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WO1998004335A1 - Procede d'utilisation d'un filtre modifie par une charge cationique - Google Patents

Procede d'utilisation d'un filtre modifie par une charge cationique Download PDF

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Publication number
WO1998004335A1
WO1998004335A1 PCT/US1997/010722 US9710722W WO9804335A1 WO 1998004335 A1 WO1998004335 A1 WO 1998004335A1 US 9710722 W US9710722 W US 9710722W WO 9804335 A1 WO9804335 A1 WO 9804335A1
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WO
WIPO (PCT)
Prior art keywords
filter
charge
aqueous liquid
reduction
vibrio cholerae
Prior art date
Application number
PCT/US1997/010722
Other languages
English (en)
Inventor
Dennis Stein Everhart
Elizabeth Deibler Gadsby
Rosann Marie Kaylor
Kristi Lynn Kiick-Fischer
Original Assignee
Kimberly-Clark Worldwide, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kimberly-Clark Worldwide, Inc. filed Critical Kimberly-Clark Worldwide, Inc.
Priority to AU34059/97A priority Critical patent/AU3405997A/en
Publication of WO1998004335A1 publication Critical patent/WO1998004335A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
    • A61L2/0005—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor for pharmaceuticals, biologicals or living parts
    • A61L2/0011—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor for pharmaceuticals, biologicals or living parts using physical methods
    • A61L2/0017—Filtration
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
    • A61L2/02—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using physical phenomena
    • A61L2/022—Filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/18—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being cellulose or derivatives thereof

Definitions

  • This invention relates to a method of filtering aqueous liquids.
  • Apertured films, woven fabrics and nonwoven materials have been used as filter sheets for removing or separating particles from liquids.
  • methods of filtering liquids that utilize such filter sheets rely on some form of mechanical straining or physical entrapment that can present limitations when the size of the particle to be removed is very small, especially particles of less than one micron in diameter.
  • filters have been developed with modified surface charge characteristics to capture and adsorb particles by electrokinetic interaction between the filter surface and particles contained in an aqueous liquid.
  • Some filters have been used in processes reported to be effective in removing specific virus particles and pyrogens. The reported literature appears to describe use of such charge-modified filter materials only for capturing and concentrating waterborne enteric viruses for sampling large water sources (e.g., lakes, rivers, effluent).
  • One phenomena observed with some filters having modified surface charge characteristics is that the filters have different filtration efficiencies for different types of particles and/or organisms, such as, for example, different types of virus. That is, some filters having modified surface charges provide acceptable removal of some types of organisms (e.g., some types of virus) but not others. The nature of this affinity appears to be difficult to predict. In some cases, the affinity exists under only carefully controlled circumstances.
  • chemical charge modifier refers to polymeric material capable of coating a substrate and providing a cationic charge site.
  • Chemical charge modifiers may be cationic polymers such as, for example, quaternary amine containing cationic resins, aliphatic polyamines having at least one primary amine or at least two secondary amines, and the like. It is contemplated that chemical charge modifiers may be cationic polymer systems composed of a primary polymer material and a secondary polymer material.
  • the cationic polymer system may be composed of a primary polymer material such as polyamine epichlorohydrin and a secondary polymer material such as tetraethylene pentamine.
  • Exemplary chemical charge modifiers may have a positive charge and, when present in a liquid having a dielectric constant sufficient for separate charged particles to exist, can be incorporated, coated or adsorbed onto a substrate to modify the coating so that cationic species and/or positively charged particles are present at the surface of the coating under the appropriate conditions.
  • chemically charge-modified refers to the incorporation of chemical charge modifiers (e.g., cationic polymers) onto a substrate.
  • charge modification occurs when the chemical charge coated substrate is in contact with aqueous liquid under appropriate conditions so that cationic species and/or positively charged particles are present on the surface of the coating.
  • waterborne pathogens refers to microorganisms existing in water or aqueous liquids that are capable of causing disease.
  • waterborne pathogens are microorganisms greater than 0.1 micron in size and excludes the class of pathogens commonly referred to as "viruses.”
  • Exemplary waterborne pathogens include, but are not limited to, Vibrio cholerae, Eshcerichia coli. Salmonella tvohimurium, Shiaella flexineri, Campylobacter ieiuni, Pseudomonas aeruginosa. Giardia lamblia, Crvotosporidium parvum, and Staphylococcus aureus.
  • the term "adsorbed” refers to a type of adhesion which takes place at the surface of a solid in contact with another medium (e.g., a liquid), resulting in the accumulation or increased concentration of molecules from that medium in the immediate vicinity of the surface.
  • nonwoven web refers to a web that has a structure of individual fibers or filaments which are interlaid, but not in an identifiable repeating manner. Nonwoven webs have been, in the past, formed by a variety of processes known to those skilled in the art such as, for example, meltblowing, spunbonding, wet-forming and various bonded carded web processes.
  • sheet refers to a material that can be a woven fabric, knit fabric, nonwoven fabric or film-like material (e.g., an apertured film-like material).
  • the term "consisting essentially of does not exclude the presence of additional materials which do not significantly affect the desired characteristics of a given composition or product.
  • Exemplary materials of this sort would include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, particuiates or materials added to enhance processability of a composition.
  • the problems described above are addressed by the present invention which is directed to a method of removing a substantial portion of waterborne pathogens from an aqueous liquid contaminated with such waterborne pathogens.
  • the method includes the steps of passing the contaminated aqueous liquid through a chemically charge-modified filter composed of: 1) a filter sheet having a plurality of individual exposed cellulose fibers and silica based filter materials selected from silica particuiates and siliceous fibers; and 2) cationic chemical charge modifiers coated on or bonded to surfaces of the filter sheet.
  • the chemical charge modifiers include: 1) a primary charge modifier composed of a water soluble organic polymer capable of being adsorbed onto the filter sheet and having a molecular weight of greater than about 1000, each monomer of the polymer having at least one epoxide group capable of bonding to the individual exposed surfaces of the filter sheet and also having at least one quaternary ammonium group; and 2) a secondary charge modifier bonded to a portion of the epoxy groups on the organic polymer, wherein the secondary charge modifying agent is an aliphatic polyamine having at least one primary amine or at least two secondary amines.
  • the waterborne pathogens may be greater than about 0.1 micron in size.
  • the waterborne pathogens may be selected from Vibrio cholenae. E. coli. S. typhimurium. S. flexineri. C. ieiuni. R aeniQinosa, G. lamblia, C. parvum and S. aureus.
  • the reduction of Vibrio cholerae is desirably greater than a log 3 reduction.
  • the reduction of Vibrio cholerae is desirably greater than a log 5 reduction.
  • Acceptable reductions of Vibrio cholerae may be achieved under a variety of conditions.
  • satisfactory reductions of Vibrio cholerae may be achieved when the waterborne pathogen contaminated aqueous liquid has a pH ranging from about 5 to about 9.
  • the chemical charge modifiers may be cationic polymers such as, for example, quaternary amine containing cationic resins, aliphatic polyamines having at least one primary amine or at least two secondary amines, and the like.
  • the chemical charge modifiers may be cationic polymer systems composed of a primary polymer material and a secondary polymer material.
  • the cationic polymer system may be composed of a primary polymer material such as polyamine epichlorohydrin and a secondary polymer material such as tetraethylene pentamine.
  • the filter sheet is desirably composed of cellulose fiber and silica based filter materials selected from silica particuiates and siliceous fibers (e.g., glass fibers).
  • the filter sheet may contain cellulose fiber in combination with some other fibrous or particulate material.
  • exemplary fibrous materials include meltblown fibers, spunbond filaments and/or various staple fibers.
  • the chemically charge-modified filter may have a basis weight of from about 6 to about 400 grams per square meter (gsm).
  • the chemically charge-modified filter may have a basis weight of from about 12 to about 250 grams per square meter.
  • the chemically charge-modified sheet may have a basis weight of from about 17 to about 102 grams per square meter.
  • the present invention encompasses a method of removing waterborne pathogens from aqueous liquid utilizing a multi-layer filter material including at least two layers of the chemically charge-modified filter described above.
  • the present invention also encompasses a method utilizing a multi-layer material including at least one layer of the chemically charge- modified filter described above and at least one other layer.
  • the other layer may be selected from woven fabrics, knit fabrics, bonded carded webs, continuous spunbond filament webs, meltblown fiber webs, films, apertured films, and combinations thereof.
  • the present invention also encompasses a method of removing waterborne pathogens from aqueous liquid utilizing the chemically charge-modified filter described above in a three- dimensional form or shape such as, for example, a tube, cylinder, cone, cube, sphere or the like.
  • the method of the present invention described above further encompasses a method of removing a substantial portion of waterborne pathogens greater than 0.1 micron in size from water contaminated with such waterborne pathogens to produce potable water.
  • the method includes the step of passing the contaminated water through the chemically charge- modified filter described above so that a substantial portion of the waterborne pathogens greater than 0.1 micron in size is adsorbed onto the chemically charge-modified filter.
  • FIG. 1 is a micrograph of an exemplary chemically charge-modified filter material.
  • the present invention is directed to a method of removing a substantial portion of waterborne pathogens from an aqueous liquid contaminated with such waterborne pathogens.
  • the method includes the steps of passing the contaminated aqueous liquid through a chemically charge-modified filter composed of: 1) a filter sheet having a plurality of individual exposed cellulose fibers and silica based filter materials selected from silica particuiates and siliceous fibers; and 2) cationic chemical charge modifiers coated on surfaces of the filter sheet.
  • the filter sheet is desirably composed of cellulose fiber and silica based filter materials selected from silica particuiates and siliceous fibers (e.g., glass fibers).
  • the cellulose fibers may be wood pulp having a diameter ranging from about 6 to about 60 microns and lengths ranging from about 0.85 to about 6.5 millimeters. It is desirable to have greater than about 50%, by weight, of the filter sheet be particulate materials. Suitable siliceous particuiates include, for example, clays, talc, diatomaceous earth or the like. Siliceous fibers (e.g., glass fibers) may be used alone or may be mixed with the siliceous particuiates.
  • the filter sheet may contain cellulose fiber in combination with some other fibrous or particulate material.
  • exemplary fibrous materials include meltblown fibers, spunbond filaments and/or various natural and/or synthetic fibers.
  • the fibrous materials are meltblown fibers, they may include meltblown microfibers.
  • the fibrous materials may be formed from thermoplastic polymers or thermoset polymers. If the fibrous materials are formed from a polyolefin, the polyolefin may be polyethylene, polypropylene, polybutene, ethylene copolymers, propylene copolymers and butene copolymers.
  • the fibers and/or filaments may be formed from blends that contain various pigments, additives, strengthening agents, flow modifiers and the like. Such fabrics are described in U.S. Patent Nos. 4,041,203, 4,374,888, and 4,753,843, the contents of which are incorporated herein by reference.
  • the filter sheet may be formed by adding fibers and/or particuiates to the gas stream in which meltblown fibers are carried so that an intimate entangled commingling of meltblown fibers and other materials, e.g., wood pulp, staple fibers and particuiates such as, for example, activated carbon, silica particuiates, clays, or the like, occurs prior to collection of the meltblown fibers upon a collecting device to form a coherent web of randomly dispersed meltblown fibers and other materials such as disclosed in U.S. Patent Nos. 4,100,324, and 5,350,624, the disclosure of which is hereby incorporated by reference.
  • meltblown fibers and other materials e.g., wood pulp, staple fibers and particuiates such as, for example, activated carbon, silica particuiates, clays, or the like
  • the fibrous material in the filter sheet may be joined by interfiber bonding to form a coherent web structure.
  • Interfiber bonding may be produced by entanglement between individual meltblown fibers, carded fibers, spunbond filaments and/or other fibrous materials. Some fiber entangling is inherent in the meltblown process, bonding- carding process and/or spunbond process but may be generated or increased by processes such as, for example, hydraulic entangling or needlepunching. Alternatively and/or additionally a bonding agent may be used to increase the desired bonding. If at least a portion of the fibrous material in the filter sheet is cellulosic fibrous material, some interfiber bonding may be attributable to "paper" bonding.
  • the filter sheet may have a basis weight ranging from about 6 gsm to about 400 gsm.
  • the filter sheet may have a basis weight ranging from about 12 gsm to about 250 gsm.
  • the filter sheet may have a basis weight ranging from about 17 gsm to about 102 gsm. It is contemplated that, after processing, any number of treated filter sheets may be joined together or treated filter sheets may be joined to other materials to form a consolidated material that may have a basis weight within the range of 6 gsm to 400 gsm or even greater (e.g., 400 gsm or more).
  • the chemical charge modifiers include: 1) a primary charge modifier composed of a water soluble organic polymer capable of being adsorbed onto the filter sheet and having a molecular weight of greater than about 1000, each monomer of the polymer having at least one epoxide group capable of bonding to (or coating) the individual exposed surfaces of the filter sheet and also having at least one quaternary ammonium group; and 2) a secondary charge modifier bonded to a portion of the epoxy groups on the organic polymer, wherein the secondary charge modifying agent is an aliphatic polyamine having at least one primary amine or at least two secondary amines; a filter sheet having a plurality of individual exposed surfaces.
  • a primary charge modifier composed of a water soluble organic polymer capable of being adsorbed onto the filter sheet and having a molecular weight of greater than about 1000, each monomer of the polymer having at least one epoxide group capable of bonding to (or coating) the individual exposed surfaces of the filter sheet and also having at least one quaternary ammonium group
  • Exemplary cationic polymers include, but are not limited to, quaternary amine containing cationic resins, aliphatic polyamines having at least one primary amine or at least two secondary amines, and the like.
  • the chemical charge modifiers may be cationic polymer systems composed of a primary polymer material and a secondary polymer material.
  • the cationic polymer system may be composed of a primary polymer material such as polyamine epichlorohydrin and a secondary polymer material such as tetraethylene pentamine.
  • Exemplary chemically charge-modified filters composed of: 1) a filter sheet having a plurality of individual exposed cellulose fibers and silica based filter materials selected from silica particuiates and siliceous fibers; and 2) cationic chemical charge modifiers coated on or bonded to surfaces of the filter sheet are described in U.S. Patent No. 5,085,784, issued Feb. 4, 1992, to Ostreicher, and U.S. Patent No. 4,981,591, issued Jan. 1, 1991, to Ostreicher.
  • Such chemically charge-modified filters may be obtained from CUNO, Process Filtration Products, A Unit of Commercial Intertech Corporation, Meriden, Connecticut, under the trade designation Zeta Plus® VIROSORB® 1MDS.
  • the present invention relates to the discovery of the unexpected affinity of these materials for certain waterborne pathogens greater than 0.1 microns (i.e., 0.1 micrometers) in size and that these charge-modified filters may be utilized in a method to remove an unexpectedly substantial portion of such waterborne pathogens from aqueous liquid.
  • the present invention also relates to the discovery that these charge-modified filters may be utilized in a method to remove an unexpectedly substantial portion of waterborne pathogens greater than 0.1 microns in size from aqueous liquid to produce potable water.
  • the waterborne pathogens are be greater than about 0.1 micron in size.
  • the waterborne pathogens may be selected from Vibrio cholerae. E. coli, S. tvphimurium, S. flexineri. C. ieiuni, P. aerupinosa. G. lamblia, C. parvum and S. aureus.
  • Vibrio cholerae E. coli, S. tvphimurium, S. flexineri. C. ieiuni, P. aerupinosa. G. lamblia, C. parvum and S. aureus.
  • the present invention has been found to be particularly effective at removing Vibrio cholerae from aqueous liquid.
  • the reduction of Vibrio cholerae by practicing the described method is desirably greater than a log 3 reduction.
  • the reduction of Vibrio cholerae is desirably greater than a log 5 reduction.
  • Acceptable reductions of Vibrio cholerae may be achieved under a variety of conditions.
  • satisfactory reductions of Vibrio cholerae may be achieved when the waterborne pathogen contaminated aqueous liquid has a pH ranging from about 5 to about 9.
  • the present invention encompasses a method of removing waterborne pathogens from aqueous liquid utilizing a multi-layer filter material including at least two layers of the chemically charge-modified filter described above. Multiple layers of the filter material may be used to provide greater total surface area and/or other effects which may increase filtration efficiency.
  • the present invention also encompasses a method utilizing a multi-layer material including at least one layer of the chemically charge-modified filter described above and at least one other layer.
  • the other layer may be selected from woven fabrics, knit fabrics, bonded carded webs, continuous spunbond filament webs, meltblown fiber webs, films, apertured films, and combinations thereof. It is contemplated that the other layer may be selected to function in a variety of ways.
  • meltblown fiber web may be used to provide removal of gross contaminants from aqueous liquid.
  • Textile or spunbond fabrics may be selected to provide reinforcing or strength to the filter.
  • Other materials may be selected to provide bulk or strength to enhance handling of the filter or to facilitate assembly or construction of filter laminates, cartridges or the like.
  • the present invention also encompasses a method of removing waterborne pathogens from aqueous liquid utilizing the chemically charge-modified filter described above in a three- dimensional form or shape such as, for example, a tube, cylinder, cone, cube, sphere or the like.
  • a three- dimensional form or shape such as, for example, a tube, cylinder, cone, cube, sphere or the like.
  • the particular shape or configuration of the filter for an application may be determined by conventional methods.
  • An important aspect of the present invention described above further encompasses a method of removing a substantial portion of waterborne pathogens greater than 0.1 micron in size from water contaminated with such waterborne pathogens to produce potable water.
  • the method includes the step of passing the contaminated water through the chemically charge-modified filter described above so that a substantial portion of the waterborne pathogens greater than 0.1 micron in size is adsorbed onto the chemically charge-modified filter.
  • FIG. 1 illustrates the comparable uniformity of particle adsorption for an exemplary charge-modified glass/cellulose filter medium (Zeta Plus® VIROSORB® 1MDS, CUNO, Meriden, CT).
  • FIG. 1 is a 1000X linear magnification photomicrograph of a filter sheet with adsorbed polystyrene particles (300-nm in diameter).
  • An aqueous solution containing polystyrene particles at a concentration of 1.7 x 10 9 particles/mL was passed through the filter sheet mounted in a hand-held syringe disk filter apparatus (MILLIPORE 25mm diameter - available from Millipore Corporation, Bedford, Massachusetts).
  • a 5 mL aliquot of particle solution was passed through the filter sheet in approximately 30 seconds, followed by air to remove any excess liquid.
  • the filter sheet was then rinsed with a 5-20 mL volume of deionized water to remove any loosely-bound particles, which was then followed again by air to remove any excess liquid.
  • the method of the present invention utilizes certain chemically charge-modified filters to remove substantial portions of waterborne pathogens greater than about 0.1 micron in size from aqueous liquid contaminated with such waterborne pathogens.
  • the expression "removing a substantial portion of waterborne pathogens greater than about 0.1 micron in size from water contaminated with such waterborne pathogens” generally refers to removal of at least about 90 percent of the waterborne pathogens. In many instances, the removal rate will be significantly greater. For example, in some cases removal rates of 99 percent (a log 2 reduction) have been achieved. Removal rates of 99.9 percent (log 3 reduction), 99.99 percent (log 4 reduction), 99.999 percent (log 5 reduction) or greater have been achieved.
  • the filters of the present invention remove waterborne pathogens primarily by interactions between the surface charge on the filter material and the pathogens rather than by physical entrapment. Evidence that this is the case may be found in a comparison of the effective equivalent pore size of various filter material.
  • Pore sizes were determined by liquid displacement techniques utilizing a Coulter Porometer and Coulter POROFIL ⁇ test liquid available from Coulter Electronics Limited, Luton, England.
  • the mean flow pore size is determined by wetting a test sample with a liquid having a very low surface tension (i.e., Coulter POROFIL ⁇ ). Air pressure is applied to one side of the sample. Eventually, as the air pressure is increased, the capillary attraction of the fluid in the largest pores is overcome, forcing the liquid out and allowing air to pass through the sample. With further increases in the air pressure, progressively smaller and smaller holes will clear.
  • a flow versus pressure relationship for the wet sample can be established and compared to the results for the dry sample.
  • the mean flow pore size is measured at the point where the curve representing 50% of the dry sample flow versus pressure intersects the curve representing wet sample flow versus pressure.
  • the diameter of the pore which opens at that particular pressure i.e., the mean flow pore size
  • t surface tension of the fluid expressed in units of mN/M; the pressure is the applied pressure expressed in millibars (mbar); and the very low surface tension of the liquid used to wet the sample allows one to assume that the contact angle of the liquid on the sample is about zero.
  • the mean flow pore diameter was measured for a Millipore 0.5 micron filter available from Millipore Corporation, Bedford, Massachusetts; a Zeta Plus® Virosorb® 1MDS media disc available from CUNO, Meriden, Connecticut; and a 0.5 osy (-17 gsm) polypropylene meltblown nonwoven fabric available from Kimberly-Clark Corporation, Roswell, Georgia.
  • the results of pore size testing are reported in Table 1.
  • the MILLIPORE filter and the Virosorb® filter have mean flow pore sizes of about 35 times and about 5.9 times smaller, respectively, than 0.5 osy (-17 gsm) polypropylene meltblown nonwoven.
  • pore sizes measured for the Virosorb® filter and the polypropylene meltblown are greater than the diameters of at many types of waterborne pathogens including, for example, Vibrio Cholerae. Vibrio Cholerae and Bacterial Filtration
  • Samples of Zeta Plus® Virosorb® 1MDS media disc were tested for their ability to filter or remove Vibrio cholerae from aqueous solution.
  • the Vibrio cholerae were plated and an isolated colony was inoculated in 5 mL of sterile tryptic soy buffer which was incubated at 35 5 degrees Centigrade for 3 hours.
  • the Vibrio cholerae solution was measured at 420 nm and diluted until the absorbance was 0.64 for an approximate titer of 1x10 8 waterborne pathogens per mL.
  • One mL of the Vibrio cholerae solution was added to one liter of sterile water for an approximate initial titer of 1x10 s organisms per mL.
  • Zeta Plus® Virosorb® 1MDS media discs having a diameter of 48 mm were placed in a 0 filter vacuum apparatus. Two layers of filters were used to provide a total basis weight of approximately 35-40 grams per square meter. Approximately 40 mL of the cholera solution was filtered through the filters. The filtrate was serially diluted by adding 1 mL of filtrate to 9 mL of phosphate buffer solution (NaCI, Na 2 HPO , KH 2 PO 4 and distilled H 2 O). Approximately 0.1 mL of each dilution (0, -1, -2, -3, -4) was plated on 1% tryptic soy agar plates. The plates s were incubated for 24 hours.
  • phosphate buffer solution NaCI, Na 2 HPO , KH 2 PO 4 and distilled H 2 O
  • the filters provided greater than a 6.0 log reduction in the concentration of Vibrio 5 cholerae.
  • the data show that pH appeared to have little impact on Vibrio cholerae removal. Significant reductions in the concentration of other bacteria were also observed.
  • Samples of Zeta Plus® Virosorb® 1 MDS filter discs were tested for their ability to filter 0 or remove polio virus type 1 or MS2 bacteriophage (typically used as a surrogate for polio virus) from aqueous solution.
  • Two types of virus solution were used.
  • One solution was a buffer solution containing 0.02 M imidazole and 0.02 M glycine (pH 7.0). The other was dechlorinated tap water.
  • Solution containing MS2 had a concentration of approximately 1x10 6 MS2/mL.
  • Solution 5 containing polio virus had a concentration of approximately 1x10 5 polio/mL .
  • Two layers of 25 mm diameter Zeta Plus® Virosorb® 1 MDS filter discs were placed in stainless steel filter housings. Approximately 40 mL of the polio solution or the MS2 solution was forced through the filter utilizing a syringe at a flow rate of approximately 1 to about 3 mL/ sec. Approximately 0.3 mL of the filtrate was placed in a test-tube with 3 mL glycine/imidazole buffer (pH 7). Further 1:10 dilutions were done to produce a practical plate count.
  • MS2 plate count measurements were obtained by mixing 0.1 mL of the MS2 solution with 0.3 mL E. coli and plating in plate count agar containing crystal violet. Plaques formed by the virus in the bacteria lawn were counted. Polio plate counts measurements were obtained by plating on Green Monkey Kidney cell cultures and observing plaque formation. Results of testing are reported in Tables 3 and 4. The data reported under the headings "Unfiltered” and "Filter Effluent" are expressed in units of microorganisms per mL.
  • Simian rotavirus was added to buffer solution containing 0.02 M imidazole and 0.02 M glycine (pH 7.0). Approximately 50 mL of the seeded solution was passed at a rate of about
  • Buffer pH 7 (4 layers) 1.3x10" ⁇ 5 x 10" >99.6 > -2.41

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Abstract

L'invention concerne un procédé d'élimination d'une partie substantielle d'agents pathogènes aquatiques d'un liquide contaminé par ces agents pathogènes aquatiques. Le procédé comprend les étapes consistant à faire passer le liquide aqueux contaminé dans un filtre modifié chimiquement par une charge constituée: 1) d'une feuille filtrante présentant une pluralité de fibres de cellulose individuelles à nu et de matières filtrantes à base de silice choisies parmi des particules de silice et des fibres siliceuses; et 2) de modificateurs de charge chimique cationique enduits sur les surfaces de la feuille filtrante. Lorsque l'on passe le liquide aqueux contaminé dans le filtre modifié chimiquement par une charge, une partie substantielle des agents pathogènes aquatiques dont la taille est supérieure à environ 0,1 micron, est adsorbée sur le filtre modifié chimiquement par une charge. Le filtre est efficace pour éliminer les Vibrio cholerae.
PCT/US1997/010722 1996-07-29 1997-06-19 Procede d'utilisation d'un filtre modifie par une charge cationique WO1998004335A1 (fr)

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AU34059/97A AU3405997A (en) 1996-07-29 1997-06-19 Method of using cationic charge modified filter

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US68163896A 1996-07-29 1996-07-29
US08/681,638 1996-07-29

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WO1998004335A1 true WO1998004335A1 (fr) 1998-02-05

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AU (1) AU3405997A (fr)
ID (1) ID17560A (fr)
TW (1) TW369513B (fr)
WO (1) WO1998004335A1 (fr)
ZA (1) ZA975944B (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001007090A1 (fr) * 1999-07-21 2001-02-01 The Procter & Gamble Company Dispositif de filtration de microorganismes et procede d'elimination des microorganismes de l'eau
US6818130B1 (en) * 1999-09-30 2004-11-16 Kimberly-Clark Worldwide, Inc. Method and apparatus for multistage liquid filtration
EP1578693A2 (fr) * 2002-12-03 2005-09-28 Koslow Technologies Corporation Dispositif de miniaturisation de filtres de diffusion pour eliminer des particules
US20130244225A1 (en) * 2010-12-06 2013-09-19 Manjiri T. Kshirsagar Microorganism concentration process and device
US20130260370A1 (en) * 2010-12-06 2013-10-03 Manjiri T. Kshirsagar Microorganism concentration process and device
WO2015138556A1 (fr) * 2014-03-11 2015-09-17 3M Innovative Properties Company Filtre et procédé de production de celui-ci et système de filtration
WO2017074485A1 (fr) * 2015-10-30 2017-05-04 Z Probiotics Inc. Dba Z Bioscience Inc. Compositions probiotiques et leurs utilisations

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US6537614B1 (en) 1998-12-18 2003-03-25 Kimberly-Clark Worldwide, Inc. Cationically charged coating on hydrophobic polymer fibers with poly (vinyl alcohol) assist

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EP0360612A1 (fr) * 1988-09-23 1990-03-28 Hampshire Advisory And Technical Services Limited Système de purification d'eau
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001007090A1 (fr) * 1999-07-21 2001-02-01 The Procter & Gamble Company Dispositif de filtration de microorganismes et procede d'elimination des microorganismes de l'eau
US6565749B1 (en) 1999-07-21 2003-05-20 The Procter & Gamble Company Microorganism filter and method for removing microorganism from water
US6818130B1 (en) * 1999-09-30 2004-11-16 Kimberly-Clark Worldwide, Inc. Method and apparatus for multistage liquid filtration
EP1578693A2 (fr) * 2002-12-03 2005-09-28 Koslow Technologies Corporation Dispositif de miniaturisation de filtres de diffusion pour eliminer des particules
EP1578693A4 (fr) * 2002-12-03 2006-07-26 Koslow Techn Corp Dispositif de miniaturisation de filtres de diffusion pour eliminer des particules
US20130244225A1 (en) * 2010-12-06 2013-09-19 Manjiri T. Kshirsagar Microorganism concentration process and device
US20130260370A1 (en) * 2010-12-06 2013-10-03 Manjiri T. Kshirsagar Microorganism concentration process and device
WO2015138556A1 (fr) * 2014-03-11 2015-09-17 3M Innovative Properties Company Filtre et procédé de production de celui-ci et système de filtration
WO2017074485A1 (fr) * 2015-10-30 2017-05-04 Z Probiotics Inc. Dba Z Bioscience Inc. Compositions probiotiques et leurs utilisations

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AR007998A1 (es) 1999-11-24
TW369513B (en) 1999-09-11
AU3405997A (en) 1998-02-20
ZA975944B (en) 1998-02-02
ID17560A (id) 1998-01-08

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