Patent ID: RE39021

Claim:
A method of enhancing the efficacy of a free halogen-generating slimicide and reducing organic halogen by-products in an organic matter-containing circulating water system which comprises adding an N-hydrogen compound selected from the group consisting of p-toluene-sulfonamide, dimethylhydantoin, methylethylhydantoin, cyanuric acid, succinimide, urea, 4,4-dimethyl-2-oxazolidinone, and glycouril, directly to said system before or after the addition of the slimicide or with said slimicide in a mixture consisting essentially of the slimicide and said compound; wherein the N-hydrogen compound is added at a ratio sufficient to maintain a 0.1:1 to 10:1 mole ratio of slimicide to N-hydrogen compound in the circulating system, wherein at least 0.2 weight percent of said organic matter is present in said system, wherein the slimicide is chlorine gas, bromine, bromine chloride, an alkali metal or alkaline earth metal hypohalite, a halogenated hydantoin, a halogenated cyanurate, or halogenated cyanuric acid, and wherein said mixture of the N-hydrogen compound and the slimicide is present in said system in a slimicidally effective amount.