Patent ID: 7449120

Claim:
A process for killing microorganisms and controlling biofouling in high chlorine demand water, which comprises mixing a solution of sodium hypochlorite and a solution of at least one ammonium salt, in a molar ratio calculated as N/Cl of at least 1:1, to form a biocidal mixture, the concentration of said mixture being 0.01% to 2.0% as Cl 2 and adding said mixture to said water immediately following said mixing, said ammonium salt being selected from the group consisting of halides, sulfates and nitrates, said mixture having a pH of 8.0 to 12.6, said mixture being characterized in having at least one of: a higher killing of aerobic and anaerobic microorganisms than sodium hypochlorite alone or a mixture of sodium hypochlorite and sodium bromide in high chlorine demand water; a higher efficacy than sodium hypochlorite alone or dibromonitrilopropionamide in controlling bacterial growth in domestic waste containing a high concentration of amines; and a higher efficacy than sodium hypochlorite alone or a mixture of sodium hypochlorite and sodium bromide against fecal coli in domestic waste.