US 5,662,940 A · Biocidal methods and compositions for recirculating water systems

Abstract

Improved biocidal composition and method for controlling biofouling and microorganism population levels in recirculating water systems such as cooling towers, swimming pools or spas is disclosed and claimed. The composition comprises a hypochlorite donor and a bromide ion donor in proportions selected to maintain a mole ratio of the sum of all bromine containing species to the sum of all hypohalite species in the recirculating water of about 0.2 to about 20. The method comprises introducing into the recirculating water a mixture or combination of a hypochlorite donor and a bromide ion donor in an amount sufficient to maintain a ratio of the sum of all bromine containing species to the sum of all species in the recirculating water in the range of about 0.2 to about 20. In addition, a bromine volatilization suppressant may be introduced into the recirculating water to inhibit loss of bromide ion through volatilization of bromine containing species formed by reaction of the hypochlorite donor and the bromide ion donor. One or more scale inhibitors and compacting aids may also be added.

Claims64

Dependent claims

A method of providing prolonged and controlled release of hypobromous acid in a recirculating water system comprising

(i) determining the rate of loss of bromide ion from the system due to blow-down, volatilization and formation of stable organobromine compounds;
and
(ii) adding to the system a solid biocidal composition comprising a hypochlorite donor and a bromide ion donor in amounts sufficient to make said composition perform as a bromine biocide in said recirculating water system;
(iii) wherein said hypochlorite donor is selected from the group consisting of trichloro-s-triazinetrione, dichloroisocyanuric acid, or mixtures thereof;
and
(iv) wherein said bromide ion donor is sodium bromide.

3 more elements

A method of controlling biofouling and microorganism population levels in a recirculating water system comprising (a) determining the rate of loss of bromide ion from the system due to blow-down, volatilization and formation of stable organobromine compounds;

and (b) adding, in a biocidally effective amount to provide prolonged and controlled release of hypobromous acid and to maintain the mole ratio of the sum of all bromine containing species to the sum of all hypohalite species in the recirculating water in the range of at least about 0.2 to about 20, a solid biocidal composition comprising a hypochlorite donor, a bromide ion donor in amounts sufficient to make said composition perform as a bromine biocide in said recirculating water system, and a bromine volatilization suppressant
wherein said hypochlorite donor is selected from the group consisting of trichloro-s-triazinetrione, dichloroisocyanuric acid, calcium hypochlorite;
sodium dichloro-s-triazinetrione;
potassium dichloro-s-triazinetrione;
or mixtures thereof;
and
wherein said bromide ion donor is potassium bromide;
and
wherein said bromine volatilization suppressant is selected from the group consisting of unsubstituted, halogenated or alkylated hydantoin;
unsubstituted, halogenated or alkylated sulfonamide;
unsubstituted, halogenated, or alkylated sulfamic acid;
unsubstituted, halogenated, or alkylated glycoluril;
unsubstituted, halogenated, or alkylated succinimide;
unsubstituted, halogenated or alkylated oxazolidinone;
or unsubstituted, halogenated or alkylated imidazolidinone.

12 more elements

Dependencies are inferred from the claim text.

Biocidal methods and compositions for recirculating water systems

Life of this patent

Biocidal methods and compositions for recirculating water systems

Life of this patent

Abstract

Claims64