WO2009075666A2

WO2009075666A2 - Modular water purification and delivery system

Info

Publication number: WO2009075666A2
Application number: PCT/US2007/086099
Authority: WO
Inventors: Jeffrey Brian Godfrey; Amanda A. Wise; Michael A. Taylor; Stephen E. Pazian
Original assignee: Prismedical Corporation
Priority date: 2007-11-30
Filing date: 2007-11-30
Publication date: 2009-06-18
Also published as: WO2009075666A3

Abstract

A modular filter system is provided with one or more modules that can be interchangeable, depending upon the specific application or specific health or environmental issue presented. Disclosed combinations can include any of the following modules in any relative position to one another: (a) a microbiological contaminant mitigation module, preferably in the form of an inverted u-shaped hollow fiber filter module wherein the fibers have ends potted on the downstream side and that consists essentially of hydrophilic fibers for water filtration with a small amount of hydrophobic fibers for venting of entrapped air; (b) a first chemical mitigation module, preferably in the form of an adsorption module comprising carbon or the combination of carbon and a deionization resin; and (c) a second chemical mitigation module, preferably in the form of a deionization resin module.

Description

MODULAR WATER PURIFICATION AND DELIVERY SYSTEM

BACKGROUND

Technical Field:

[0001] A portable, modular water filter is provided with one or more modules that can be interchangeable, depending upon the specific application and specific health or safety issue presented. The combination of modules may include a microbiological contaminant mitigation module preferably in the form of a hollow fiber filter module, a first chemical mitigation module preferably in the form of an adsorption module comprising carbon or the combination of carbon and a deionization resin, and a second chemical mitigation module preferably in the form of a deionization resin module. The assembled filter may present the modules in any relative position with respect to one another.

Description of the Related Art:

[0002] In many places in the world, water must be treated in an economical and convenient manner for before it is suitable for drinking by people. In this regard, portable drinking devices are available that provide filtration of microorganisms from drinking water.

However, currently available portable filtration devices are typically inadequate for the removal of protozoan cysts from water because the filter effective pore size is not sufficiently small. Further, currently available portable filtration devices also typically fail to filter small bacteria particles because of the pore size problem. Filtration media possessing the capability to filter cysts of 1 to 3 μm size and smaller bacteria particles are relatively dense, thereby inhibiting the flow of water through the media. As a result, such a portable filter device requires an excessive amount of strength to use and therefore many user are unwilling or unable to use these devices.

[0003] One approach to solving this problem is to provide a greater surface area within a small volume in combination with increasing the effective pore size. One filter media that meets these criteria is hollow fiber membrane bundles. The large surface to volume ratio of the hollow fibers greatly increases the area available for contact with the water flowing through the bundle. But even with the application of hollow fiber membrane bundles, the pressure drop across a filter capable of being deployed as a portable bottle filter is substantial. Many currently available hollow fiber membrane filters provide a flow rate of only about 12 to 35 ml per second at an applied pressure of 10 psig. Any blockage or other restriction to the flow of water through the membrane bundle results in even slower flow rates, rendering the device unacceptable to many users.

[0004] Because the use of hollow fiber membrane bundles in portable filter applications may result in air accumulating within the bundle housing between uses, a large percentage of the squeezing pressure must be used to expel air from the filter. While the air is venting, the flow of water exiting the filter is lessened. It may take several minutes of continuous flow to fully purge the filter of air. Another problem that may be encountered if air is allowed back into the individual hollow fiber membranes, which may cause membrane blockage.

[0005] Other problems associated with hollow fiber membrane filters is with their use for the treating highly polluted water which can result in the hollow fibers cohering together into a mass upon which organic matter can accumulate. The effective membrane surface area of the hollow fibers is reduced causing a decrease in filtering flow rate. As a result, the hollow fiber membrane bundle must be periodically subjected to surface cleaning and/or back washing, which is not practical for a portable device in the field.

[0006] Further, portable water filtration or purification devices tend to be fixed in design, meaning that once in the field, they cannot be modified to meet the particular water quality problems encountered unless multiple purification systems are incorporated. Obviously, for portable devices used in the field, multiple devices would be unwieldy.

[0007] Thus, hollow fiber bundles alone are not entirely effective as a filter media. What is needed is a flexible system that can provide multiple filter media and that can be easily reconfigured to address the particular environmental issue present. Typically, the major concerns in connection with surface water encountered in the field are protozoal and parasitic cysts and bacteria. These are commonly addressed by size exclusion filters, but flow rate and pressure required remain a problem. Bacteria and viruses can also be mitigated with disinfectants. Cysts are more resistant to disinfectants, which require extended exposure times to be effective. Many other potential hazards likely to be present in available surface water are not addressed by filtration or disinfection. These include various chemical contaminants, such as: inorganic chemicals, including arsenic, cyanide and beryllium; organic chemicals, including pesticides, like aldrin, dieldrin, endrin and endosulfan; and biological toxins from bacteria and algae. In environmental disaster situations other man- made contaminants may be present such as solvents and gasoline derivatives. In many cases environmental conditions or man-made contamination may impart noxious tastes and odors that render water unpalatable. [0008] Another potential requirement of personal water purification is mitigation of nuclear biological and chemical warfare (NBC) agents in water. By addition of augmentation capability with dry reagents, it would be possible to produce nutritional or therapeutic fluids in remote settings.

[0009] To be effective against all categories of contaminants, filtration systems are needed that can be adapted or reconfigured with relative ease.

SUMMARY OF THE DISCLOSURE

[0010] In satisfaction of the aforenoted needs, a modular filter is provided with one or more modules that can be interchangeable, depending upon the specific application or specific health or environmental issue presented. Disclosed combinations can include any of the following modules in any relative position to one another:

[0011] (a) a microbiological contaminant mitigation module, preferably in the form of an inverted u-shaped hollow fiber filter module wherein the fibers have ends potted on the downstream side and that consists essentially of hydrophilic fibers for water filtration with a small amount of hydrophobic fibers for venting of entrapped air;

[0012] (b) a first chemical mitigation module, preferably in the form of an adsorption module comprising carbon or the combination of carbon and a deionization resin; and

[0013] (c) a second chemical mitigation module, preferably in the form of a deionization resin module.

[0014] The modular configuration provides dynamic capabilities within a single system that enables field modification and cleaning of the system to meet the purification requirements of a given situation. Modification of the system enables mitigation of all categories of contaminants likely to be encountered.

[0015] One disclosed system comprises a prefiltration module, an anti-microbe and particulate module, an inorganic chemical agent module, an organic chemical agent module, and a noxious taste and odor module. The modules are capable of mitigation of different categories of contaminants or can function synergistically to address various categories of contaminants. The interconnections may be either reciprocal threaded connections or other types of universal interconnection, thereby enabling interconnection of any modules in any sequence or interconnection of multiple redundant modules to mitigate very high levels of specific contaminants, such as heavy metals during chemical warfare agent contaminated environment.

[0016] In a refinement, the modules may include external connections such as hose barbs, o-ring based snap quick-disconnects or other sterile connections.

[0017] A prefilter, if used, is preferably detachable and employed upstream of a first or primary filter module regardless of whether the primary module is a hollow fiber, carbon or the ionizing resin filter. The prefilter may consist of a single mesh sieve, a series of progressively tighter mesh sieves or a progressively tighter porosity depth filter as flat stock, pleated or spiral wound configurations. The prefilter serves to retain larger particulates such as biological and inorganic debris, preventing clogging of downstream modules.

[0018] By way of example, the first module or primary water filter module may include looped hollow fibers with potted ends. Both ends of the fibers are potted at the outlet end of the module. The inverted u-shaped looped portion of the fibers is directed towards the inlet end of the module or towards the pre-filter. Two types of hollow fibers are utilized. About 99% of the fibers are hydrophilic in use for water filtration and about 1% of the fibers is hydrophobic and is used to release entrapped air from the chamber that accommodates the hollow fibers. The hydrophilic fibers have a pore size ranging out of 0.005 to about 0.4 μm, more preferably from about 0.02 to about 0.22 μm, still more preferably from about 0.2 to about 0.1 μm. The hydrophilic fibers are preferably fabricated from polysulfone, polyethersulfone or an equivalent. The hydrophobic fibers are preferably made from polypropylene or an equivalent.

[0019] A second module may be a chemical adsorption module comprising granulated carbon or granulated carbon treated with a deionization resin or a suitable equivalent. In one embodiment, the organic filtration stage comprises a resin bed treated for retention of organic contaminants and commonly used additives in municipally-treated water.

[0020] A third module may a deionization stage, comprising a bed of deionization resin beads. The resin bed preferably comprises a mixture of pharmaceutical grade resins with strong anion exchanger (cation-impregnated) and strong cation exchanger (anion- impregnated) chemistries, binding dissociable ions and other charged particles with a very high affinity. In an embodiment, the deionization resin bed comprises mixed anion- and cation-impregnated resin beads with weakly associated hydrogen or hydroxyl groups, respectively. The skilled artisan will recognize other types of ion-exchange resins that could also be utilized in this stage.

[0021] A female-female threaded adapter may be employed which allows the downstream module to be connected to a collapsible water bottle or collapsible sport bottle. Such a female-female threaded adapter would connect the downstream module, with a 40 mm fitting to a conventional sports bottle, such as one having a 20 mm fitting.

[0022] Other advantages and features will be apparent from the following detailed description when read in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] For a more complete understanding of the disclosed methods and apparatuses, reference should be made to the embodiment illustrated in greater detail on the accompanying drawings, wherein:

[0024] FIG. 1 is an elevation or view of a modular filtration system made in accordance with this disclosure;

[0025] FIG. 2 is an exploded view of the filtration system shown in FIG. 1 ;

[0026] FIG. 3 is an elevation will view of yet another modular filtration system made in accordance with this disclosure;

[0027] FIG. 4 is a sectional view of the filtration system shown in FIG. 3;

[0028] FIG. 5 is an exploded view of yet another modular filtration system made in accordance with this disclosure; and

[0029] FlG. 6 is a partial exploded view of a female-female adapter used to attach a downstream module to a water bottle such as a sports bottle.

[0030] It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0031] Λ filtration system 10 with dual modules 11, 12 is illustrated in FIG. 1. The system 10 includes an inlet housing 13 which features a barbed inlet 14 for connection to a flexible water supply line (not shown). The inlet housing 13 serves as an end cap which is threadably connected to the housing 15 of the module 11 as illustrated in FIG. 2. Referring to FIGS. 1 and 2 together, in a preferred embodiment, a prefilter element 16 is utilized to retain larger particles. Λ prefilter 16, if used, is preferably employed upstream of a first or primary filter module 1 1 regardless of whether the primary module 11 is a hollow fiber, carbon or the ionizing resin filter. The prefilter 16 may consists of a single mesh sieve, a series of progressively tighter mesh sieves or a progressively tighter porosity depth filter as flat stock, pleated or spiral wound configurations. The prefilter 16 serves to retain larger particulates such as biological and inorganic debris, preventing clogging of downstream modules. Use of progressive porosity mesh sieves with extended lateral faces provides a means of self- cleaning due to the tangential flow across the vertical surface of the mesh. Construction of the framework of the prefilter from elastomeric materials enables the base 27 of the prefilter 16 to serve as a gasket between the inlet housing 13 and the inlet 17 of the module housing 15. [0032] The module 11 may also accommodate an additional filter element such as a hollow fiber bundle 18, an organic filtration stage 19 or a deionization stage 21 (see FIGS. 4 and 5). Returning to FIGS. 1 and 2, the housing 15 of module 11 includes the female threaded element 17 which receives the male threaded element 22 of the inlet housing 13. Consequently, the housing 15 also includes a male threaded element 23 which is threadably received in the female threaded element 24 of the housing 31 of the succeeding module 12. Gaskets 25, 26 can be utilized for sealing purposes. The prefilter mesh 16 may also be equipped with the gasket 27 thereby eliminating the need for separate gasket between the housing 13 and housing 15. The end housing 28 includes a female threaded element 33 (not shown FIG. 2, see FIG. 4) that threadably engages the male threaded element 34 of the housing 31 as well as a hose barb 29. It's

[0033] The dual module system 10 shown in FIGS. 1 and 2 will preferably employ three or more filter elements including the prefilter screen 16, a hollow fiber bundle 18 and one or both of the organic filtration stage 19 and deionization stage 21.

[0034] Similarly, the filtration system 10a shown in FIGS. 3 and 4 can accommodate at least three filter elements including a prefilter 16, hollow fiber bundle 18 and organic filtration stage 19 or deionization stage 21. Also, more than one type of filtration stage may be accommodated in any given module. That is, an organic filtration stage 19 and deionization stage 21 may be accommodated in a single module housing or either of these types of stages may be combined with a hollow fiber bundle stage in one module housing. Any of the housings may be equipped with a restraint element or screen 35 as seen in FIG. 4 that can be used to separate different types of filter stages from one another. [0035] Turning to FIG. 5, a three module system is disclosed that includes three modules 1 1 , 12, 37 for accommodating various combinations of filter stages. In the specific example shown in FIG. 5, the hollow fiber bundle stage 18 is followed by a deionization stage 21 and an organic filtration stage 19 is sandwiched between a pair of deionization stages 21. The hollow fiber bundle 18, organic filtration at 19 and deionization 21 stages can be presented in any order and stages may be repeated or duplicated, depending upon the hazards present. Tf a prefilter 16 is used, the prefilter 16 should be disposed in the inlet housing 13.

[0036] The organic or chemical adsorption module 19 preferably comprises granulated carbon or granulated carbon treated with a deionization resin. In one embodiment, the organic filtration stage comprises a resin bed treated for retention of organic contaminants. The illustrated embodiment incorporates a form of styrene divinylbenzene commercially available from Rohm & Haas of Philadelphia, PA, USA under the trade names Ambersorb 563. Ambersorb 563 removes certain residual organic contaminants, such as endotoxins, as well as commonly used additives placed in municipally treated waters (e.g., chlorine, trihalomethanes and chloramine).

[0037] The deionization stages 21 preferably comprises a bed of deionization resin beads. The resin bed preferably comprises a mixture of pharmaceutical grade resins with strong anion exchanger (cation-impregnated) and strong cation exchanger (anion-impregnated) chemistries, binding dissociable ions and other charged particles with a very high affinity. In an embodiment, the deionization resin bed comprises mixed anion- and cation-impregnated resin beads with weakly associated hydrogen or hydroxyl groups, respectively. The ion exchange resins of the preferred embodiment comprise styrene divinyl benzene. Such resins are available, for example, from Rohm & Haas of Philadelphia, Pa. under the trade name IRN 150, or from Sybron of Birmingham, NJ. under the trade name NM60. Cation exchangers exchange hydrogen atoms for any dissolved cations in the diluent. Common dissolved cations include sodium (Na⁺), calcium (Ca²⁺) and aluminum (Al³⁺). The anion exchange resins exchange hydroxyl ions for any anions present in an aqueous solution. Common anions include chloride (Cl^") and sulfides (S^2"). The resin bed 32 additionally retains some endotoxins that escape the upstream filtration components. The skilled artisan will recognize other types of ion-exchange resins that could also be utilized in this stage.

[0038] Thus, each uniform module 11, 12, 37 includes a housing 15, 31, 41 with an inlet or proximal end 17, 24, 42, a cylindrical housing body 15, 31, 41 and an outlet or distal end 23, 34, 43. The preferred configuration is a cylinder. The proximal and distal ends consist of reciprocal male 23, 34, 43 and female 17, 24, 42 threaded fittings that allow easy and fast interconnection of modules.

[0039] These module housings 15, 31, 41 are preferably at or less than 12 inches in diameter by 18 inches in height, more preferably they are at or less than 6 inches in diameter and 6 to 12 inches in height and more preferably 1/2 to 3 inches in diameter and 2 to 4 inches in height. The contents of the modules 1 1, 12, 37 contain filtration components to mitigate all categories of contaminants likely to be encountered in source waters.

[0040] The hollow fiber bundle module 18 is used for microbiological contaminant filtering. Other filters may be used instead of hollow fibers. A suitable microfilter is preferably used to retain protozoal and parasitic cysts, bacteria, other potentially toxic environmental toxin such as algae and particulates. Because most radionuclear contaminants have a tendency to bind particulates, this module can also provide effective mitigation of these contaminants. Use of 0.01 micron or smaller porosity microfilters in this module also mitigates virus, aggregated bacterial toxins and larger molecular weight environmental toxins. If a hollow fiber bundle is not used, a substitute microfiler can be configured as a single flat filter, pleated filter, spiral wound filter or hollow fiber. All configurations should be attached to the module housing to assure an integral seal of the filter to the housing. Alternative materials may be incorporated to facilitate venting such as hydrophobic materials such as PTFE, polypropylene or polyethylene.

[0041] Enhanced anti-microbial activity can be incorporated into the system through use of disinfectants in the source water bag or inclusion of antimicrobial agents within modules.

These agents could include immobilized halogens, iodinated or brominated resins, and silver impregnated carbons or resins or combinations of these agents.

[0042] The chemical mitigation modules 19, 21 can contain adsorptive agents such as carbon or synthetic carbon-like agents, deionization resins, selective affinity agents or combinations of these agents. These agents can be contained within porous or mesh restraints 35, porous enclosures or as free particles. These modules are effective for mitigation by retention of organic chemicals, such as pesticides, herbicides, insecticides, solvents, gasoline degradation products. It is also effective at mitigation by retention of inorganic chemicals, such as heavy metals and dissociable salts.

[0043] Additional chemical mitigation utilizes a non-woven material wrap impregnated with either carbon and/or deionization resin. This wrap is located around the hollow fiber bundles serving to cushion the bundle from shock while enhancing the chemical mitigation capacity.

[0044] Weak acid deionizer containing modules can preferentially retain heavy metals; ferrous agents can retain arsenic and cyanide. Combinations of carbon and resin within modules are more efficient for mitigation of offensive odors and tastes.

[0045] External connections include fitments that match the module housing inlets 17, 24, 42 and outlets 23, 34, 43. In addition to the threaded connections shown, the opposing ends of these fitments can be hose barb fittings, bayonet fittings, Luer fittings or o-ring based snap quick-disconnect fittings.

[0046] For static (stationary) use, the inlet housing or initial module 13 attaches to a reciprocal male or female fitment incorporated into a source water reservoir bag. This bag can contain a means of reversible opening to allow filling and closure. These types of closures can include, but are not limited to single and double zip-lock fitments, hook and loop fasteners, pinch clip closures, roller closures, other lock and key fittings.

[0047] Product water can be collected in a clean water bag or any desired receptacle. Use of a non-elastic or minimally elastic polymer for the clean water bag enables the bag to be a self-limiting flow control. FIG. 6 illustrates a female-female adapter 50 that can be used to connect male threads 23, 34, 43 of a downstream module 1 1, 12, 37 to a water bottle or sports bottle 51 . Typically, the modules 1 1, 12, 37 are 40 mm wide and a conventional sports bottle 51 is 26 mm wide. Wide-mouth sports bottles are also known and therefore a 40 mm-40 mm female-female adapter or other suitably sized adapter may also be required in such a situation. [0048] Through the use of modular contaminant specific components all categories of contaminants can be mitigated. This option can include use of redundant modules that can be used to mitigate the elevated contaminants levels associated with man-made disasters or extraordinary natural occurrences. In this manner, rehydration in contaminated settings can be accomplished using available source water that may be contaminated highly toxic chemical or biological agents without having to extricate from the setting, decontaminate, rehydrate, re-robe in hazard material protective garments and re-enter the contaminated setting. Additionally replacement of spent modules does not require replacement of the remaining still functional portions of the system.

[0049] Augmentation or addition of reagents to the product water to produce solutions rather than water can be achieved by addition of reagent to the filtration module 11, 12, 37 or to the collection bag. Maintenance of sterility the prepared solution would require reagent placement in the filtration modules 11, 12, 37 enabling filter sterilization as the solution passes through the filter system. For sterile solutions, where reagents are added to the collection bag, the reagents must be pre-sterilized.

[0050] For mobile use, the disclosed modules terminal interconnects can be connected to a bite tube or hazardous materials mask or protective suits. Heavily silted waters particulate load can be mitigated with multiple prefilters of progressively tighter pore mesh to retrain larger contaminants without clogging the subsequent filtration module. Brackish water dissociable ions can be mitigated with multiple deionization filter modules. Noxious taste and smells can be mitigated with redundant carbon containing modules. Addition of power to the system can enable incorporation of propulsion mechanisms, indicators for flow or flow control and sensors. Power supplies can be derived from self-contained electrical power sources such as batteries; external electrical power from grid sources, solar or power generators; mechanical power generation via spring actuated components or hand pumping; or other external power sources. Propulsion mechanisms include, but are not limited to, pumping or vacuum components. Indicators could include, but are not limited to, flow volume measurement or flow rate measurement. Control mechanisms could include, but are not limited to, shut-off valves or pressure reduction mechanisms. Sensors could include, but are not limited to: ion measurement, to identify the concentration of dissolved solids; specific ion concentration, to identify selective ion concentrations; biological or organic carbon measurement, to identify the presence or concentration of organic chemicals, biologicals, bacteria or vims; and pH measurement.

[0051] Pretreatment of source water within the water reservoir can enhance system purification capabilities. Use of flocculants can induce aggregation of particulates, which when matched with a mesh prefilter can prevent subsequent clogging of downstream modules.

[0052] Torturous path extension of the path of flow within a chemical purification module can be achieved by spiral flow through the purification bed. The spiral flow can be achieved with conveyer screw insert within the module directing flow laterally rather than axially. In this manner the time of contact and length of exposure to the purification bed can be roughly doubled within the same height module housing.

[0053] The female threaded interconnects on the inlet of modules can thread directly onto a source water bag with a male threaded terminal fitment that is the reciprocal of the inlet. Alternately, a male threaded outlet of a module can be threaded on a female threaded inlet fitment on a collection bag or other means of collection. Alternatively, male by male or female by female threaded or bayonet inserts can be used to interconnect modules with reciprocal interconnects or other fitments with reciprocal, terminal interconnects, such as source water bags or collection bags. A male threaded fitment on a source water bag could be attached to a male threaded module attachment via a female by female threaded interim fitting. Inversely, a female threaded fitment could be attached to a female threaded module fitting via a male by male threaded fitting.

[0054] An alternative means of containment of purification beds or contained filtration mechanisms is enclosure of these subcomponents into cartridges or soft-sided pouches that allow interchange of purification components or filter components within modules. Augmentation of purified fluids with dissolution of dry soluble agents from modules containing these reagents to produce nutritional or therapeutic fluids in remote settings.

[0055] Again, the various modules are interconnectable by reciprocal interconnects that enable stacking of multiple modules. Each module may contain different functional capabilities to accomplish any form or level of contaminant mitigation that could be required. The terminal interconnects enable the modules to be used to form either static or portable systems. For static use, the terminal connection can be attached to a source water reservoir to provide head pressure to drive flow. For mobile use, the terminal interconnects allow insertion of the system between a source water bladder and a bite tube.

[0056] The ability to easily connect and disconnect module housings enables the specific modules to be changed as well as the order in which the modules are employed to be changed. For example, in certain applications it is desirable to filter the water first with a carbon filter and/or a deionizer resin prior to exposing the hollow fiber bundle to the water. In other applications, it is desirable to filter the water with a hollow fiber bundle first. The modularity of the disclosed filter systems enables the filter to be custom-designed for each application.

[0057] While only certain embodiments have been set forth, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure and the appended claims.

Claims

CLAIMS:

1. A modular water filtration system comprising:

an inlet housing comprising a proximal end detachably and sealably connected to a water source and a distal end for detachably and sealably connecting the inlet housing to a first module housing,

the first module housing comprising a proximal end detachably and sealably connected to the distal end of the inlet housing, the first module housing further comprising a distal end and a first restraint disposed between the proximal end distal ends of the first module housing,

the distal end of the first module housing being detachably and sealably connected to an end module, the end module comprising an outlet for the passage of filtered water,

the system further comprising a first filtration stage trapped between the first restraint and the inlet housing and a second filtration stage trapped between the first restraint and the end module,

the first filtration stage being selected from the group consisting of a prefilter mesh, a hollow fiber bundle, a bed of granular carbon, a bed of granular carbon treated with styrene divinylbenzene, and a bed styrene divinylbenzene beads, and

the second filtration stage being selected from the group consisting of a hollow fiber bundle, a bed of granular carbon, a bed of granular carbon treated with styrene divinylbenzene, and a bed styrene divinylbenzene beads.

2. The system of claim 1 wherein a prefϊlter mesh is trapped between the first filtration stage and the inlet housing.

3. The system of claim 1 further comprising a third filtration stage trapped between the second filtration stage and the end module, the third filtration stage being selected from the group consisting of a hollow fiber bundle, a bed of granular carbon, a bed of granular carbon treated with styrene divinylbenzene, and a bed styrene divinylbenzene beads.

4. The system of claim 1 wherein the end module comprises

a second module housing comprising a proximal end detachably and sealably connected to the distal end of the first module housing, the second module housing further comprising a distal end and a second restraint disposed between the proximal end distal ends of the second module housing,

the system further comprising a third filtration stage disposed between the second restraint and the distal end of the second module housing,

the third filtration stage being selected from the group consisting of a hollow fiber bundle, a bed of granular carbon, a bed of granular carbon treated with styrene divinylbenzene, and a bed styrene divinylbenzene beads.

5. The system of claim 4 wherein the distal end of the second module housing is sealably and detachably connected to an end cap that detachably and sealably connected to a dispense conduit.

6. The system of claim 4 wherein the end module further comprises

a third module housing comprising a proximal end detachably and sealably connected to the distal end of the second module housing, the third module housing further comprising a distal end and a third restraint disposed between the proximal end distal ends of the third module housing,

the system further comprising a fourth filtration stage disposed between the third restraint and the distal end of the third module housing,

7. The system of claim 4 wherein the distal end of the third module housing is sealably and detachably connected to an end cap that detachably and sealably connected to a dispense conduit.

8. The system of claim 1 wherein the hollow fiber bundle comprises hydrophilic fibers and hydrophobic fibers.

9. The system of claim 8 wherein the hydrophilic fibers have a pore size ranging from about 0.005 to about 0.4 μm,

10. The system of claim 9 wherein the hydrophilic fibers are fabricated one of polysulfone or polyethersulfone and the hydrophobic fibers are made from polypropylene or an equivalent.

1 1 . The system of claim 1 wherein at least one of the modules comprises at least one anti-microbial agent selected from the group consisting of immobilized halogens, iodinated resins, brominated resins, silver impregnated carbon, silver impregnated resin, and combinations thereof.

12. A modular water filtration system comprising:

an inlet housing comprising a proximal end detachably and sealably connected to a water source and a distal end for threadably connecting the inlet housing to a first module housing, the first module housing comprising a proximal end threadably connected to the distal end of the inlet housing, the first module housing further comprising a distal end and a first restraint disposed between the proximal end distal ends of the first module housing and perpendicular to an axis of the first housing,

the distal end of the first module housing being threadably connected to an end module, the end module comprising an outlet for the passage of filtered water,

13. The system of claim 12 wherein a prefilter mesh is trapped between the first filtration stage and the inlet housing.

14. The system of claim 12 further comprising a third filtration stage trapped between the second filtration stage and the end module, the third filtration stage being selected from the group consisting of a hollow fiber bundle, a bed of granular carbon, a bed of granular carbon treated with styrene divinylbenzene, and a bed styrene divinylbenzene beads.

15. The system of claim 12 wherein the end module comprises

a second module housing comprising a proximal end threadably connected to the distal end of the first module housing, the second module housing further comprising a distal end and a second restraint disposed between the proximal end distal ends of the second module housing,

16. The system of claim 15 wherein the distal end of the second module housing is threadably connected to an end cap that detachably and sealably connected to a dispense conduit.

17. The system of claim 16 wherein the end module further comprises a third module housing comprising a proximal end threadably connected to the distal end of the second module housing, the third module housing further comprising a distal end and a third restraint disposed between the proximal end distal ends of the third module housing,

18. The system of claim 17 wherein at least one of the modules comprises at least one anti-microbial agent selected from the group consisting of immobilized halogens, iodinated resins, brominated resins, silver impregnated carbon, silver impregnated resin, and combinations thereof.

19. The system of claim 12 wherein the hollow fiber bundle comprises hydrophilic fibers and hydrophobic fibers.

20. The system of claim 19 wherein the hydrophilic fibers have a pore size ranging from about 0.005 to about 0.4 μm.