete is not finished to provide a smooth surface, which would prevent the flow-through of water. The pore ssze Is determined by a ratio of sand/fly ash to pebbles. After placement the concrete is compacted with a heavy roller and allowed to cure,

[0045] Recycled concrete materia! from clogged filters may be used as aggregate In new concrete filter systems. Cement is found all over the world. In fact, two of the largest cement producers in the world, Holcim and Lafarge, are located In over 75 countries worldwide. Cement should be readily available in many areas of the world.

|0048] Zeolites, which are microporous crystalline solids with well-defined structures, may be included as a material addition to the filter so as to improve removal of chemscais and provide nano-scafβ porosity to better remove viruses.

|0O471 Filter Alternatives

[0048] Pervious concrete may be chosen as a filter material due to the availability of materials needed to produce concrete filter samples, low fabrication cost, and the ability to recycle the concrete filters once the system became non-effective. Prior to selecting pervious concrete as a filtration material, a review of alternative point-of-use water treatment technologies was conducted. The benefits and disadvantages of each are presented in the following,

[S049J Chlorine is a widely available chemical available In tablet form that dissolves easily in water. Small amounts of chlorine are effective against most types of bacteria and in these concentrations chlorine is generally not harmful to humans.

[Qø§SJ Using old fabric has shown to significantly reduce bacteria counts and remove visibly unattractive sediments. Natural fabrics will sweii and absorb water as it is poured through the fabric, trapping bacteria and sedsmeπts. The economic condition of people who use this method is often very poor. Old clothing that is used to treat water must be replaced by buying or making new clothing, something that may not be economically feasible. Also, the cloth filters will retain the trapped

contaminants and must be washed separately in dean water (which wiii become polluted) to maintain usefulness.

[QSS1J Sand filtration nas become popular άue to the effectiveness of sand in removing bacteria and other pollutants, as well as the general availability of sand. However, rapid sand filters must be backwashed everyday to maintain effectiveness, which limits their effectiveness in areas lacking the electrical power necessary to run the backwash pumps.

[00S2J Each of these above-identified approaches has a number of advantages and disadvantages. This suggests that that a combination may provide a reliable, cost-effective, and environmentally responsible approach to pαtni-of-use water treatment. The goal of this study is to investigate pervious concrete as a complimentary approach that would take advantage of two distinct features: [0053] Pervious concrete filters are unsaturated, unlike cloth or sand filtration. This introduces an air-water interface that may provide treatment analogous to that in a trickling filter. The cement itself may provide treatment through its interaction with the tricky ng water, representing a second qualitative difference with respect to other filter materials.

|00S4J As shown in Table 1, the cost to produce a pervious concrete lifter is relatively inexpensive. The cost of a single pervious concrete filter with the dimensions of 10in,x10ϊn.x18in. is about $2.45, This cost includes only materials expenses for cement, rock, and water. Cost associated with mixing the concrete mixture was excluded since the sample could easily be mixed by hand. |δδS5J Additionally, not all locations around the world will have the industrial infrastructure necessary to produce chemical forms of water treatment. Developing areas may not be able to produce the required amount of potable water for an entire community. The necessary industrial infrastructure required to mass produce pervious concrete filters is already present in many of these areas. Table 2 provides cost estimates of the pervious concrete filter and currently available filter materials. See, for exampie, Existing, water filtration methods, (2007), http://www. coπsumerseareh . com/www/kitche n/water-fti ters/s ndex. html?scurce~ad

I I

words&gcJid=CNzGkqCRqlsCFRG3hgodhEbneQ. In addition, the estimated life of the filter is included.

[0OSS] The effects of viscous drag on the linear movement of E.cois. is discussed herein-beiow. There is shown in FIGURE 2, an example of Escherichia coH (E.coli) bacteria that is both deadly for humans and necessary for life. See, for example, http://www.mcb.harvard.edu/NewsEv8nts/Nsws/Berg.htrnJ, accessed July 2008, Without this bacterium, we cou^d not process vitamin K (potassium) or 8-vitanisns and would quickly die. At the same time, this bacterium can only ©xist safely on our skin or in our intestines. If it enters any through any other part of our body we quickly succumb to sepsis. See, for example, http://www-micro,msb.i8.ac.tJk/vicieo/Eco!!.htmJ, accessed July 2008. [0057] E.coii is probabiy the most commonly studied bacterium due to if s ss∑e (averaging 2um in length and 0.25 urn in diameter), if s large flageiia, which are also being studied as an inspiration for new nanotechnoiogy based propulsion, and ifs simple yet powerful chemical receptors that may be able to detect dangerous compounds. See, for example, http:/.%\vwlmmag.com/Stori8&/071801/Bioeingineers_aim_to _rsarness_bacteriaL motion_071801.htm!, accessed July 2008,

I E. coil's motion Is especially Interesting, as it is BhIe to propel itself forward using it's flagella to coif around the horizontal axis of it's body to achieve linear velocities of up to 10 times each bacterium's body length per second. See, for example, http;//www.naturexom/nature/journai/v435/rs7048/fig _m tab/πature03880_T2-htrπ], accessed July 2008.

|00SS] For non-Jinear movement, E.coH Is able to fan out it's ffageHa to form independent rotors that give it 3 dimensional movement similar to how deep sea exploration vehicles use an array of small propellers to provide multidirectional movement. See, for example, http://w^wiffimag.com/Stori8s/071801/8ioengsn8ers_ _. alm_to_ _. hamess_b3CtersaL motion_071801.html, accessed July 2008.

[OθβϋJ The focus of this invention is currently on E.coii's linear velocity and how the force of viscous drag acts on the bacterium's surface in open water and within a dosed channel. By constructing a profile of bacterial velocity and the resulting friction, a nonlinear change is expected in viscous drag as a function of the bacterium's linear velocity . Such a nonlinear change could indicate a meaningful threshold at the level of bacterial motion.

£00611 ft was necessary to simplify the environment in which the viscous drag on E.coH may be profiled. First, water is chosen as the medium, as it is common in all of E.coϋ's environments and its viscosity is readily known at various

|0082] Second, a temperature of 20 degrees Celcius is chosen as a standard temperature as it is approximately room temperature for water, and E.coii can be found in tøp water as a contaminant Having considered other temperatures, 0 degrees celcius was not a practical temperature and higher temperatures would only be found inside the human digestive tract, a natural habitat for E.coH, or approaching the boiling point of water, which would kill E. coll and render this study pointless. [OøδSJ Third, the velocity of water is chosen to be 1 urn/second as a reasonable

assumption to reflect E. coifs natural surroundings. Water flow velocities well in excess of 1 um/sec. would overwhelm E.coii's natural propulsion system, also rendering the purpose of this study useless. The fact Is taken into account that E.coϋ Is swimming against (upstream) and with (downstream) the direction of the flow of the water at an angle of 0 degrees to the direction of the water to simplify my calculations.

[S©S4f Lastly, the range of E.cαls velocities is chosen to be a range from 1 to 21 υm/sec to replicate a realistic environment where E.coii begins at a relative velocity of 0 urn/sec to the maximum velocity for a standard E.coii bacterium of 2 urn in length and 0.25 um in diameter. See, for example, htlp://www. rowiaπd .harvard . edu/labs/bacteπa/projects _^ fi Ia ment h tml , accessed July 2007)

[øδSSJ As shown in the calculations and the graphs, the prediction of a nonlinear change in viscous drag proved false in open water. However, within a dosed channel, the predictions of nonlinear change were proven true. By increasing the channel diameter from 0.3 um to 0.35 um when E.coii is swimming downstream, the force of viscous drag was reduced by almost a factor of 1 Q. When E.coii is swimming upstream, ihe channel diameter must be increased to a diameter of 0.4 um to realize an equivalent decrease in the force of viscous drag, [QQββ] Analysis of Poiseuille's Law Variables on Volumetric Flow (FIGURE 2} [®§S7] in ϊhe above discussion, the forces of friction and their magnitude of effect on a single E.coii bacterium as it swam in a linear motion through open water and through channels of various diameter were examined. The results showed that friction was not a significant force on an E.coii bacterium until the channel diameter was approximately the diameter of the bacterium. See, for example, http://biosystems.okstate.edu/darcy/LaLoi/basics.htm, accessed July 2008, I0O8SJ The next logical step is to analyze the volume of water that would flow through a single channel based on the previously stated average diameter of an E.coii bacterium which Is 0.2 micrometers (μm). See, for example, www.trπmag. com/Sf ones/071801 /B!oeng?neers_aifn_to_hamess_baterdai_motio

rtj)718G1.html, accessed July 2006.

[©OSS] The purpose of a water filter is to remove undesirable elements while being able to provide reasonable quantities of water over a short period of time, No one wants to wast all day for one glass of dean water. Filters typically remove contaminants such as metals, chemicals, colors and other solids. Bacteria are typically killed by chemicals, which can be hazardous, or by processes such as reverse osmosis and nmrccfϊltration. See, for example, http:/M*ww-aquaρuref0ters.com/contamfnates/108/bacteπa.htm l, accessed July 2006.

[00701 ^sny of these processes can be dangerous, expensive anά difficult to maintain without trained personnel, making them often unobtainable for Impoverished communities m both developing and undeveloped nations. The materials that constitute concrete are very cheap and widely available, and many societies have been performing various levels of concrete engineering since the Bronze Age. In addition, concrete is very durable and can take on either solid or porous forms, making It potential very suitable for a filtration medium. [0071] Volumetric flow is evaluated through a straight, non-sloping channel (perpendicular to the surface). This reflects a desire to maintain the simplicity of the calculations as slated in my previous analysis of friction against linear E. coll motion. The Initial analysis allows the reader to make cursory judgments of the potential feasibility of the eventual goal of these short research topics which would be the development of a concrete based water filter. With a circular, straight, non-sloping channel Potseuiile's Law is used. Further analysis generally requires the use of Darcy's Equation, which is applicable for both linear and nonlinear flow, An example calculation of Darcy's Law for the parameters specified in this analysis is included for comparison with Poiseuille's Law, To maintain consistency water temperature is kept at 20 degrees Celcius per the previous analysis, [dø?2i Based on the results of theoretical friction on a single E.coii bacterium In a closed channel of 2OC water, 3 variables from Poissuille's Law are selected to analyze. The first variable was the radios of the channel, as the

average E.coli's diameter \s 0.2 μm, A range of diameters was chosen from 4 μm to 1 μm. The second variable that was analyzed was length of the channel. Due to fairly rapid decreases in volumetric output with respect to length, a value range of 1 to 5 centimeters {cm} was used. The third variable was height of the column of water over the channel it was known in advance that a large column of water would be needed to provide the pressure to create respectable volumetric output, therefore a value range of 0.5 to 5 meters is chosen,

[0073] Taking snto account the fact that a 0.2 μm diameter (radsus - 0.1 prn) is used to effectively trap an average E.coli bacterium, volumetric flow increases inversely with the length of the channel L and volumetric flow increases exponential! y with the height of the water column h. The following parameters are chosen: r=0.1 μra L-t .OE-02 meters, h=2 meters. The resulting volumetric output was 2,77E-18 m3 per hour. Over tne course of 24 hours the output ss 6.84E-15 m3 per day for one channel. If the filter §s 50 m2 in size and the surface is 50% pores, the resulting volumetric output is 1.8 E-K)S m3 per day per Poiseuiiie's Law. Using the same parameters in Darcy's equation, the volumetric output is 7.05Eí11 rn3 per day,

|0®74f Exemplary calculations are provided as follows: flow rate ={(PI/8)*({{deπsity of water ^* gtavitatiori3i acce!eratiors{dovm} ^* height of the water column above pore)/!ength of pore ^Viscosity of water}*radius of pore to the 4th power)*3600= cubic meters/hour

I These calculations demonstrate that theoretically a concrete filter with pore diameter sufficient to trap an average diameter E.coii bacteria These calculations demonstrate that pervious concrete filters can be fabricated as regular concrete but without fine grained materials. These calculations demonstrate the ease and simplicity in fabrication of irsese samples does not require special training and special fabrication materials. These calculations examine the pervious concrete filter effectiveness in improving overall water quality for consumption or other uses. These calculations investigate the hypothesis that eliminating gravel larger than 0.25 inches (which is referred to herein-below as "sieved") is more effective in bacteria and inorganic compound removal than an unsorteti composition of coarse grains (unsieved) when tne filter dimensions were identical. IO07SJ The filters were tested by measuring water samples contaminated with bacteria and metals before and after the water passed through the pervious sample. The scope of this research was limited to the use of less hazardous materials in order to reduce the risk of injury or impairment to research personnel and minimize possible contamination of the laboratory environment. [0077J The bacteria used for conform research was Micrococcus luteus. This species has a size range of 0.5 to 3.5 micrometers and average size of 2,0

micrometers. See, for example, Landau, N. (2002) "Mass of bacteria." Online posting. Mors Apr 8, 2002. www.bfo.net/i>ionet/mm/mi(3Obio/2002-Aprii/021407.htm!. These size parameters allow for this bacteria as a syllable replacement for potentially more hazardous E. coil species. Diluted solutions of Micrococcus iuteus were prepared at 25, 30, 35, 40 and 45 mg of støck/L of deionized water. These samples were then measured for optical density as Total Suspended Solids (TSS), To simulate inorganic contamination and measure desaϋnization potential, solutions of increasing concentrations of sodium, iron, and copper were prepared. [0§78J The first test performed was an erosion test The metals analyzed included iron, aluminum, magnesium as total recoverable metals. Each test was performed for 5 minutes. Ail quantities, unless otherwise specified below, are given as mg/L. This was to examine how much, if any, cerneπtatious material or aggregate would be physically removed by the presence of flowing water, initially, the first three tests produced slightly turbid wafer with a small amount of pebbles.

As a result of this test, the filter was flushed with cold tap water for 70 minutes at a flow rate of 1 L/hr. Laboratory analysis of samples taken from the erosion test were measured for metals concentrations and pH at Evergreen Analytical in Lakewood, CO with an Inductively Coupled Plasma (ICP) instrument The erosion test samples were analyzed for total recoverable metals, with the primary focus being iron, aluminum, and magnesium. Samples 2, 3, and 4 experienced higher than expected levels of magnesium. Samples 4-7 were taken after the filter was rinsed for 1 hr. 10 minutes with cold tap water at 1 L/hour Results showed that both iron and aluminum concentrations were within the Environmental Protection Agency (EPA) secondary maximum concentration limits (MGLs) for drinking water.

See, for example, ERA (2007), Online publication, http:/λAWw.epa.gov/safewater/standards.litrn!. FIGURE 3 shows the concentrations of iron, aluminum _* and magnesium for the seven samples taken during the erosion testing. For example, FIGURE 4 illustrates a water sample being poured onto the surface of the pervious concrete filter. FIGURE 5

graphically illustrates concentrations of metals after the erosion study.

I Bacterial testing was performed on the sieved and unsieved filters. These tests were conducted to provide a comparison of filter performance between the un sieved vs. sieved lifters. The bacterial titration results are shown in Table

Pre-fiitration and post-filtration dissolved oxygen (DO) measurements were taken to measure oxygenation abilities of the uπsieved and sieved fHtere. The sieved filter produced an average of 0.21 mg/L increase in DO teveis over the uπsieved filter. Percent removal of bacteria was calculated on a mg of bacteria/L baas. One Micrococcus luteus has an average wet weight of 0,8 picograms, See, for example, Landau, N. (2002) "Mass of bacteria." Online posting. Moπ Apr 8, 2002, vw^A'.bio.net/bionet ^/ mrn/microbio/2002-Apri3/021407.fitm[. These size parameters ailow for this bacteria as a suitabie replacement for potentially more

hazardous E. cofi species. The filler was successful In removing bacteria from a concentration of about 10 ^s bacterial per ml of water to less than 1 per ml. The percentage of bacteπa! removal for both filters was well In excess of the EPA primary MCLs for bacteria (99,9%). Table 5 shows the bacterial dissolved oxygen results for the sieved and unsieved filters.

11 FIGURES 8A and 68 graphically illustrate the laboratory analysis results for bacterial dissolved oxygen for an uπsieved filter and a sieved filter as shown above in Table 5. Dissolved oxygen and temperature change measurements were also taken during pre-fs!tration and post-filtration. The unsieved filter produced a greater increase in D.O. and a greater decrease in wafer temperature. See Figure 7.

[Q0S2J FIGURE 7 graphically illustrates dissolved oxygen and temperature measurements. Tabie 6 shows another set of bacterial filtration results for the unsieved filters. Table 7 shows another set of bacterial filtration results for the sieved filters.

Dissolved metals analysis was performed to evaluate both filters' absiity to remove particles smaller than a bacterium (viruses, molecules and atoms) with the hope that this filtration system couid provide overall water quality improvements with respect to virus removal, removal of hazardous organic compounds, removal of hazardous metallic elements and possibly partial desaiinszation. The testing materials that were selected as contaminates included sodium, iron and copper. These contaminates are of minimum toxicity to provide a safe work environment and sufficiently small diameter to aliow the results to be extrapolated Io more hazardous, larger diameter compounds. Table 8 shows the dissolved metals dissolved oxygen results for the sieved filters. Table θ shows the dissolved metals dissolved o>ςrøen results for the unsieved filters. FIGURES 8.A and 88 graphically

illustrate dissolved oxygen results and the temperature difference results for the unsieved filters, respectively. FIGURES θA and 9B graphically Illustrate dissolved oxygen results and the temperature difference results for the sieved filters, respectively.

The results of the metals analysis found that iron was removed to less than the minimum detection level of the iCP in &l\ but the third trial. The concentration of sroπ In both cases were in excess of the EPA's secondary drinking water standard of 0.3 rng/L EPA (2007), Online publication, http://www.epa.gov/safewater/standards.htmi. The average percent removal of iron by the unsieved filter was 0.15% greater than the sieved filter. Sodium was

added to simulate sea water &t an average concentration of 35,000 rrsg/L The percentage of sodsum removed by both fillers increased similarly with each successive trial However, the average percentage of sodium removed by the sieved filter was greater than that of the unsieved filter by 1.13%, The rate of percent increase in sodium removal was 0.074 % greater for the sieved filter than the unsieved filter. Table 10 shows the dissolved metals filtration results for the unsieved filters. Table 11 shows the dissolved metals filtration results for the sieved filters.

[0086] FIGURES 10A and 10B iilustrate the percent removal of metals for the unsieved and the sieved filters, respectively. FiGURE 11 illustrates the percent removal of sodsum for the unsieved and the sieved filters. [0087] In addition, pH was measured for each sample. The range of pH of the

filtered water was 11.45 to 12.52. This very high level of pH Ls a concern and will be further investigated. However, polluted waters and industrial waters are typically acidic. Accordingly, the polluted waters or the industrial waters may be at feast partially neutralized with the pervious concrete filter as the cement may increase the pH (provided decreased acidity).

[OøSSJ Economic opportunities are created as a result of the need for fabrication of the concrete filters in these areas, Concrete is a recyclable materia! providing for both environmental and economical benefits, infrastructure is already in place around the world to produce concrete, thus little or no additional effort is needed to produce pervious concrete filters. New construction is not required in the production of these filters resulting In no significant increase in energy consumption. pøSSj Preliminary results demonstrated that the filter was effective for filtering bacteria; however, some other chemical pollutants may increase In concentration, particularly pH. Additional testing is needed to evaluate some of the unsuccessful factors discussed below.

I008θJ Unsuccessful factors include an unexplainable increase in dissolved copper concentrations (from 2 to 9 mg/L) and a very high pH (11 to 12). The high pH levels in the test samples are likeiy the result of large concentrations of hydroxide compounds in Portland cement, which generally makes the water non-potable. However, the high pH of the water may be offset by the fact that polluted natural waters and industrial wast® water are typically acidic, with a pH level less than δ. See, for example, Grippo, R. S- and Dunson, W.A. (2006) "Interactions between trace metals and low pH in reconstituted coal mine-poiiuied water." Online posting. Copyright 2006 htfp;//catinist.fr/?alv1odete~afficheNacpsfdt=2482829. See afso, Lenπtech (1998). Water treatment & Air Purification Holding B.V. Online Posting Copyright © 1998-2006 www.ienntech.com/water-potlution-FAQ.Iitm [0OS1] The initial dissolved copper concentrations were designed to be 0,13, 1.3, 13 and 130 mg/L; however, analytical results determined that 13 mg/L of

copper was found in all four samples. In addition, dissolved copper concentrations in the samples indicate an increase in copper passing through the filter. Further testing may be conducted to evaluate copper concentrations and removal using this type of filter,

|0S92] Looking at FIGURES 12A-12E and 13A-13C, there are shown various exemplary pervious concrete sections 1200A-1200E and 13GGA-13GUC. Pervious concrete sections 120QA-1200E include some efficient storage shapes. Section 1200A has the shape of a cube. Section 12008 has the shape of a raeiangiiar box. Section 1200C has the shape of a pyramid. Section 1200D has the shape of a trapezoidal box. Section 1200E has the shape of a triangular box. Altered ones of sections 1200A-1200E may indisdβ sections 1300A-1300C having a smaller area with a contour or other shape on tie input portion so as to Improve the flow rate. A substantial pressure may be created on the smalter area while aMowiπg a substantially similar volume of filtering. Trie dimensions of sections 130GA-13OQC may be configured to allow interlocking storage of similar ones of pervious concrete sections 13D0A-1300C

[0δ@3i Referring to FIGURES 14A-14C, am! in an embodiment there may be provided a system 1400 for producing poiabie water. System 1400 may include pervious concrete section, such as section 1300B, a storage portion 1402, ars optional waterproof gasket 1404, and a collector 1408. Water filter may include pervious concrete section 13008 with an input portion and an output portion. Storage portion 1402 may be configured for providing uπfHtered water to the Input portion. Optional waterproof gasket 1404 may be disposed between pervious concrete section 1300B and storage portion 1402 so as to prevent or reduce the How of unfϋtβred water long the interface between pervious concrete section 1300B and storage portion 1402. Collector portion 1408 may be provided for receiving filtered water from pervious concrete section 1300B.