BACKGROUND

[0001] Removal of contaminants from water and gaseous emissions is of paramount importance for a wide range of industries, including mining, chemical manufacturing, and power generation.

[0002] According to the Third National Climate Assessment, water demand in the United States alone is projected to increase by as much as 34% by 2060. In order to meet this demand, increased pressure has been placed on industries and municipalities to limit their impacts on water supplies. The United States is not alone in this issue and global legislation has placed stringent limits on the levels of certain substances that are allowable in water sources, thus forcing industries, namely mining and chemical manufacturing, to seek out innovative, cost-cutting methods to remove these chemicals from water. Concurrently, air quality has faced similar issues, with nearly 92% of the world population living in places where the World Health Organization air quality guidelines are not met. Again, increasing pressure from governments and public interest agencies has forced industries, principally, power generation companies, to seek out advanced scrubbing methods. Here, we describe a novel pumping system designed to remove contaminants using compressible microporous filters in a cost and time effective manner.

[0003] Currently, water and gaseous emissions are treated using a variety of methods, ranging from wet scrubbing, bioremediation, and chemical sorbents. Sorbents are the most widely used as they are simple to install/maintain. Activated carbon is the major sorbent utilized in fluid treatment. Activated carbon is derived from superheated carbon sources, typically charcoal, and is characterized by high porosity and surface area. This filter media has been used in a wide range of water filter systems. Additionally, sulfonated activated carbon is used to scrub mercury from flue gases. This material can exist as a powder, or can be mixed with a polymer and used as a static filter matrix. The other main class of filtration material is membranes. The term "membranes" describes any filter material whereby certain undesired contaminants are removed from a fluid matrix through a size selective process. Membranes are most commonly used in water treatment, specifically water desalination via reverse osmosis. Other membrane filters utilize charged coatings to specifically capture ions. In contrast, very little research has been conducted concerning the use of compressible microporous (e.g., sponge) materials for filtration. Various patents exist that utilize microporous materials as filters, but these filtration systems are static and do not incorporate a controlled compression system.

SUMMARY

[0004] Embodiments of the present disclosure are directed to filtration systems and methods of filtering a fluid using the filtration system. Some embodiments of the filtration system include a housing and a sorbent. The sorbent is contained in an interior chamber of the housing and is configured to adsorb one or more contaminants from a fluid contained in the interior chamber. The sorbent is in a compressed state, in which a volume of the sorbent is less than approximately 50% of its quiescent state volume.

[0005] According to some embodiments of a method of filtering a fluid, a fluid is received in an interior chamber of a first housing of a first filter stage through an input port of the first housing. The fluid is filtered using a sorbent contained within the interior chamber while the sorbent is in a compressed state, in which a volume of the sorbent is less than approximately 50% of a quiescent state volume of the sorbent. The filtered fluid is discharged from the interior chamber through an output port of the first housing.

[0006] Another embodiment of a filtration system includes a housing, which includes a column. The column encloses an interior chamber and has an input port, an output port, and a central axis. A sorbent is contained within the interior chamber in a compressed state, in which a volume of the sorbent is less than approximately 50% of its quiescent state volume. A source of compressed air is coupled to an air discharge port. When the housing is submerged in a liquid, air from the source of compressed air discharged through the air discharge port drives a flow of the liquid along the central axis, through the input port of the column, through the sorbent, which filters contaminants from the liquid, and out the output port of the column. [0007] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a simplified block diagram of an exemplary filtration system formed in accordance with embodiments of the present disclosure.

[0009] FIG. 2 is a simplified isometric view of an exemplary sorbent in a compressed state relative to its quiescent state volume.

[0010] FIG. 3 is a simplified side view of an exemplary passive filter stage in accordance with embodiments of the present disclosure.

[0011] FIG. 4 is a simplified side view of a sorbent capsule in accordance with embodiments of the present disclosure.

[0012] FIG. 5 is a simplified side cross-sectional view of an exemplary passive filter stage that includes the sorbent capsule of FIG. 4, in accordance with embodiments of the present disclosure.

[0013] FIGS. 6A-C are simplified diagrams of an exemplary filter stage filtering a fluid in accordance with embodiments of the present disclosure.

[0014] FIGS. 7A-C are simplified diagrams of a filtration process performed by an exemplary active filter stage in accordance with embodiments of the present disclosure.

[0015] FIGS. 8 and 9 are simplified diagrams of exemplary active filter stages and compressing mechanisms in accordance with embodiments of the present disclosure.

[0016] FIG. 10 is a flowchart illustrating an exemplary method of filtering a fluid using at least one filter stage formed in accordance embodiments of the present disclosure. [0017] FIGS. 11 and 12 are simplified isometric and cross-sectional views of a filtration system in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0018] Embodiments of the present disclosure are described more fully hereinafter with reference to the accompanying drawings. Elements that are identified using the same or similar reference characters refer to the same or similar elements. The various embodiments of the present disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0019] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art relating to the present disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0020] Embodiments of the present disclosure may also be described using flowchart illustrations and block diagrams. Although a flowchart or block diagram may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. Furthermore, embodiments of methods described herein include not preforming method steps and embodiments described herein. A process is terminated when its operations are completed, but could have additional steps not included in a figure or described herein.

[0021] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0022] Embodiments of the present disclosure are directed to a filtration system and methods of filtering a fluid (i.e., a gas and/or a liquid) using a compressible sorbent. FIG. 1 is a simplified block diagram of an exemplary filtration system 100 formed in accordance with embodiments of the present disclosure. In general, the system 100 is configured to filter contaminants from a fluid received from a fluid source 102. The fluid, which is represented by arrows 104, may be pumped or gravity-fed through the system 100 from the fluid source 102.

[0023] In some embodiments, the filtration system 100 includes one or more filter stages, which are generally referred to as filter stages 110, such as filter stages 110A and HOB. In some embodiments, each filter stage 110 includes a filter housing 112, and a sorbent 114. The filter housing 112 includes an interior chamber 118, an input port 120, and an output port 122. The sorbent 114 is contained in the interior chamber 118, and is configured to adsorb one or more contaminants contained in the fluid 104.

[0024] The input port 120 and the output port 122 may take on any suitable form. In some embodiments, the port 120 and 122 may include suitable fittings for connecting to fluid flow pathways or conduit 125 (e.g., tubing), for example.

[0025] In some embodiments, the filtration system 100 includes one or more valves 123. Each of the valves 123 is configured to control the flow of the fluid 104 through a portion of the system 100, such as the flow of the fluid 104 into or out of one of the filter stages 110 of the system 100, and through fluid flow pathways 125. The one or more valves 123 can take on any suitable form. Exemplary embodiments of the valves 123 include solenoid valves, check valves, and other conventional valves. In some embodiments, one or more of the valves 123 are controlled by a controller 124 of the system 100.

[0026] In some embodiments, the controller 124, which represents one or more processors that control components of the system 100, is configured to perform one or more functions described herein, such as the actuation of the valves 123, in response to the execution of instructions, which may be stored locally in memory of the system 100, or in memory that is remote from the system 100. In some embodiments, the processors of the controller 124 are components of one or more computer-based systems. In some embodiments, the controller 124 includes one or more control circuits, microprocessor- based engine control systems, one or more programmable hardware components, such as a field programmable gate array (FPGA), that are used to control components of the system 100 to perform one or more functions described herein.

[0027] In some embodiments, the filtration system 110 includes at least two filter stages 110, such as three or more filter stages 110. The system 100 generally operates to progressively filter the fluid 104 as the fluid 104 travels through each of the filter stages 110. For example, a flow of the fluid 104 from the fluid source 102 may be received at the input port 120 of the first filter stage 110A. As the fluid 104 engages the sorbent 114, the sorbent 114 adsorbs contaminants contained in the fluid 104. The controller 124 may open the valve 123 between the first filter stage 11 OA and the next downstream filter stage HOB to allow the fluid 104 to be discharged from the output port 122 of the first filter stage 11 OA, and received within the interior chamber 118 of the next filter stage HOB through its input port 122, to further filter the fluid 104. This process can be repeated using additional filter stages 110 that are downstream from the filter stage HOB relative to the fluid flow 104.

[0028] In some embodiments, the filter stages 110 are positioned at lower elevations as one moves in the downstream direction relative to the flow of the fluid 104 from the fluid source 102, such as shown in FIG. 1. Thus, each of the filter stages 110 may be located at a higher elevation relative to subsequent downstream filter stages 110. This allows gravity to feed the fluid 104 from the upstream filter stages 110 to the downstream filter stages 110.

[0029] The sorbent 114 can take on any suitable form and may comprise one or more materials that are configured to adsorb one or more contaminants contained in the fluid 104. In some embodiments, the sorbent 114 comprises a compressible sorbent material (e.g., sponge material). The illustrated sorbent 114 may represent a single piece of the compressible sorbent material, or multiple pieces of the compressible sorbent material.

[0030] The sorbent 114 may include an organic material and/or an inorganic material. Exemplary organic materials include activated carbon, polyurethane (e.g., polyurethane foam), cellulose, a plastic polymer, or other suitable organic material. Exemplary inorganic materials that may be used to form the sorbent 114, or a portion of the sorbent 114 include selenium, copper, aluminum, iron, zinc, nickel, titanium, or other inorganic material. Such inorganic materials may be in elemental or oxidized forms. Additionally, such materials may be in a nanoparticle form with a size between 5 nanometers and 500 nanometers. Exemplary nanomaterials used to form the sorbent 114 and exemplary sorbents 114 are disclosed in International Publication Number WO 2017/066453 Al entitled "Selenium Nanomaterials and Methods of Making and Using Same," which is incorporated herein by reference in its entirety. The material forming the sorbent 114 may also include a biofilter that is composed of biobased materials. In some embodiments, the sorbent 114 is formed of two or more of the materials identified above, or other suitable materials.

[0031] Different filter stages 110 may utilize a different sorbent 114. This allows each filter stage 110 to filter a different contaminant from the fluid 104.

[0032] In some embodiments, each sorbent 114 is contained within the interior chamber 118 in a compressed state in which a volume of the sorbent 114 has been reduced relative to the quiescent state volume of the sorbent 114. As used herein, the quiescent state volume of the sorbent 114 is the volume of the sorbent 114 under standard conditions for temperature and pressure (i.e., 20 °C and 1 atmosphere) when the sorbent 114 is not subjected to forces from other objects (e.g., compressive forces from a structure).

[0033] FIG. 2 is a simplified isometric view of an exemplary sorbent 114 in a compressed state 126 (solid lines) relative to its quiescent state volume 128 (phantom lines). The compression of the quiescent state volume 128 to the compressed state 126 may involve a compression of the sorbent 114 along any axis of the sorbent 114. For example, the sorbent 114 may be compressed along the illustrated x-axis, the y-axis, and/or the z-axis. In some embodiments, the compressed state 126 of the sorbent 114 has a volume that is less than approximately (e.g., +5%) 50%, 30%, 20%, or 10% of the quiescent state volume 128 of the sorbent 114.

[0034] In some embodiments, the sorbent 114 includes a microporous compressible material having pores in the range of less than 1000 μιη, for example. The compression of the sorbent 114 to the compressed state 126 narrows the pores of the sorbent 114. In some embodiments, the pores of the sorbent 114 in the compressed state are in the range of less than 200 μιη, such as less than 150 μιη or 100 μιη. As a result, reactive sites of the compressed sorbent 114 are forced closer together, which reduces contact time.

[0035] Embodiments of the filter stages 110 of the filtration system 100 include passive filter stages, in which the sorbent 114 is continuously maintained in the interior chamber 118 in the compressed state, and/or active filter stages, in which the sorbent 114 is transitioned from a larger volume state (i.e., relatively uncompressed state) to the smaller volume compressed state within the interior chamber 118.

[0036] FIG. 3 is a simplified side view of an exemplary passive filter stage 110 in accordance with embodiments of the present disclosure. As discussed above, the filter stage 110 includes a housing 112, and a sorbent 114 contained within an interior chamber 118 of the housing 112. The housing 112 includes an input port 120 and an output port 122. The housing 112 may be configured to make the interior chamber 118 accessible for installing the sorbent 114 using any suitable technique. For example, the housing 112 may have separate housing sections 112A and 112B, which may be separated to allow for the insertion of the sorbent 114 within the interior chamber 118. The housing sections 112A and 112B may then be fastened together using any suitable technique to complete the installation of the sorbent 114.

[0037] In the exemplary passive filter stage 110 of FIG. 3, the walls of the housing 112 defining the interior chamber 118 apply a compressive force to the sorbent 114 to maintain the sorbent 114 in the compressed state 126. This compression of the sorbent 114 may be along any of the axes described above with reference to FIG. 2. [0038] In some embodiments, a sorbent capsule 129 is formed by maintaining the sorbent 114 in the compressed state 126 using a jacket 130, as illustrated in the simplified side cross-sectional view of FIG. 4. The jacket 130 may compress the sorbent 114 along one or more of the axes shown in FIG. 2. In some embodiments, the jacket 130 completely encapsulates the sorbent 114. Alternatively, the jacket 130 may be a cylindrical jacket that generally operates to compress the sorbent 114 along two of the axes shown in FIG. 2.

[0039] The jacket 130 may take on any suitable form. In some embodiments, the jacket 130 is formed of a porous material, such as mesh, or other suitable porous material. This allows the fluid 104 to flow through the jacket and the sorbent 114.

[0040] In some embodiments, the jacket 130 is formed of a material that substantially blocks the flow of the fluid 104 through the jacket 130. Here, the jacket 130 may include one or more openings 132 (phantom lines) through which the fluid 114 may pass through the jacket 130 and expose the sorbent 114 to the fluid 104. Thus, the jacket 130 may fully encapsulate the sorbent 114, but include the openings 132 that allow the fluid 104 to travel from an exterior side of the jacket 130 to the interior side of the jacket 130 containing the sorbent 114. When the jacket 130 forms a cylinder surrounding the sorbent 114, the jacket 130 may restrict movement of the fluid between the open ends of the jacket 130.

[0041] The sorbent capsule 129 allows the sorbent 114 to be maintained in the compressed state 126. This allows for more efficient storage and transport of the sorbent 114. Additionally, the sorbent capsule 129 simplifies the installation of the sorbent 114 within the interior chamber 118 of the housing 112. For example, after separating the housing sections 112A and 112B, the jacket 130 containing the compressed sorbent 114 may be supported on the housing section 112B, and the housing 112A may be reattached to the housing section 112B to complete the installation of the sorbent 114 in the interior chamber 118 of the housing 112, as shown in the simplified side cross-sectional view of an exemplary filter stage 110 shown in FIG. 5. In some embodiments, the sorbent capsule 129 may still be slightly compressed by the walls of the housing 112 when installed within the interior chamber 118. Thus, the step of having to compress the sorbent 114 during its installation into the housing 112 (FIG. 3) may be reduced or eliminated to thereby simplify the manufacture of the filter stage 110.

[0042] FIGS. 6A-C are simplified diagrams of an exemplary active filter stage 110 filtering the fluid 104 in accordance with embodiments of the present disclosure. The active filter stage includes a compressing mechanism 136 that is configured to compress the sorbent 114 within the interior chamber 118 from a relatively uncompressed or expanded state 137 (FIG. 6A) to the compressed state 126 (FIG. 6B) while the interior chamber 118 is filled with the fluid 104. In some embodiments, the sorbent 114 substantially fills the interior chamber 118 of the housing 112 when in the expanded or uncompressed state 137, as shown in FIG. 6A.

[0043] During a filtering operation, the fluid 104 is initially received within the interior chamber 118 of the housing 112 through the input port 120, as indicated in FIG. 6A. In some embodiments, this step of the method involves opening the valve 123A to allow the fluid 104 to enter the interior chamber 118 through the input port 120, while the valve 123B is closed, as indicated in FIG. 6A.

[0044] The fluid 104 may be driven into the interior chamber 118 using any suitable technique. For example, the fluid 104 may be gravity fed into the interior chamber 118, pumped into the interior chamber 118, or driven into the interior chamber 118 using another suitable technique. If necessary, the interior chamber 118 may be vented using conventional techniques.

[0045] After the interior cavity 104 is filled or substantially filled with the fluid 104, the valve 123A is closed, as indicated in FIG.6B. The compressing mechanism 136 compresses the sorbent 114 contained within the fluid 104 from the expanded or uncompressed state 137 (FIG. 6A) to the compressed state 126, shown in FIG. 6B. The compression of the sorbent 114 forces the diffusion of the fluid 104 into the bulk of the sorbent 114, and drives the adsorption of contaminants contained in the fluid into the sorbent 114. [0046] The compressing mechanism 136 may take on any suitable form, including those described below. In some embodiments, the filter stage 110 includes an actuator 138 that drives the compressing mechanism 136 through a suitable mechanical connection (gears, levers, etc.) to compress the sorbent 114. In some embodiments, the actuator 138 may be a manual actuator, or a motorized actuator, which is controlled by the controller 124.

[0047] Following the compression process, the fluid 104 is discharged from the interior chamber 118. During this discharge of the fluid 104, the sorbent 114 may be maintained in the compressed state (FIG. 6B), or allowed to return to the expanded state 137, as shown in FIG. 6C. If the sorbent 114 is compressed during this fluid discharge stage, it may be allowed to return to its expanded state 137 (FIG. 6A) prior to receiving a new volume of the fluid 104.

[0048] In some embodiments, the fluid 104 is discharged from the interior chamber 118 by opening the valve 123B, as indicated in FIG. 6C. The fluid 104 may then be discharged from the interior chamber 118 using any suitable technique. For example, the fluid 104 may be gravity fed from the interior chamber 118 through the output port 122, or driven from the interior chamber 118 and through the output port 122 using any suitable technique, such as that described below.

[0049] FIGS. 7A-C are simplified diagrams of a filtration process performed by an active filter stage 110 using a compressing mechanism 136, in accordance with embodiments of the present disclosure. In some embodiments, the compressing mechanism 136 includes a piston 140 having a piston head 141 within the interior chamber 118, as shown in FIGS. 7A-C. The piston head 141 divides the interior chamber 118 of the housing 112 into a first chamber side 118A and a second chamber side 118B, in which the sorbent 114 is contained. In some embodiments, the piston 140 includes a rod or shaft 142 that is attached to the piston head 141. The rod or shaft 142 may be driven by the actuator 138 to move the piston head 141 along a central axis 144 of the housing 112 relative to the housing 112. [0050] After the interior chamber 118 of the housing 112 is filled with the fluid 104 (FIG. 7A), the actuator 138 (FIGS. 6A-C) drives the piston head 141 along the central axis 144 in the direction indicated by arrow 146 to compress the sorbent 114 within the fluid 104, as indicated in FIG. 7B. In some embodiments, during this compressing process, both the input port 120 and the output port 122 are closed by the valves 123A and 123B to maintain the fluid within the chamber 118, as indicated in FIG. 7B.

[0051] In some embodiments, the piston head 141 allows the fluid 104 to travel between the chamber sides 118A and 118B as it moves along the central axis 144 in the direction 146 to compress the sorbent 114 (FIG. 7B). In some embodiments, the piston head 141 does not seal the chamber sides 118A or 118B. In some embodiments, a gap exists between the piston head 141 and the housing 112, which allows fluid to travel between the chamber sides 118A and 118B during movement of the piston head 141 relative to the filter housing 112. In some embodiments, the piston head 141 includes one or more apertures 148 that allow the fluid 104 to travel through the piston head 141 between the first and second sides 118A and 118B, as the piston head 141 moves along the central axis 144 relative to the filter housing 112, as shown in FIG. 7B.

[0052] As mentioned above, the fluid 104 within the interior chamber 118 of the housing 112 may be driven from the interior chamber 118 and through the output port 122 using any suitable technique. In one exemplary embodiment, a piston 150 is used to discharge fluid 104 from the interior chamber 118 following the compression of the sorbent 114 (FIGS. 6B and 7B). In some embodiments, the piston 150 includes a piston head 152 within the interior chamber 118 and a shaft 154 that is connected to the piston head 152. An actuator, such as actuator 138, may be used to drive the shaft 154 and the attached piston head 152 along the central axis 144 relative to the filter housing 112 to discharge fluid 104 from the interior chamber 118 following the compression of the sorbent 114 (FIGS. 6B and 7B). In some embodiments, the piston head 152 divides the interior chamber 118 into chamber sides 118C and 118D, and forms a seal against the housing 112. During a fluid discharge step of the method, the valve 123B is opened and the piston 150 is moved along the central axis 144 from an initial position (FIGS. 7A and 7B) in the direction 156 to drive the fluid 104 within the chamber side 118D through the output port 122, as indicated in FIG. 7C.

[0053] In some embodiments, the sorbent 114 is supported on a structure 158 within the housing 112, such as a grating. The structure 158 prevents the sorbent from blocking the output port 122. The structure 158 includes openings 159, through which the fluid 104 may be delivered to the output port 122, as indicated in FIG. 7C.

[0054] The piston 150 may be combined with any suitable compressing mechanism 136. When the piston 150 is combined with the piston 140, the shaft 142 of the piston 140 may extend through the shaft 154 of the piston 150, as shown in FIG. 7C. This allows the pistons 140 and 150 to be operated independently by the actuator 138, or another suitable actuator. Other arrangements may also be used.

[0055] In some embodiments, each filter stage 110 includes compressing mechanisms 136 that are at least partially contained within the interior chamber 118 of the filter housing 112, such as that illustrated in FIGS. 7A-C. These embodiments generally operate best with filter housings 112 that are rigid or substantially rigid.

[0056] In some embodiments of the filter stage 110, the filter housing 112 is formed of a non-rigid, flexible, or malleable material that allows the sorbent 114 to be compressed using a compressing mechanism 136 that is external to the filter housing 112. In such an arrangement, the compressing mechanism 136 may take on any suitable form that allows for at least the partial compression of the sorbent 114 within the flexible or collapsible filter housing 112 during the compression stage (FIG. 6B).

[0057] In some embodiments, the compressing mechanism 136 is configured to pinch the filter housing 112 and the sorbent 114 contained within the interior chamber 118 of the housing 112. FIG. 8 is a simplified diagram of a filter stage 110 illustrating an exemplary form of such a compressing mechanism 136. In the illustrated exemplary embodiment, the compressing mechanism 136 includes a pair of rollers 160 that are positioned on opposing sides of the filter housing 112. During a compression operation, the rollers 160 rotate as the filter housing 112 and the sorbent 114 move relative to the rollers 160 to compress the sorbent 114 within the fluid 104. In some embodiments, the rollers 160 can be replaced with bars or other suitable components. Other mechanisms for pinching the sorbent 114 within the housing 112 may also be used.

[0058] Additional embodiments of the compressing mechanism 136 are configured to twist the filter housing 112 and the sorbent 114 contained in the filter housing 112 to compress the sorbent 114 during the compression stage (FIG. 6B). FIG. 9 is a simplified diagram illustrating a compressing mechanism 136 in accordance with exemplary embodiments of the present disclosure. In one exemplary embodiment, the compressing mechanism 136 includes a pair of end members 170 and 172 that are attached to opposing ends of the filter housing 112, as shown in FIG. 9. The end 170 is configured to rotate about the central axis 144 relative to the end 172 and twist the filter housing 112, as illustrated in FIG. 9. This twisting of the filter housing 112 also twists the sorbent 114 and compresses or wrings out the sorbent 114 within the fluid 104 during the compression stage (FIG. 6B). The member 170 can then be rotated relative to the member 172 to untwist the filter housing 112 and the sorbent 114 and return the sorbent 114 to its expanded state 137 (FIG. 6A or 6C).

[0059] Some embodiments are directed to a method of filtering a fluid 104 using the filtration system 100 formed in accordance with one or more embodiments of the present disclosure. FIG. 10 is a flowchart illustrating an exemplary method of filtering a fluid using at least one filter stage 110 formed in accordance with one or more embodiments described herein.

[0060] At 180 of the method, a fluid 104 is received in an interior chamber 118 of a housing 112, such as through an input port 120, as illustrated in FIG. 1. The fluid 104 may be delivered from a fluid source 102 to the input port 120 through conduit 125, for example.

[0061] At 182, the fluid 104 is filtered using a sorbent 114 contained in the interior chamber 118. In some embodiments of the filtering step 182, the sorbent 114 is in a compressed state, in which a volume of the sorbent is less than approximately 50% of a quiescent state volume of the sorbent 114, such as less than 30% or 10% of the quiescent state volume of the sorbent 114, for example, as discussed above. At 184, the filtered fluid 104 is discharged from the interior chamber 118, such as through an output port 122 of the housing 112.

[0062] In some embodiments, the filter stage 110 may be a passive filter stage, in which the sorbent 114 is maintained in the compressed state during the filtering step 182 using the walls of the housing defining the interior chamber 118 (FIG. 3), and/or using a jacket 130 (FIGS. 4 and 5).

[0063] In other embodiments, the filter stage 110 may be an active filter stage, and the method includes compressing the sorbent 114 within the interior chamber 118 from an expanded state 137 to the compressed state 126 using a compressing mechanism 136, such as discussed above with reference to FIGS. 6A-C, 7A-C, 8, and 9. For example, the compressing mechanism 136 may include a piston head 141 that divides the interior chamber into a first chamber side 118A and a second chamber side 118B. The piston head 141 moves along a central axis 144 of the housing 112 relative to the housing 112, and compresses the sorbent 114 on the second chamber side 118B from the uncompressed state to the compressed state, as described above with reference to FIGS. 7A-C.

[0064] Some embodiments of the discharging step 184 include moving a discharge piston 150 within the interior chamber 118 along the central axis 144 relative to the housing 112, and discharging the filtered fluid 104 in response to moving the piston 150, as generally shown in FIG. 7C.

[0065] In some embodiments of the method, the filtered fluid 104 discharged from the filter stage 110 (e.g., filter stage 110A of FIG. 1) is received within an interior chamber 118 of a housing 112 of a downstream filter stage 110 (e.g., filter stage HOB of FIG. 1) through an input port 120 of the downstream filter stage, such as shown in FIG. 1. The downstream filter stage may then proceed with performing the filtering step 182 and the discharging step 184 to further filter the fluid 104. This process may be repeated by additional downstream filter stages 110.

[0066] FIGS. 11 and 12 are simplified isometric and cross-sectional views of a filtration system 200 in accordance with embodiments of the present disclosure. Embodiments of the filtration system 200 operate to circulate and filter a liquid in which the system 200 is submerged.

[0067] In some embodiments, the filtration system 200 includes a housing 204 comprising a column 206 enclosing an interior chamber 208. The column 206 may take on any suitable form. In one embodiment, the column 206 has an input port 210, an output port 212, and a central axis 213.

[0068] A sorbent 214 is contained in the interior chamber 208 between the input port 210 and the output port 212. The sorbent 214 may be formed in accordance with one or more embodiments of the sorbent 114 discussed above. The sorbent 214 may be in a compressed state, in which a volume of the sorbent 214 is less than approximately 50% of its quiescent state volume, such as less than 30% or 10% of its quiescent state volume, for example. In some embodiments, the sorbent 214 may be in an expanded state relative to the compressed state within the interior chamber 208.

[0069] The sorbent 214 may be in the form of a sorbent capsule 216 having a jacket 218 that entirely or partially surrounds the sorbent 214. The sorbent capsule 216 and the jacket 218 may be formed in accordance with one or more embodiments discussed above regarding the sorbent capsule 129 and the jacket 130 (FIGS. 4 and 5).

[0070] In some embodiments, the sorbent 214 or the sorbent capsule 216 (shown), is supported within the interior chamber 208 on a flange 220 of the housing 204, as shown in FIG. 12. Other techniques for supporting the sorbent 214 or the sorbent capsule 216 within the interior chamber 208 may also be used.

[0071] In some embodiments, the filtration system 200 includes an air discharge port 222 (FIG. 12) positioned below the input port 210. The housing 204 may be supported above the air discharge port 222 using any suitable support structure, such as one or more supports 223, for example. A source of compressed air or gas 224 may be coupled to the air discharge port 222, and supply the port 222 with a flow of air or gas 226. In some embodiments, the filtration system 200 includes a diffuser 228 that is configured to diffuse the flow of air 226. Such diffusion of the airflow 226 may produce bubbles 230, as shown in FIG. 11. [0072] The air bubbles 230 from the air discharge port 222 and/or the diffuser 228 rise along the central axis 213, through the input port 210 and into the interior chamber 208, through the sorbent 214, and out the output port 212. The rising air bubbles 230 produce a flow of the liquid in which the filtration system 200 is submerged, as indicated by arrows 232, along the path of the rising air bubbles 230. Thus, the liquid is circulated through the sorbent 214 by the rising bubbles 230. The sorbent 214 filters the flowing liquid through adsorption, as discussed above, to remove contaminants from the liquid.

[0073] Although the embodiments of the present disclosure have been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the present disclosure. Additional embodiments and supporting information are discussed in the Appendix.