Calgon Corporation

Ann M Sherbondy

Daniel P Vanderpool

Bennett P Boffardi

Polyether polyamino methylene phosphonates, which possess high calcium tolerance and have been found to give excellent inhibition of the formation, deposition and adherence of scale-forming salts, especially calcium carbonate, in aqueous systems involving severe conditions which include elevated pH, high dissolved solids content, and high saturation levels of calcium carbonate, are degraded by the oxidizing biocides bromine and chlorine used to control microbial growth in such aqueous systems. It has been found that organic sulfonamides provide excellent protection against such degradation when they are added to the aqueous system along with the polyether polyamino methylene phosphonate scale inhibitors.

Stabilization of polyether polyamino methylene phosphonate scale

Aminomethylene phosphonates, which give excellent inhibition of the formation, deposition and adherence of scale-forming salts, especially calcium carbonate, in aqueous systems, are degraded by the oxidizing biocides bromine and chlorine used to control microbial growth in such aqueous systems. It has been found that organic sulfonamides provide excellent protection against such degradation when they are added to the aqueous system along with the aminomethylene phosphonate scale inhibitors.

Stabilization of aminomethylene phosphonate scale inhibitors against

Hydroxyalkylidene phosphonates, which give excellent inhibition of the formation, deposition and adherence of scale-forming salts, especially calcium carbonate, in aqueous systems, are degraded by the oxidizing biocides bromine and chlorine used to control microbial growth in such aqueous systems. It has been found that organic sulfonamides provide excellent protection against such degradation when they are added to the aqueous system along with the hydroxyalkylidene phosphonate scale inhibitors.

Stabilization of hydroxyalkylidene phosphonate scale inhibitors against

Monofluorophosphate salts, especially sodium monofluorophosphate (Na.sub.2 PO.sub.3 F), when added to various industrial water systems in concentrations between 0.1 mg/L and 50 mg/L, significantly reduce the amount of calcium carbonate scale which is formed on heat exchange and other metallic surfaces of such systems. Monofluorophosphate salts, especially sodium monofluorophosphate, when added to various water systems in concentrations between 0.1 mg/L and 50 mg/L also stabilizes soluble manganese ion and its reaction products, i.e., primarily MnO.sub.2, in desirable forms and reduced particle sizes. Monofluorophosphate salts, especially sodium monofluorophosphate, when added to various water systems in concentrations between 1 mg/L and 500 mg/L also stabilizes soluble iron ion and its reaction products, i.e., primarily Fe.sub.2 O.sub.3.

Monofluorophosphate for calcium carbonate scale control and iron and

Monofluorophosphate salts, especially sodium monofluorophosphate (Na.sub.2 PO.sub.3 F), when added to potable water sources in concentrations between 0.1 mg/L and 500 mg/L, significantly reduces lead (Pb) leaching into said water, producing the double benefit of reducing lead solubility and thus content in drinking water, while at the same time adding fluoride to that drinking water, with the anticaries benefit that fluoridation provides.

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Pittsburgh, PA, United States of America

Ann M Sherbondy