WO1999033539A1

WO1999033539A1 - Water purification filter

Info

Publication number: WO1999033539A1
Application number: PCT/US1998/026317
Authority: WO
Inventors: Judith Y. Ikawa
Original assignee: The Clorox Company
Priority date: 1997-12-30
Filing date: 1998-12-11
Publication date: 1999-07-08
Also published as: AU1817199A

Abstract

The present invention provides a composition for the purification of water comprised of components that effectively remove a wide spectrum of contaminants from the water. The invention is particularly useful in that it extends the efffective lifespan of water filters containing the composition compared to presently available water filter compositions. The composition is comprised of an effective amount of absorbent granules, an ion exchange resin, and a biostatic-coated carbon material. The invention provides structural elements for use of the composition, and methods for treating the water with the composition.

Description

WATER PURIFICATION FILTER TECHNICAL FIELD This invention relates generally to the field of water purification, and particularly relates to methods, materials and devices for use in purifying water.

BACKGROUND OF THE INVENTION

Activated carbon has been used for decades in water filters as a means of improving the quality of water by removing objectionable tastes and odors and particles such as dirt, rust, and sand. Activated carbon filters are also capable of producing water free from microbial contamination for a period of time, until the buildup of organic material and concentration of microorganisms combine to foster growth and shedding of the microorganisms into the treated water. Although such filtration assemblies utilizing activated carbon remove many undesirable materials, such as chlorine, metals (e.g. iron, lead, copper, manganese and aluminum), and bacteria, the filtrates are not as effective against a broader range of metals and microorganisms. Many activated carbon filters give unsatisfactory removal of total chlorine, trihalomethanes, total organic carbon, and certain metals.

Adsorbent materials have been used in conjunction with activated carbon filtering methods in attempts to further purify water. These materials cannot be easily integrated into a single filtration composition, however, since they present certain limitations with respect to compatibility limitations with other components of filter systems. For example, the use of bentonite clays and attapulgite clays in water filtration is well known in the art. Both bentonite clay and attapulgite clay are known to have exchangeable cations (Mg, Ca and NH₄) in their lattice structure that would be expected to interfere with the functioning of other components. In addition, both attapulgite and bentonite clays develop negative charges, and would be expected to repulse rather than adsorb negatively charged ions due to forces between like charged materials.

Both the microbial and chemical removal efficiency of currently available activated carbon filters deteriorates with continued use of the filter. The length of time that a filter has been in service is largely determinative of the efficacy of such a device in improving the quality of the treated water. The addition of a bacteriostatic agent, such as silver, to the activated carbon increases the lifespan of such activated carbon filters, but such filters .are still subject to colonization by various forms of microorganisms after continuous use. Consumers using such filtering processes have no readily available means to determine when the filter's capacity for purification is exceeded. The quality of water after treatment through a filter in which the purification capacity has been exceeded is oftentimes worse that the quality of the initial, untreated water.

There is a need in the field for a water purification composition that results in an improved microbial and chemical quality of the treated water. There is also a need for a composition that will extend the effective lifespan of a water purification filter. Such a filter, by having an extended lifespan, will add convenience to the consumer because it requires less frequent replacement. The extended lifespan will also aid in protecting consumers from the adverse health effects of using a contaminated water filter device.

SUMMARY OF THE INVENTION

Compositions for use in purifying water are disclosed along with a methods for use of such compositions in the process of water purification. Also disclosed are structural embodiments for utilization of the composition in the practice of the methods.

It is a primary object of the invention to address the need in the .art discussed above by providing a water purification filter that will remove impurities from the purified product more efficiently.

Another object of the invention is to produce a water purification filter that will reduce the amount of metals and organic contaminants found in the purified product.

Another object of the invention is to produce a water purification filter that will reduce the amount of microorganisms in the purified product.

One advantage of this system is that it is able to increase the efficiency of removal of impurities compared to filters presently used in the art.

Another advantage of this filter is it will increase the usable life of the filter compared to filters presently used in the art. In one embodiment, the invention features a composition for purifying water comprised of an effective amount of absorbent granules, an ion exchange resin and a biostatic-coated carbon material.

In another embodiment, the invention features a composition for purifying water comprised of an effective amount of biocide-treated absorbent granules, an ion exchange resin, and a biostatic-coated carbon material.

One feature of the invention is a water filter cartridge comprised of a structure defining .an interior cavity having an upper inlet and a lower inlet through which water can pass and a filtration bed positioned within the cavity between the upper inlet and the lower inlet. The filtration bed is comprised of an effective amount of absorbent granules, an ion exchange resin, .and a biostatic-coated carbon material.

Another feature of the invention is the use of a water filter cartridge in a water purifying device.

In a first embodiment, the water purifying device is comprised of a water filter cartridge, a top chamber connected to the device above the filter cartridge with .an opening at the bottom for transferal of water to the filter cartridge, a bottom chamber connected to the device below the filter cartridge having an opening for collecting treated water exiting the filter cartridge, and a side chamber adjacent to the filter cartridge and connected to the bottom chamber to access the treated water. In another embodiment, the invention features a water purifying device comprised of a water filter cartridge, a chamber containing the filter cartridge having an opening in the forward and back portions of the chamber for the passage of water, and a means for attachment of the back portion of the chamber to a water pressure system. The water is purified when the water pressure causes water to enter the back portion of the chamber, flow through the filter cartridge, and exit the chamber through the forward portion of the chamber, exposing the water to the materials in the filter devices.

Another feature of the invention provides a method for the treating water to remove metals and organic contaminants from the water. The method comprises exposing the water to a filter containing biocide-treated absorbent granules, an ion exchange resin and a biostatic-coated carbon material, and providing a means for passing the water through the filter. The exposure of the water to the filter will result in the adsorption of contaminants to the absorbent granules.

Another feature of the invention provides a method for treating water to inhibit growth of microorganisms in the filter. The method comprises exposing the water to a filter containing biocide-treated absorbent granules, an ion exchange resin and a biostatic-coated carbon material, and providing a means for passing the water through the filter. The exposure of the water to the filter will result in the killing or inhibition of microorganisms present in the untreated water.

BRIEF DESCRIPTION OF THE FIGURES

Figures 1 A -and IB are two views of the water filter cartridge as it is placed in the cylindrical holding cup of the gravity-driven water device. Figure 1 A is the filter cartridge as viewed from above the device. Figure IB is a cross-sectional view illustrating the filter cartridge as it sits in the holding cup. Figure 2 is a general side view of the gravity-driven water purification device.

Figure 3 is a general side view of the pressure-driven water purification device.

DETAILED DESCRIPTION OF THE INVENTION Before the present invention is described in detail, it is to be understood that this invention is not limited to the particular use or methodology described. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims.

Use in the specification and appended claims of the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a filter" in a device includes the presence of a plurality of filters within a device, reference to "an ion exchange resin" includes mixtures of such resins, reference to "a plant material" includes mixtures of two or more plant materials, and the like.

The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although any methodology or materials similar to or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are hereby incorporated by reference for the purpose of disclosing and describing the particular materials and methodologies for which the reference was cited.

DEFINITIONS An "adsorbent granule" is a chemically inert particle of a material having a low or medium sorptive capacity. For example, the preferred sorptive capacity is approximately 0.85 ml/g water absorbency, 0.64 ml/g oil absorbency, with a corresponding attrition resistance of 99.0%

The term "effective amount" as used herein refers to a sufficient amount of a material to achieve a desired result. For example, in terms of water filtration, an "effective amount" may be sufficient material in a filter to reduce the bacterial content of water treated to below a certain desired concentration. In an additional example, an "effective amount" of a material in a filter may reduce the concentration of a particular metal in the purified water product to below a certain concentration.

The terms "biocide" or "biocidic" as used herein refers to any substance that inhibits the growth of microorganisms such as bacteria, molds, slimes, fungi, etc. Biocides include, but .are not limited to, quaternary ammonium salts, halogen-releasing compounds, aldehyde derivatives, halogenated styrenes, thiocyanates, carbarnates, azo chlorides, and modified phenols. The preferred biocide is magnesium hydroperoxyacetate (MPHA).

The phrase "biostatic-coated" in reference to the carbon material refers to a coating of the carbon material with a substance that suppresses the growth and colonization of microorganisms, and in particular bacteria, on the carbon material.

The term "slurry" as used herein refers to a particles suspended in an aqueous solution. A "plant material slurry" refers to an aqueous suspension of insoluble plant material Plant material slurry may also include suspended filler substances. "Primary de-inked sludge" is a slurry of waste material from recycled newsprint and other papers. Primary de-inked sludge normally has a content of between 40-90% plant fibers and 10-60% filler. De-inked paper sludge in its raw form is approximately 90% water, and may contain suspended filler substances.

A "filler substance" is a substance present in the slurry that affect parameters of the slurry such as color (e.g. dyes or titanium dioxide) or density (e.g. kaolin clay or barytes). The filler substance does not significantly affect the substantially inert nature of the resulting absorbent granule.

The term "incorporating" as used herein means including as a functional element of a device or apparatus. Incorporation in a filter may be permanent, as in the case of a nonremovable filter cartridge in a disposable water purification device, or temporary, e.g. a replaceable filter cartridge in a permanent or semi-permanent water purification device.

Filtration composition

The filtration composition contained within the filtration bed is comprised of an effective amount of absorbent granules, an ion exchange resin, and an activated carbon material. The water is passed through the filtration composition to eliminate undesirable contaminants present in the water. One aspect of the present invention comprises a single composition that is capable of removing numerous cont.amin.ants from the water with a single treatment.

The activated carbon functions to remove organic compounds of health concern and to remove undesirable contaminants that affect the taste and odor of the water. The activated carbon can be coated with a biostatic agent, preferably zinc or copper, more preferably silver. The carbon removes impurities by acting as an adsorbent; most organic materials, including natural, synthetic, disinfection by-products .and volatile organics. Taste, odor and color producing organic compounds are readily adsorbed by activated carbon. Certain inorganic materials having adverse health effects, such as mercury, lead, arsenic, chlorine and chlorine by-products are also be removed by adsorption to activated carbon. The silver coating releases silver ions into the water, not exceeding 50 μg/liter in effluent. The silver works as a biostatic agent to prevent the build-up of microorganisms on the activated carbon.

The ion exchange resin is a mixture of synthetic anion .and cation exchange resins. Water passed through the mixed bed of synthetic resins is deionized, since cations have been replaced by hydrogen ions and anions by hydroxyl ions. Water passed through such an ion exchange resin depleted of mineral contaminants, and if the efficiency of the ion exchange is very great the treated water will have a quality comparable with distilled water. This exchanger has the advantage of producing water with resistance approximating theoretical perfection and a more balanced and consistent pH ranging between 7.0 to 7.5. The absorbent granules used in the filtration composition are derived from any of a number of fibrous plant materials, including sugar beet slurry, sugar cane slurry, citrus pulp slurry, grain slurry, and potato slurry. These materials may be in a variety of forms, including primary sulfite pulp, secondary sulfite pulp, primary sulfate pulp, secondary sulfate pulp, paper sludge. Preferably, the adsorbent granules are derived from de-inked fiber sludge. The composition of the filter in the preferred embodiment of the invention preferably contains

50% adsorbent granules, and more preferably 1-20% adsorbent granules.

In one embodiment of the invention, the adsorbent granule is treated with a biocide before being added to the water purifying composition. The biocidic agent may either be incorporated into the granule during production of the granule, or the granule may be treated with a biocide subsequent to its production. US Patent 5,019,564 is herein incorporated by reference to describe the methods by which the biocide is integrated with the granule. The biocide used may be quaternary ammonium salts, halogen-releasing compounds, aldehyde derivatives, halogenated styrenes, thiocyanates, carbarnates, azo chlorides, or modified phenols. Preferably, the biocide is MPHA. The adsorbent granules of the present invention are chemically neutral to a wide range of chemicals, and thus the biocides will retain much of their activity and be immobilized. Exposure to a granule treated with the biocidic agent will allow the water to be purified without releasing the biocide directly into the water. The potential need for a deactivator of the biocide is thus eliminated.

Filtration Cartridge

The composition of the present invention is contained within a filtration cartridge for easy use of the composition in the water purification process. Since the composition is contained within a single cartridge, it can easily and conveniently be replaced when the purifying capacity of the composition becomes exhausted. Alternatively, the cartridge may be an integral part of a filter device, in which case the entire device is replaced once the filtration composition has exhausted its efficacy. The first embodiment of the water filter cartridge 1 is constructed to be removably inserted into a cylindrical holding cup 2. A more detailed view of the filter cartridge is shown in Figs. 1 A .and IB. The filter cartridge is generally cylindrical in nature, and circular in cross-section (See Fig. 1 A), with the circumference of the cartridge being larger at the top of the cartridge than at the bottom. A covering 3 for the upper inlet of water into the cartridge is constructed of a rigid material with slots 4 through which the water enters the filtration composition bed 5. The slots in the inlet cover can vary in size depending on the desired rate of flow of the water through the filter cartridge. The inlet cover slots 4 should be arranged such that it provides adequate flow-through of the water, but also allows the water sufficient contact time with the purification composition to allow the purification process to take place.

The filtration bed 5 is contained between the inlet cover and the filter cartridge bottom 6. The filter cartridge bottom is constructed from a water permeable material to allow passage of the purified water pass. Preferably, the material is stainless steel mesh.

The second embodiment of the filter cartridge is a cartridge that is an integral part of the filtration device, i.e., it is permanently attached to the device. Such a filter contains generally the same components as the filter described above. The filtration cartridge would contain a covering for control of the inlet of water into the cartridge, a filtration composition bed, and a filter cartridge bottom. The cartridge could be varied in shape, depending on the nature and use of the device.

Layered filtration composition bed

In one embodiment of the invention, the components of the filter cartridge are layered sequentially for treatment of the water. The water would first be exposed to the biostatic activated carbon to remove suspended solids, organic matter, chlorine, etc. The water would then be exposed to the anion and cation exchange resin as described in Example

1. The prior activated carbon treatment greatly reduces the chance of fouling during the ion exchange process. Finally, the water would contact the adsorbent granules. The adsorbent granules may either be biocide treated, or not, depending on the nature of the water to be purified. Interspersed filter composition bed

In another embodiment of the invention, the components of the purifying composition in the filter cartridge are interspersed, allowing exposure to each of the purifying agents simultaneously. This would be a preferred embodiment for untreated water with a higher concentration of particulate matter, as the particles are not as likely to be deposited in a layer-like fashion, precluding flow of the water through the remaining layers. Since one layer provides simultaneous exposure to each of the purifying agents of the composition, it would also be preferable for extending the period of exposure to a particular purifying agent without significantly slowing the purification process.

EXAMPLES The following examples are put forth so as to provide those of ordinary skill in the art with a complete description of how to make and use the present invention, and are not intended to limit the scope of what is regarded as the invention. Some deviation in the practice of the invention is to be expected. Unless indicated otherwise, parts are parts by weight, temperature is degree centigrade and pressure is at or near atmospheric.

Example 1 : Efficiency Testing of Filters

Three filters are prepared using Biodac cellulosic granules (GranTek, Inc.). For the first filter, adsorbent granules are soaked in a sterile water solution containing 10% magnesium hydroperoxyacetate (MPHA), briefly rinsed in deionized water to remove any unbound MPHA, and air dried. The filter sample is prepared using 4g of the 10% MPHA-treated granules in a first, bottom layer and 65g (approximately 130 ml) of a carbon-ion exchange resin (USA Lot 38-116-6, Drum #25). The resin material contains approximately 160 ppm of silver as a biostatic agent. Filters are then exposed to ultra-sonic sealing and soaked in sterile water. The filters are then used in travel canisters, which are sanitized with 220 ppm bleach and subjected to multiple rinses with sterile water prior to use. The second filter is also prepared using Biodac cellulosic granules. Granules are soaked in a solution containing 5% MPHA dissolved in sterile water, briefly rinsed to remove excess MPHA, and air dried. The filter sample is prepared using 13g of the 5% MPHA granules intermixed with 52g of carbon-ion exchange resin (USA Lot 38-116-6, Drum #25). A third filter is prepared using 65g of the carbon-ion exchange resin. This filter is to serve as a control for determining the efficacy of the filters containing the MPHA-treated Biodac.

The efficiency of each filter in inhibiting microbiological organisms in filter effluent is determined by measuring levels of three bacteria: Pseudomonas aer ginosa (ATCC 15442), Pseudomonas aeruginosa ERC- 1 , .and Pseudomonas flour escens. Filters .are first enumerated for background levels of the organisms by passing 100 ml of sterile water through the filter .and plating the treated water onto sterile petri dishes containing 10 ml of R2A medium, and grown for at least 10 hours at 37°C. Non-sterile tap water is inoculated with a composite of the three bacteria to a concentration of approximately lxl0^4r/Ml of water. 100 ml of the inoculated water is passed through each filter, and the effluent plated at a series of dilutions: 1 :1, 1 :10, 1 :100, and 1:1000. The effluent is also plated onto sterile petri dishes containing 10 ml of R2A medium and grown for at least 10 hours at 37°C. This procedure will be repeated each day for seven consecutive days, and levels of cultured organisms determined for both the sterile and the inoculated water. After one week, a final rinse with sterile distilled water will be sampled to examine an internal build-up of bacteria will be determined.

Example 2: Gravity-driven purification device

The purification device 7 is generally cylindrical in shape, and is comprised of three interconnected chambers: a top chamber 8, into which untreated water is first placed for purification; a bottom chamber 9, which is the holding area for the purified water; and a side chamber 10, which provides access to the purified water without causing the water to flow back through the filter cartridge (Fig. 2). Preferably, the device is constructed from clear plastic or a similar material. A cylindrical holding cup 2 is rigidly attached to the inside wall of the device between the top and bottom chambers. The cylindrical holding cup defines the boundary between the top chamber and the bottom chamber, and at least in part defines the inside wall of the side chamber. A filter cartridge 1 is designed as an insert that is removably inserted in the cylindrical holding cup. The side chamber is oriented such that the treated water can be poured from the bottom chamber, into the side chamber, and through an open spout at the top of the side chamber. A handle 11 for pouring is attached to the device opposite the side chamber to aid in removing the purified water by pouring. Example 3: Pressure-driven purification device

The pressure-driven purification device is located linearly aligned and attached in line with a pressurized water supply (Fig. 3). The device of this invention can be installed generally in stationary water purification situations but can also be adapted for portable use. The device can be conveniently installed, for example, in a kitchen sink faucet with an easy interchange of the entire device once its purifying capabilities have been exhausted.

The purification device 12 is comprised of a cylindrical pipe-like housing 13 that is made of a rigid material, preferably stainless steel. The housing contains a permanently attached filtration cartridge 14. The filtration cartridge is comprised of: a covering 15 for the upper inlet of water having slots to control the flow of the water into the filter; a filtration composition bed 16 containing the components of the filtration composition; and a covering for the outflow of the purified water 17. The filter cartridge bottom is constructed from a water permeable material to allow passage of the purified water pass. Preferably, the material is stainless steel mesh. The back portion of the housing is rigidly connected to an attachment means 18 for removably attaching an inlet tube 19 to the housing. The attachment means tapers to a thinner opening just smaller th.an the circumference of the inlet tube. The inlet tube 19 is connected to the tapered end of the attachment means, and can be easily assembled and disassembled from the water supply without the need of a tool at the time of replacement of the filtration cartridge. The end of the inlet tubing opposite the filter device 20 is connected to a pressurized water supply, such as a sink faucet. This provides the means by which the water is forced through the filtration device. The inlet tubing is preferably made from a flexible material, such as rubber. The flow through the inlet tubing can be controlled through an inlet valve 23 located on the attachment means. The front portion of the housing is connected to a long outlet tubing 21 that serves

■as .an outlet for the purified water. The outlet tubing is preferably made from a flexible material, such as rubber. Such tubing is perm-anently attached to the filter device by a exit piece 22 that connects to the housing, and tapers to the point where the outlet tubing connects to the device. The foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of underst-anding. It is readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claims.

Although the invention has been described with reference to the presently preferred embodiments, it should be understood that various modifications can be made without departing from the spirit of the invention. Accordingly, the invention is limited only by the following claims.

Claims

What is claimed is:

1. A composition for purifying water comprising:

(a) an effective amount of absorbent granules;

(b) ion exchange resin; and

(c) biostatic-coated carbon material.

2. The composition of claim 1, wherein the composition is approximately 50% adsorbent granules.

3. The composition of claim 1, wherein the absorbent granules are derived from a plant material.

4. The composition of claim 3, wherein the absorbent granules are derived from one more plant materials selected from the group consisting of primary sulfite pulp, secondary sulfite pulp, primary sulfate pulp, secondary sulfate pulp, paper sludge, and de-inked fiber sludge, or any combination thereof.

5. The composition of claim 3, wherein the absorbent granules are derived from one or more plant material slurries selected from the group consisting of sugar beet slurry, sugar cane slurry, citrus pulp slurry, grain slurry, .and potato slurry, or .any combination thereof.

6. The composition of claim 1, wherein the carbon material is coated with a biostatic material selected from the group consisting of silver, zinc and copper.

7. A composition for purifying water comprising:

(a) an effective amount of biocide-treated absorbent granules;

(b) ion exchange resin; and

(c) a biostatic-coated carbon material.

8. The composition of claim 7 wherein the composition is approximately 1-50% biocide- treated absorbent granules.

9. The composition of claim 7, wherein the biocide-treated absorbent granules derived from a plant material.

10. The composition of claim 9, wherein the absorbent granules are derived from one or more plant materials selected from the group consisting of primary sulfite pulp, secondary sulfite pulp, primary sulfate pulp, secondary sulfate pulp, paper sludge, and de-inked fiber sludge, or any combination thereof.

11. The composition of claim 9, wherein the absorbent granules are derived from one or more plant material slurries selected from the group consisting of sugar beet slurry, sugar cane slurry, citrus pulp slurry, grain slurry, and potato slurry, or any combination thereof.

12. The composition of claim 7, wherein the carbon material is coated with a material selected from the group consisting of silver, zinc and copper.

13. The composition of claim 7, wherein the biocide used to treat the absorbent granules is selected from the group consisting of quaternary ammonium salts, halogen-releasing compounds, aldehyde derivatives, halogenated styrenes, thiocy-anates, carbarmates, azo chlorides, and modified phenols, or any combination thereof.

14. The composition of claim 7, wherein the biocide used to treat the absorbent granules is magnesium hydroperoxyacetate.

15. A water filter cartridge comprising:

(a) a structure defining an interior cavity having an upper inlet and a lower inlet through which water can pass; and

(b) a filtration bed positioned within the cavity between the upper inlet and the lower inlet comprised of an effective amount of absorbent granules, an ion exchange resin, and a biostatic-coated carbon material.

16. The filter cartridge of claim 15, wherein the materials comprising the filtration bed .are layered.

17. The filter cartridge of claim 15, wherein the materials comprising the filtration bed are interspersed.

18. The filter cartridge of claim 15, wherein the adsorbent granules are biocide-treated.

19. A water purifying device, comprising:

(a) the filter cartridge of claim 15;

(b) an upper chamber connected to the device above the filter cartridge, the chamber having an opening at the bottom for transferal of water to the filter cartridge;

(c) a lower chamber connected to the device below the filter cartridge for storing treated water, the bottom chamber having an opening for collecting treated water exiting filter cartridge; and

(d) a side chamber adjacent to the filter cartridge and connected to the bottom chamber to access the treated water.

20. The water purifying device of Claim 19, wherein the filter cartridge is replaceable.

21. A water purifying device, comprising:

(a) the filter cartridge of claim 15;

(b) a chamber containing the filter cartridge, the forward and back portions of the chamber each defining an opening for the passage of water; and

(c) a means for attachment of the back portion of the chamber to a water pressure system; wherein the water pressure causes water to enter the back portion of the chamber, flow through the filter cartridge, and exit the chamber through the forward portion of the chamber, thereby purifying the water by exposure to the materials in the filter device.

22. The water purifying device of claim 21 wherein the filter cartridge is replaceable.

23. A method for the treatment of water to remove metals from the water comprising exposing the water to a filter comprising biocide-treated absorbent granules, an ion exchange resin and a biostatic-coated carbon material, and providing a means for passing the water through the filter, wherein the exposure of the water to the filter will result in the adsorption of metals and organic contaminants to the absorbent granules.

24. A method for treating water comprising exposing the water to a filter comprising biocide-treated absorbent granules, an ion exchange resin and a biostatic-coated carbon material, and providing a means for passing the water through the filter, wherein the exposure of the water to the filter will result in the killing or inhibition of microorganisms present h untreated water.

25. The method of claim 24, wherein the biocide used to treat the absorbent granules is selected from the group consisting of quaternary ammonium salts, halogen-releasing compounds, aldehyde derivatives, halogenated styrenes, thiocy-anates, carbamates, azo chlorides, and modified phenols.

26. The method of claim 24, wherein the biocide used to treat the absorbent granules is magnesium hydroperoxy acetate.