Abstract: A method and composition for removing barium and strontium sulfate scale deposits. The composition comprises an aqueous solution having a pH of about 8 to about 14, an EDTA or DTPA chelant, and a catalyst or synergist. Preferred chelants comprise diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA) or alkali salts thereof. Anions of organic and inorganic acids comprise the catalyst. Catalysts which can be used include Fluoride, oxalate, persulfate, dithionate, hypochlorite and formate anions also thio, amino, and hydroxy acetate anions. When the solution containing the composition is contacted with a surface containing a scale deposit, the deposit dissolves substantially more scale quicker than heretofore possible.

Abstract: A method of preventing and inhibiting scale on solid surfaces in contact with mineral processing waters which comprises treating such waters with a scale preventing or inhibiting amount of a composition comprising:______________________________________ Ingredients % By Weight ______________________________________ A. Polyacrylic acid 25-65 B. An acrylic acid lower alkyl acrylate ester 25-65 copolymer which contains from 1-6 carbon atoms in the alkyl group C. An acrylamide terpolymer which contains 0-30 from 1-80 mole % of acrylic acid and from 1-50 mole % of an alkyl sulfonate substituted acrylamide wherein the alkyl group contains from 1-6 carbon atoms ______________________________________with polymers A, B, and C having a molecular weight range between 1,000 to 50,000.

Abstract: A method for the inhibition of silica deposition on the internal surfaces of an aqueous system comprising adding to the aqueous system a phosphonate compound and a water soluble polymer having the structure: ##STR1## wherein M is a water soluble cation. The aqueous systems in which the water soluble phosphonate and polymer are particularly effective on cooling water and boiler systems.

Abstract: A method for controlling the formation of silica/silicate deposits in aqueous systems by adding an effective amount, preferably at least 0.1 ppm, of 2-phosphonobutane tricarboxylic acid-1,2,4 and, optionally, an anionic polymer, preferably a carboxylic/sulfonic polymer, or salts thereof to the aqueous system being treated. Borate or molybdate ion sources may also be added.

Abstract: Compounds having the formula I: ##STR1## wherein M.sub.1, M.sub.2, M.sub.3 , independently, are hydrogen, C.sub.1 -C.sub.4 alkkyl, phenyl, a monovalent or an equivalent of a polyvalent metal atom, ammonium or a substituted ammonium ion; R.sub.1 is C.sub.1 -C.sub.4 alkyl substituted by one or more hydroxy or carboxyl groups; and p is an integer.The new compounds are useful in the treatment of aqueous systems, in particular to inhibit scale deposition from aqueous systems.

Abstract: A corrosion inhibitor for aqueous systems containing ferrous and non-ferrous metallic surfaces comprising (a) hydroxyphosphonoacetic acid, or a water soluble salt thereof, and (b) an aminoalkylenephosphonic acid derivative, or a water soluble salt thereof.

Abstract: This invention is directed to the treatment of aqueous systems and specifically to the inhibition and removal of scale and solid deposits in industrial water systems. The invention comprises the use of substoichiometric amounts of an inhibitor composition comprising at least one acrylic polymer, at least one water-soluble polymer derived from maleic acid or its anhydride, a water-soluble organic phosphonate and at least one water-soluble chelating agent. This inhibitor composition is added to the water in the systems in amounts ranging from about 0.01 to 600 parts of the inhibitor per million parts by weight of the water.

Abstract: Composition for treating cooling water including a combination of ingredients for combatting a variety of problems, such as corrosion, scale control and microbiological growth. Composition obviates the necessity for separately feeding several materials. Compositon includes at least 1% sodium molybdate, at least 0.1% benzotriazole, at least 0.5% citric acid and at least 5% of a microbiocide.

Abstract: Addition of a secondary scale inhibitor is made to a water medium containing a primary phosphonate scale inhibitor to inhibit precipitation of insoluble calcium phosphonates which are formed by the reaction of calcium in the water medium with the primary scale inhibitor thus forming insoluble calcium phosphonate. The secondary scale inhibitor has the function of inhibiting precipitation of such insoluble calcium phosphonates. The secondary scale inhibitor is a copolymer of an acrylic acid and/or methacrylic acid with one or more of a principal comonomer selected from substituted acrylamides, alkoxyalkyl acrylates, substituted and unsubstituted alkyl acrylates, acrylamido alkane sulfonic acids, hydroxyalkyl acrylates, alkyl itaconates, and mixtures thereof.

Abstract: Calcium carbonate scale is controlled by treating calcium carbonate containing waters with a predominantly phosphinate containing composition where has as its major ingredient more than 32 mole percent of a phosphinicosuccinic acid oligomer having the probable structural formula . ##STR1## M is H, Na, K, NH.sub.4, or mixtures thereof; and m and n are either 0 or a small whole number with proviso that either m or n is a small whole number and the sum of m plus n is greater than 2.

Abstract: A squeeze treatment for preventing scale utilizes as the scale inhibitor a predominantly phosphinate containing composition comprising:______________________________________ Mole Percent - Ingredients Less Than ______________________________________ A. Monosodium phosphinicobis - 22 (succinic acid) B. Monosodium phosphinico- 26 succinic acid C. Sodium phosphonosuccinic acid 12 D. Sodium phosphate 5 E. Sodium phosphite 6 F. Sodium hypophosphite, and 6 G. A phosphinicosuccinic acid oligomer having the probable structural formula: ##STR1## ______________________________________wherein G exceeds 25 mole percent, M is H, Na, K, NH.sub.4, amine salts and mixtures thereof and m and n are either 0 or a small whole number with the proviso that either m or n is a small whole number and the sum of m plus n is greater than 2.

Abstract: A solid calcium hypochlorite composition contains hydrated calcium hypochlorite and an alkali metal salt of phosphonobutane polycarboxylic acid having an available chlorine concentration of at least 50 percent by weight and a water content of at least 4 percent by weight.It has been found that the use of the novel compositions of the present invention can significantly reduce scale formation in dispensers for calcium hypochlorite particularly where water having high total alkalinity is used. The prevention or inhibition of scale formation is accomplished without harmfully affecting other properties of the pool water such as the pH.

Abstract: A method of treating and removing volatile organic contaminants from ground water by treating the water with effective amounts of a water-soluble polymeric sequesterant comprising polymers derived from acrylic acid or organic acid, followed by the addition of a biocide, e.g., chlorine, and then subsequently passing the treated water through a packed column or air stripper wherein the volatile organic contaminants are removed by passing air in a counter-direction to the flow of water at temperatures ranging from about 40.degree. to about 200.degree. F.

Abstract: This invention is directed to the treatment of aqueous systems, and specifically to the inhibition and removal of scale and solid deposits in industrial water systems. The invention comprises the use of less than a stoichiometric amount of an inhibitor composition comprising at least one acrylic polymer, at least one water-soluble polymer derived from maleic acid or its anhydride, water-soluble organic phosphonates, and at least one water-soluble chelating agent. This inhibitor composition is added to the water in the systems in amounts ranging from about 0.01 to 600 parts of the inhibitor composition per million parts by weight of the water.

Abstract: A method is shown of treating an aqueous system comprising adding to the system a water-soluble tri-copolymer having the formula I:(A).sub.x (B).sub.y (C).sub.z Ior a salt thereof, wherein A is a group having the formula: ##STR1## or a hydrolysed (dicarboxylic acid or salt) form of this group; B is a group having the formula:--CH.sub.2 --C(R.sub.1)(CO.sub.2 R.sub.2)--wherein R.sub.1 is a hydrogen or methyl, and R.sub.2 is hydrogen or C.sub.1 -C.sub.8 straight- or branched chain alkyl, preferably methyl or ether, or R.sub.2 is C.sub.1 -C.sub.8 straight- or branched chain alkyl substituted by a group --OR.sub.3 wherein R.sub.3 is hydrogen or a group of formula --[CH.sub.2 CH(R.sub.4)O].sub.n H wherein R.sub.4 is hydrogen or methyl and n is an integer from 1 to 10; C is a group having the formula:--CH(R.sub.5)--C(R.sub.6)(R.sub.7)--wherein R.sub.5 is hydrogen, phenyl or C.sub.1 -C.sub.18 straight- or branched chain alkyl, preferably hydrogen and R.sub.6 and R.sub.7, independently, are hydrogen, C.sub.1 -C.sub.

Abstract: A process for the treatment of cooling waters, particularly in thermal power stations, without or--optionally--with partial acid decarbonization of the make up water, the improvement wherein the make up water is mechanically coarse-clarified and the hardness is then stabilized with scale inhibitors. The scale inhibitors are then removed from the blow down and are optionally recovered.

Abstract: Methods for utilizing transition metals as tracers in aqueous liquid systems are provided by this invention. Transition metals with low background levels in system waters are identified as preferred when soluble in said aqueous liquid systems. The transition metals show low levels of deposition on equipment scale and provide reliable information as to the process history of the liquid systems.

Abstract: The instant invention is directed to an admixture, and its use in inhibiting scale and corrosion in aqueous systems, comprising:(a) a water-soluble polymer having a weight average molecular weight of less than 25,000, as determined by low angle laser light scattering, comprising an unsaturated carboxylic acid and an unsaturated sulfonic acid, or their salts, having a ratio of 1:20 to 20:1, and(b) at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphonates, phosphates, polyphosphates, metal salts and sulfonates.The instant invention is also directed to a method of inhibiting the formation of insoluble alluvial, metal oxide and metal hydroxide deposits in an aqueous system, comprising adding to the system at least 0.

Abstract: A method of inhibiting the corrosion of the metal surfaces of beer pasteurizing units in contact with halogenated water vapor which comprise treating these halogenated waters with at least 1/4 ppm sulfamic acid for each ppm of halogen present in these waters.

Abstract: A method for inhibiting scale deposition and the corrosion of metal surfaces in a cooling water system.It comprises a water soluble copolymer consisting of moities of acrylic acid and monohydroxylated alkyl allyl ether, a phosphonate compound, a water soluble zinc salt and, optionally, an azole compound, and/or a water soluble molybdate salt.

Abstract: This invention relates to a process of dissolving and removing silicate scale and particularly magnesium silicate scale and sludge from various aqueous systems, particularly boiler water and desalination systems by adding to the water effective amounts of at least one water-soluble phosphinocarboxylic acid. These polyphosphinocarboxylic acids and the salts thereof are added to the water in the aqueous system in amounts ranging up to about 50 thousand parts by weight per million and preferably in amounts ranging up to about 2000 parts by weight per million parts by weight of water either alone or in combination with at least one organic dispersant selected from the group consisting of nonionic and anionic dispersants.

Abstract: A method of inhibiting manganese deposition in open, recirculating aqueous systems is disclosed. A water soluble acrylic acid/allyl hydroxy propyl sulfonate ether copolymer having repeat units characterized by the structural formula: ##STR1## wherein M is a water soluble cation, the molar ratio x:y is from about 3:1 to about 6:1 and the number average molecular weight of the copolymer is from about 5,000 to about 10,000, preferrably with an organic phosphonate is added to the aqueous system. The organic phosphonate is preferably hydroxy ethylidene diphosphonic acid, diethylene triamine penta-(methylene phosphonic acid) or blends thereof. The copolymer or copolymer and phosphonic acid is effective in inhibiting the deposition of manganese in aqueous systems.

Abstract: Oxa-alkane polyphosphonic acids corresponding to general formula (I) ##STR1## in which R.sup.1 is a C.sub.1 -C.sub.10 alkyl group, an optionally substituted C.sub.6 -C.sub.10 aryl group, a phenyl- or naphthylalkyl group, a group having the general formula ##STR2## or a group having the general formula ##STR3## R.sup.2 represents H or methyl, A represents the structural unit ##STR4## where n is an integer of from 1 to 20 and M represents H or the cation of a base, to the use of the above compounds as complexing agents and as thresholders, and to compositions containing one or more compounds of general formula (I).

Abstract: Process for the recovery of a transition metal from an aqueous solution containing a complex of the transition metal with a cyclic phosphite by hydrolyzing the cyclic phosphite, contacting the hydrolysis reaction mixture with a compound forming a water-stable complex with the transition metal, extracting the reaction mixture thus formed with an organic extraction agent for the water-stable complex and separating an organic extract phase containing the transition metal from an aqueous raffinate phase. The process is particularly suitable for the recovery of the Rh or Co from spent hydroformylation catalysts and of Pd from spent carbonylation catalysts.

Abstract: 3-R.sup.1 -3-oxoprop-1-ene-1,1-diphosphonic acids corresponding to the following general formula ##STR1## in which R.sup.1 is a tertiary substituted alkyl group, an optionally substituted cycloalkyl group, or an optionally substituted aryl or heteroaryl group, andM is hydrogen or the cation of a base;to a process for their production in which 3-R.sup.1 -3-oxo-1-aminopropane-1,1-diphosphonic acids corresponding to the following general formula ##STR2## in which R.sup.1 is as defined above, are reacted with an aqueous or alcoholic alkali metal hydroxide solution; then water followed by an alcohol infinitely miscible with water is added to the reaction mixture, and the pure olefinic diphosphonic acids are obtained by addition of an acid; to the use of the above compounds of formula III as complexing agents and as thresholders; and to compositions containing one or more compounds of formula (III).

Abstract: A scale inhibiting composition comprises the combination of (a) a copolymer of an alkene, preferably a branched chain alkene, and an unsaturated dicarboxylic acid or anhydride, in acidic or neutralized form, and (b) an organic polyphosphonic acid or salt.A preferred composition contains the sodium salt of a copolymer of isobutene and maleic anhydride and 1-hydroxyethyl-1,1-diphosphonic acid.The compositions may be used in secondary or tertiary oil recovery, desalination of sea water and the softening of boiler feed water.

Abstract: This invention is directed to a method for controlling the formation of silica/silicate deposits in aqueous systems by adding an effective amount, preferably at least 0.1 ppm, of an imine polymer, a phosphonate and, optionally, a source of molybdate or borate ions to the aqueous system being treated.

Abstract: A process for treating water which comprises adding to the water (a) from 1 to 50 ppm of a phosphonium compound of the formula: ##STR1## in which R represents C.sub.1 -C.sub.6 groups which are unsubstituted or substituted by a cyano, hydroxy, esterified hydroxy or aryl group, R.sub.1 represents a C.sub.8 -C.sub.18 alkyl group and X represents chlorine or bromine, and optionally (b) from 0.1 to 100 ppm of an anionic water treatment agent such as a scale or corrosion inhibiting agent.

Abstract: Methods of controlling the formation of calcium oxalate in aqueous systems are disclosed. The methods comprise adding from about 0.1 to 500 ppm of a water soluble (meth)acrylic acid/allyl ether copolymer to the desired water system. The methods are especially well adapted for use in pulping and paper making systems wherein calcium oxalate is often encountered as a troublesome scale forming compound.

Abstract: A water soluble polymer composition is disclosed. The polymer has repeat units characterized by the structural formulae: ##STR1## wherein R.sub.1 is H or lower alkyl (C.sub.1 -C.sub.3); R.sub.2 is OH, OM, or NH.sub.2 ; M is a water soluble cation; R.sub.3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to 6 carbon atoms; X is an anionic radical; Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1. The copolymer is effective in inhibiting the precipitation of certain scale forming salts, and also acts to inhibit corrosion of metal parts in contact with water systems.

Abstract: A method of inhibiting corrosion in cooling tower systems comprising adding to a cooling tower water containing sulfides, hydrocarbons or mixtures thereof as contaminants a corrosion inhibiting composition containing a water-soluble zinc compound, a water-soluble molybdate, a water-soluble orthophosphate and a water-soluble polyphosphate.

Abstract: New composition of polymers and methods of use are disclosed. The polymers are water soluble and are composed of repeat units formed from an .alpha.,.beta. ethylenically unsaturated compound, and repeat units formed from allyl alkylene phosphonates.

Abstract: Aqueous or partly aqueous systems are treated against the corrosion of metals, especially ferrous metals, in contact therewith, and/or against scale deposition therefrom, by adding to these systems from 0.1 to 50 000 ppm of 2-hydroxyphosphonoacetic acid having the formula I ##STR1## or a water-soluble salt thereof.

Abstract: A method of preventing corrosion and scale formation on metals exposed to industrial recirculating waters having a pH ranging between about 7.0 to about 9.5, which consists essentially of adding to said industrial recirculating waters an effective amount of a combination of a water-soluble zinc salt, a nitrogen-containing N-alkylated acrylamide zinc complexing polymer and an orthophosphate ion source, wherein:(a) the weight ratio of zinc to nitrogen-containing zinc complexing polymer ranges between 1:1 to about 1:20;(b) the nitrogen-containing N-alkylated acrylamide zinc complexing polymer has a weight average molecular weight ranging between 2,000 to 25,000 and is selected form the group consisting of water-soluble copolymers and terpolymers containing at least two mole percent of an N-alkylated acrylamide monomer, wherein the nitrogen substituted alkyl group contains from 3-12 carbon atoms and wherein the N-alkyl group may be linear or branched.

Abstract: This invention pertains to the use of certain phosphorus compounds in conjunction with other materials which characterize cleaners of alkaline earth metal salts, metal oxide/hydroxide salts, and silica/silicate salts, particularly citric acid, malic acid, oxalic acid, ammonium bifluoride and sodium bifluoride. Amount of the phosphorus compounds is 0.5 to 70%, preferably 2 to 40%, based on 100% of a cleaner composition which includes the phosphorus compounds. Suitable phosphorus compounds are selected from aminoalkyl and hydroxyalkyl phosphonic acids and phosphonates, phosphonoalkanepolycarboxylic acids and salts thereof, polyphosphoric acids and salts thereof, and polyol phosphate esters.

Abstract: A corrosion inhibitor for ferrous and non-ferrous aqueous systems comprising (a) a water soluble phosphonic acid or salt thereof, preferably an amino methylene phosphonic acid; (b) a phosphonocarboxylic acid, preferably a phosphonoalkane carboxylic acid; (c) an azole, preferably benzotriazole or tolyltriazole; and (d) a water soluble molybdate salt, preferably sodium molybdate.

Abstract: A method of dissolving mineral salts comprising contacting the mineral salts with a solution of water, an additive consisting essentially of six moles of 1-hydroxyethane, 1, 1-diphosphonic acid mixed with one mole of hydroxymethylene phosphonic acid, phosphonoformic acid, sulfamic acid, oxalic acid, hydroxyacetic acid, 2-amino ethane sulfonic acid, or fluoroboric acid and neutralized to a pH of 7.0, and a polymeric dispersant.

Abstract: A water soluble polymer composition is disclosed. The polymer has repeat units characterized by the structural formula: ##STR1## wherein R.sub.1 is H or lower alkyl (C.sub.1 -C.sub.3); R.sub.2 is OH, OM, or NH.sub.2 ; M is a water soluble cation; R.sub.3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to 6 carbon atoms; X is an anionic radical; Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1. The copolymer is effective in inhibiting the precipitation of certain scale forming salts, and also acts to inhibit corrosion of metal parts in contact with water systems.

Abstract: Corrosion inhibiting compositions for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems contain sequestrants such as carboxylic acids, phosphates, or optionally sulfur containing lignosulfonates, as well as carboxylated phosphonic acids of the formula ##STR1## wherein m is from 1 to about 6, wherein n is from 0 to about 6, wherein R is --H, -alkyl, -alkenyl, -alkynyl, -aryl, -alkyl substituted aryl, -cycloalkyl, -methylene phosphonic acid, or -methylene carboxylic acid, and wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently is --H, -alkyl, -aryl, -alkyl substituted aryl, --OH, --SH, --NH.sub.2, --PO.sub.3 H.sub.2, --CH.sub.2 PO.sub.3 H.sub.2, --CO.sub.2 H, --CH.sub.2 CO.sub.2 H, halogen, or --SO.sub.3 H. The composition can also contain other corrosion inhibiting compounds such as azoles, molybdates, and the like.

Abstract: Water-soluble zinc:polymer complexes of nitrogen-containing polymers are useful in preventing corrosion in aqueous recirculating systems operating within the pH range of 7.0-9.5, when combined with orthophosphate ion sources.

Abstract: An antiscalant admixture is disclosed of a homopolymer of maleic acid or a copolymer and a phosphonoalkane carboxylic acid for reducing scaling in an aqueous system wherein the weight ratio of said copolymer to said phosphonic acid is 5:1 to 1:5, wherein molecular weight of said copolymer is 2,000 to 20,000, and wherein said polymer is composed of at least two of the comonomers selected from monounsaturated monocarboxylic and dicarboxylic acids of 3 to 5 carbon atoms, water-soluble salts thereof, and alkyl esters thereof of 1 to 6 carbon atoms in said alkyl groups; substituted acrylamides; acrylamidoalkane sulfonic acids and water-soluble salts thereof; vinyl sulfonic acid and water-soluble salts thereof; hydroxyalkyl acrylates with 2 to 4 carbons in the alkylene group; styrene sulfonic acids and water-soluble salts thereof; allyloxyhydroxyalkane sulfonic acids and water-soluble salts; vinyl carboxylates; polymerized vinyl alcohols and water-soluble salts thereof; and mixtures of such comonomers.

Abstract: A method for stabilizing metal ions in recirculating water systems is disclosed. This method utilizes 2-hydroxyphosphonoacetic acid at a dosage of 0.1-100 ppm to solubilize metal ions thereby reducing deposition and corrosion.

Abstract: For water-treatment in swimming pools, cooling towers, hot tubs, and other systems, it is desired to feed various chemicals in small quantities but at optimum rates into the system. In several embodiments of the invention the water is recirculated through the system which usually includes a filter. It has been discovered that the chemicals can be fed by enclosing them in generally spherical plastic capsules suggestive of table tennis balls, but about the size of a base ball. The rate of feeding depends upon the size and number of small holes which are provided, or the user pokes through the shell of the capsule, upon the solubility of the chemical, and upon the flow rate of the water through a strainer, skimmer, or other chamber in the system into which the capsule is introduced. The random orientation of the capsule tends to average out variations.

Abstract: It has now been found that certain phosphonate derivatives of bis(aminoalkyl) piperazines are good threshold agents to prevent metal ion precipitation in aqueous solutions. They also function as sequestering and/or chelating agents as do those which do not contain the phosphonate group.

Abstract: A water soluble polymer composition is disclosed. The polymer has repeat units characterized by the structural formulae: ##STR1## wherein R.sub.1 is H or lower alkyl (C.sub.1 -C.sub.3); R.sub.2 is OH, OM or NH.sub.2 ; M is a water soluble cation; R.sub.3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 5 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to 6 carbon atoms; X is an anionic radical; Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1. The copolymer is effective in inhibiting the precipitation of certain scale forming salts, and also acts to inhibit corrosion of metal parts in contact with water systems.

Abstract: The decomposition of phosphonates by chlorine-bromine solutions present in industrial process waters can be diminished or prevented by treating such waters with sulfamic acid.

Abstract: A composition and method for inhibiting corrosion in industrial cooling waters which contain hardness and have a pH of at least 8, which composition comprises a water-soluble organic phosphonate capable of inhibiting corrosion in an aqueous alkaliine environment and a hydrocarbon polymer containing an N-substituted acrylamide polymer with an amide structure as follows: ##STR1## where R.sub.2 is hydrogen or methyl, R.sub.1 is a hydrogen or an alkyl and R is alkylene or phenylene, and X is sulfonate, (poly)hydroxyl, and combinations thereof.

Abstract: A method for inhibiting corrosion in industrial cooling waters which contain hardness and a pH of at least 6.5, comprising using a water-soluble inorganic phosphate capable of inhibiting corrosion in an aqueous alkaline environment and a co- or terpolymer of acrylic acid and certain substituted acrylamides such as t-butyl acrylamide. A water-soluble organic phosphonate capable of inhibiting corrosion in an alkaline environment may be used as an adjunct for the phosphate.

Abstract: An all-in-one treatment composition for a water cooling tower includes a water soluble aromatic azole corrosion inhibitor such as benzotriazole, an organophosphorous antiscalant and a polymeric quaternary ammonium compound. The polymeric quaternary ammonium compound has the following general formula: ##STR1## The composition is suitable for use at low level continuous applications rates. The polymeric quaternary ammonium compound is also suitable for use at low concentration as a continuous biocide/biostat. This compound does not suffer from the acclimatization typically encountered when one biocide is used on a continuous low level basis.

Abstract: A process and composition using hydroxyphosphonoacetic acid or its water-soluble salts in combination with certain copolymers, such as water-soluble 1-acrylamido-2-methylpropane sulfonic acid copolymers with acrylic acid or methacrylic acid, provide improved corrosion protection for iron based metal in contact with the system water of aqueous systems.