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WO1996001231A1 - Traitement de l'eau - Google Patents

Traitement de l'eau Download PDF

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Publication number
WO1996001231A1
WO1996001231A1 PCT/GB1995/001540 GB9501540W WO9601231A1 WO 1996001231 A1 WO1996001231 A1 WO 1996001231A1 GB 9501540 W GB9501540 W GB 9501540W WO 9601231 A1 WO9601231 A1 WO 9601231A1
Authority
WO
WIPO (PCT)
Prior art keywords
water
silver
ligand
organic ligand
silver ions
Prior art date
Application number
PCT/GB1995/001540
Other languages
English (en)
Inventor
Stuart William Carr
Ronald Joseph Lambert
Original Assignee
Unilever N.V.
Unilever Plc
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 Unilever N.V., Unilever Plc filed Critical Unilever N.V.
Priority to BR9508174A priority Critical patent/BR9508174A/pt
Priority to AU28015/95A priority patent/AU2801595A/en
Priority to EP95923461A priority patent/EP0768987A1/fr
Publication of WO1996001231A1 publication Critical patent/WO1996001231A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
    • C02F1/505—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment by oligodynamic treatment
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
    • A01N59/16—Heavy metals; Compounds thereof
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/4606—Treatment of water, waste water, or sewage by electrochemical methods for producing oligodynamic substances to disinfect the water

Definitions

  • This invention relates to the hygienic treatment of water.
  • a known technique for doing this is to liberate silver ions into the water, by an electrochemical reaction.
  • Silver ions are known to have an antimicrobial action. This use of electrochemically generated silver ions has been discussed in a number of literature articles including
  • the silver is normally liberated into a solution at a concentration which does not exceed 0.1 parts per million (ppm) . It may be noted that standards for potable water in UK and USA impose limits of 0.08 and 0.05 ppm respectively. At such concentrations, silver is rather slow in its cell killing action.
  • the present invention provides a method of killing microbial contaminants in water by introducing silver ions into solution in the water characterised by including in the water an organic ligand which is able to form a soluble co-ordination complex with the silver ions, especially an amphoteric or zwitterionic surfactant, a polyether, or a polycarboxylate.
  • the invention is particularly applicable when the silver ions are liberated into solution by the known step of electrochemical reaction, although the silver could conceivably be introduced into the water in some other way, such as by adding a solution of a silver salt.
  • the electrolytic liberation of silver ions requires apparatus which provides an electrolytic cell, with a silver-containing anode in contact with water to be treated. This water may be in contact also with the cathode, or the cathode may be located in different electrolyte separated by a permeable membrane from the water to be treated.
  • the anode may be silver, or a silver alloy from which both silver ions and other ions are liberated.
  • Stainless steel which is an alloy principally containing iron, chromium and nickel
  • Silver itself may usefully be used as the cathode, and the direction of the current may be reversed periodically, so that both electrodes are consumed.
  • the water to be treated needs some conductivity. The concentration of ions which occur in normal water supplies is usually sufficient for this. If required, a small quantity of an electrolyte may be added to the water.
  • ligands able to form water soluble complexes with silver.
  • Such ligands should have a functional group capable of taking a negative charge for co-ordinating to silver. These groups will generally contain such heteroatoms as oxygen, sulphur and phosphorus. Examples of functional groups which bind to silver are thioethers, ethers, thiocarbonates, amines, imines, pyrazoles, benzimidazoles and phosphines.
  • the ligands do not need to carry an overall negative charge. For instance zwitterionic molecules can serve as ligands.
  • polycarboxylates especially polycarboxylates wherein each ligand molecule contains at least three carboxylate groups able to co ⁇ ordinate to silver.
  • Particularly suitable are oligomers and polymers bearing carboxylate groups such that a ligand molecule bears at least three carboxylate groups capable of co-ordinating to silver.
  • Such ligands display a high affinity for silver and can enhance the stability of the silver ions against precipitation by hydroxyl or chloride ions. Surprisingly, however, the coordination complexes of silver with such ligands also display good antimicrobial/biocidal activity - which would not be expected when the silver is strongly bound by the ligand.
  • such ligands contain an average of more than one carboxylate group per monomer residue in the oligomer or polymer.
  • Such ligands may contain monomer residues which each contribute a plurality of carboxylate groups. Examples of such monomers are maleate, fumarate, itaconate, and aconitate.
  • the oligomers and polymers contain a majority of monomer residues bearing carboxylate groups, especially a majority of monomer residues which, as discussed, each contain a plurality of carboxylate groups.
  • a polycarboxylate will, usually, be made from olefinically unsaturated monomers. It may be a random or block copolymer. One or more monomers which bear a plurality of carboxylate groups, such as maleate, may be copolymerised with monomers which bear a single carboxylate group, such as acrylate or methacrylate. Other possible comonomers do not have ionisable carboxylate groups, as for example vinyl acetate.
  • a preferred category of monomers which may provide 20. mole% or more, especially 50 mole% or more, of a polymer or oligomer, have the formula
  • each of R and R_ which may be the same or different, represents a hydrogen atom, a methyl group or an ethyl group
  • each of M and M which may be the same or different, is a hydrogen atom or a solubilising cation.
  • Such monomers may be used to provide 20 to 95 mole % of a polymer or oligomer in which the residues of comonomer have the formula
  • R- represents a hydrogen atom or an acyl group -COR. in which R is a C. to C alkyl group.
  • Polymeric ligands can be prepared by conventional polymerisation techniques. For example a procedure for the polymerisation of maleic anhydride is given by Lang et al in J. Polymer Sci . issue 162, page 532 (1961) . The resulting polymer can readily be hydrolysed to polymaleate by treatment with aqueous sodium hydroxide.
  • olefinically unsaturated acids and diacids can be polymerised alone or jointly with other olefinic monomers such as vinyl acetate by conventional techniques for radical polymerisation.
  • Polyitaconate homopolymers are described in US 3055 873 and 3405060. Copolymers with acrylic acid are disclosed in EP 506 246. Other polycarboxylates are described in EP 193 360 and US 4725655.
  • Polycarboxylates can also be obtained from monomers which do not contain olefinic unsaturation but instead undergo condensation polymerisation. Examples are malonate, isocitrate, citrate, succinate, tartrate, oxaloacetate, methylmalonate, carballylate, aspartate, glutamate and gamma-carboxyglutamate.
  • amphoteric surfactants containing amino groups and carboxylate groups. Preferred among these are amphoteric surfactants containing at least two secondary amino groups as well as a carboxylate group. Amphoteric surfactants will also generally incorporate an alkyl or alkenyl chain of 7 to 18 carbon atoms.
  • R. is a C Threat to C 8 straight or branched alkyl or alkenyl group; R.. and R, are each C to C_ alk_ or C to C- hydroxyalkyl. n is 2 to 4 especially 3.
  • a further category of materials useful as organic ligands are a group of naturally occurring antibiotics known as polyether ionophores. These molecules incorporate a number of oxygen atoms, frequently in furan and pyran rings so that they are polyethers. They are known to have cation complexing properties. A review and listing of such materials is provided in "Polyester antibiotics" edited by J.W. Westley.
  • water treatment in accordance with this invention is carried out using the organic ligand and silver ions in such quantities that complexing of the silver is not restricted by shortage of ligand.
  • some surplus of ligand will usually be harmless, while the benefit of the invention will be obtained in part if there is some surplus of silver ions in solution. Consequently it is preferred that substantially all the silver is in the form of a complex, and is accompanied by surplus ligand.
  • the mole ratio of silver to ligand will be from 10:1 up to 1:100.
  • the concentration of organic ligand will lie in a range from 0.001 or 0.005 to 3,000 ppm, especially 0.5 or lppm up to 500 ppm. Concentrations of ligand higher than 3,000 ppm may be employed if desired.
  • the concentration of silver which is maintained in the water will frequently lie in a broad range from 0.001 to 1000 ppm, especially 0.01 or 0.1 to 100 ppm.
  • the concentration more preferably does not exceed 25 ppm.
  • the invention is applied to the treatment of a body of water which is kept for a long time - notably a body of water which is kept in circulation, such as the water of a swimming pool or an air conditioning system, a single addition of ligand to the water may suffice for a long period.
  • Example 1 On the other hand if the water is being consumed and replaced, the organic ligand will have to be added to it regularly or continuously, and the introduction of silver ions, preferably by electrolytic liberation, will need to be regular or continuous.
  • Example 1 On the other hand if the water is being consumed and replaced, the organic ligand will have to be added to it regularly or continuously, and the introduction of silver ions, preferably by electrolytic liberation, will need to be regular or continuous.
  • Example 1 Example 1 .
  • Silver ions were generated electrolytically in water, and in aqueous solutions of an organic ligand.
  • a control has water with neither silver nor organic ligand present.
  • the ligand was a commercial mixture of amphoteric surfactants of formulae C 12 H 25 -NH- (CH 2 ) 3 -NHCH 2 C0 2 H and C 12 H 25 -NH- (CH 2 ) -NH- (CH 2 ) -NHCH 2 C0 2 H available as Amphobac 4 from Lonza Inc. It was used at concentrations of 2ppm and 20ppm.
  • Silver was generated electrolytically, using a pair of silver wires dipping into the water or ligand solution as electrodes. These were connected to a constant current direct current supply, for sufficient time to liberate 3 ppm silver ions into solution.
  • the quantities of surviving micro organisms were determined by serial dilution, spreading the diluted solution on an agar plate, incubating and counting the number of colonies of each species. From this count, and the extent of dilution, the concentration of surviving micro organisms in the test solution was calculated. The results are set out in the following table and are given as the logarithm of the number of survivors .
  • Example 1 The procedure of Example 1 was repeated, using Lasalocid as organic ligand, at a concentration of 15ppm.
  • Lasalocid is a polyether antibiotic of formula
  • Example 1 The procedure of Example 1 was repeated using a longer contact time, using E.coli and Staph aureus as the microorganism species, and using an amidopropyl betaine as ligand. This had the formula
  • the silver concentration was 2 ppm.
  • a copolymer was prepared from 20 mole % vinyl acetate and
  • This polymer had the formula
  • R_ indicates an acetyl group
  • indices n and m indicate the numbers of repeating units.
  • Example 3 The procedure of Example 3 was repeated using the copolymer as the ligand, at a concentration of 16 ppm, again providing an excess of ligand over silver. The results obtained were log 10 surviving cells after 1 hour
  • copolymer enhanced the activity against E.coli without significant deteriment to the activity against St. aureus .
  • Example 5 lOOg of the polyitaconate-vinyl acetate copolymer in sodium salt form, as in the previous Example, was dissolved in 500ml water. Silver nitrate (30g) dissolved in 80ml water was added over about 5 minutes. The whole mixture was stirred for twenty minutes and then ethanol (1.5 litre) was added. A fine white precipitate formed, which was filtered off and dried.
  • Candida parapsilopsis yeast
  • Penicillium and Aspergillus spores milasaccharide
  • Escherichia coli Gram negative bacterium
  • Staphylococcus aureus Gram positive bacterium

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  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Organic Chemistry (AREA)
  • Water Supply & Treatment (AREA)
  • Hydrology & Water Resources (AREA)
  • Agronomy & Crop Science (AREA)
  • Health & Medical Sciences (AREA)
  • Electrochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Pest Control & Pesticides (AREA)
  • Plant Pathology (AREA)
  • General Chemical & Material Sciences (AREA)
  • Dentistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • Environmental Sciences (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)

Abstract

On traite de l'eau avec des ions argent en tant qu'agent antimicrobien accompagné d'un agent complexant, de façon à augmenter l'efficacité et/ou la stabilité des ions argent. L'agent complexant est un ligand organique qui forme un complexe solide avec les ions argent. Les matériaux préférés sont des matériaux polymères incorporant au moins trois groupes carboxylate capables de constituer un coordonné avec l'argent. Egalement préférés sont des tensioactifs amphotères/zwitterioniques et des polyethers.
PCT/GB1995/001540 1994-07-01 1995-06-29 Traitement de l'eau WO1996001231A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BR9508174A BR9508174A (pt) 1994-07-01 1995-06-29 Processo para exterminar contaminantes microbianos em água
AU28015/95A AU2801595A (en) 1994-07-01 1995-06-29 Water treatment
EP95923461A EP0768987A1 (fr) 1994-07-01 1995-06-29 Traitement de l'eau

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9413299A GB9413299D0 (en) 1994-07-01 1994-07-01 Water treatment
GB9413299.0 1994-07-01

Publications (1)

Publication Number Publication Date
WO1996001231A1 true WO1996001231A1 (fr) 1996-01-18

Family

ID=10757683

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1995/001540 WO1996001231A1 (fr) 1994-07-01 1995-06-29 Traitement de l'eau

Country Status (8)

Country Link
EP (1) EP0768987A1 (fr)
AU (1) AU2801595A (fr)
BR (1) BR9508174A (fr)
CA (1) CA2191580A1 (fr)
GB (1) GB9413299D0 (fr)
TR (1) TR199500775A2 (fr)
WO (1) WO1996001231A1 (fr)
ZA (1) ZA955353B (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998016109A1 (fr) * 1996-10-15 1998-04-23 Gyre Ltd. Systeme chimique generant des especes d'oxygene reactives en continu et leurs procedes d'utilisation
WO1999061567A1 (fr) * 1998-05-29 1999-12-02 Unilever N.V. Compositions lubrifiantes
WO2000062618A1 (fr) * 1999-04-20 2000-10-26 Kareem Batarseh Formulations microbicides et procedes pour le controle des microorganismes
US6630172B2 (en) 2001-01-22 2003-10-07 Kareem I. Batarseh Microbicidal composition containing potassium sodium tartrate
US6759544B2 (en) 2001-06-22 2004-07-06 Nutrinova Nutrition Specialties & Food Ingredients Gmbh Antimicrobially active acesulfame complexes, process for their preparation and their use
GB2402880A (en) * 2003-06-20 2004-12-22 Johnson & Johnson Medical Ltd Antimicrobial silver complexes
WO2006125125A3 (fr) * 2005-05-19 2007-12-06 Ethicon Inc Compositions polymeres antimicrobiennes et leur utilisation
WO2011088205A1 (fr) * 2010-01-15 2011-07-21 Ethicon, Inc. Compositions polymères antimicrobiennes et utilisation de celles-ci
US10808047B2 (en) 2015-08-21 2020-10-20 G&P Holding, Inc. Silver and copper itaconates and poly itaconates

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB748283A (en) * 1952-06-21 1956-04-25 Ions Exchange And Chemical Cor Improvements in or relating to organic metal compounds and processes for making such compounds
JPS59222405A (ja) * 1983-05-31 1984-12-14 Hirobumi Arino 銀錯体を使用する抗微生物剤
GB2197861A (en) * 1984-05-04 1988-06-02 Tripolymer Int Pty Ltd Algicidal composition
US4915955A (en) * 1986-04-22 1990-04-10 Sanosil Ag. Process for preparing a disinfectant
EP0494373A1 (fr) * 1991-01-10 1992-07-15 Brendan James Delaney Composition pour le traitement de bassins de natation
US5366636A (en) * 1994-03-18 1994-11-22 Kansas State University Research Foundation Method of treating water with resin bound ionic silver

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB748283A (en) * 1952-06-21 1956-04-25 Ions Exchange And Chemical Cor Improvements in or relating to organic metal compounds and processes for making such compounds
JPS59222405A (ja) * 1983-05-31 1984-12-14 Hirobumi Arino 銀錯体を使用する抗微生物剤
GB2197861A (en) * 1984-05-04 1988-06-02 Tripolymer Int Pty Ltd Algicidal composition
US4915955A (en) * 1986-04-22 1990-04-10 Sanosil Ag. Process for preparing a disinfectant
EP0494373A1 (fr) * 1991-01-10 1992-07-15 Brendan James Delaney Composition pour le traitement de bassins de natation
US5366636A (en) * 1994-03-18 1994-11-22 Kansas State University Research Foundation Method of treating water with resin bound ionic silver

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Dialog Information Services, File 347, Japio database, Accession number 01510805, Arino Hirobumi:"Antimicrobial agent using silver complex", & JP 59-222405 *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998016109A1 (fr) * 1996-10-15 1998-04-23 Gyre Ltd. Systeme chimique generant des especes d'oxygene reactives en continu et leurs procedes d'utilisation
WO1999061567A1 (fr) * 1998-05-29 1999-12-02 Unilever N.V. Compositions lubrifiantes
WO2000062618A1 (fr) * 1999-04-20 2000-10-26 Kareem Batarseh Formulations microbicides et procedes pour le controle des microorganismes
US6242009B1 (en) 1999-04-20 2001-06-05 Kareem I. Batarseh Microbicidal formulations and methods to control microorganisms
US6939566B2 (en) 1999-04-20 2005-09-06 Kareem I. Batarseh Microbicidal formulations and methods to control microorganisms
US6630172B2 (en) 2001-01-22 2003-10-07 Kareem I. Batarseh Microbicidal composition containing potassium sodium tartrate
US6759544B2 (en) 2001-06-22 2004-07-06 Nutrinova Nutrition Specialties & Food Ingredients Gmbh Antimicrobially active acesulfame complexes, process for their preparation and their use
GB2402880B (en) * 2003-06-20 2008-01-23 Johnson & Johnson Medical Ltd Antimicrobial compositions comprising silver
GB2402880A (en) * 2003-06-20 2004-12-22 Johnson & Johnson Medical Ltd Antimicrobial silver complexes
WO2006125125A3 (fr) * 2005-05-19 2007-12-06 Ethicon Inc Compositions polymeres antimicrobiennes et leur utilisation
EP2401913A3 (fr) * 2005-05-19 2012-11-21 Ethicon, Inc. Compositions polymères antimicrobiennes et leur utilisation
US9149558B2 (en) 2005-05-19 2015-10-06 Ethicon, Inc. Antimicrobial polymer compositions and the use thereof
US9149559B2 (en) 2005-05-19 2015-10-06 Ethicon, Inc. Antimicrobial polymer compositions and the use thereof
US9180229B2 (en) 2005-05-19 2015-11-10 Ethicon, Inc. Antimicrobial polymer compositions and the use thereof
WO2011088205A1 (fr) * 2010-01-15 2011-07-21 Ethicon, Inc. Compositions polymères antimicrobiennes et utilisation de celles-ci
CN102711852A (zh) * 2010-01-15 2012-10-03 伊西康公司 抗微生物的聚合物组合物及其用途
CN102711852B (zh) * 2010-01-15 2016-03-30 伊西康公司 抗微生物的聚合物组合物及其用途
US10808047B2 (en) 2015-08-21 2020-10-20 G&P Holding, Inc. Silver and copper itaconates and poly itaconates

Also Published As

Publication number Publication date
BR9508174A (pt) 1997-11-11
AU2801595A (en) 1996-01-25
TR199500775A2 (tr) 1996-06-21
EP0768987A1 (fr) 1997-04-23
CA2191580A1 (fr) 1996-01-18
GB9413299D0 (en) 1994-08-24
ZA955353B (en) 1996-12-30

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