The present invention is a method for controlling (e.g. inhibiting) the growth of microorganisms or killing microorganisms in an aqueous solution, such as that found in a water treatment facility or papermaking facility. The method includes adding an effective amount of (a) a free halogen-generating biocide, (b) a halogen stabilizer, and (c) a quaternary ammonium compound, a biocidal amine or salt thereof, or mixture thereof to the aqueous solution. The aqueous solution may be water in a recreational facility, an industrial cooling system, a water treatment facility or a water slurry, such as a circulating water slurry, in a papermaking facility. The mixture of the present invention is useful as a slimicide. The quaternary ammonium biocide and/or biocidal amine increase the efficacy of the free halogen-generating biocidal system.
In accordance with the present invention, there is provided a water treatment system for sterilizing water retained in a water container, the system comprising: a circulation process line for pumping the to-be-sterilized water out of the water container, sterilizing the water through electrolysis, and feeding the sterilized water back into the water container; means for producing a sterilizing solution having a sterilizing function by electrolyzing an electrolytic solution containing chlorine ions and having a function of promoting an electrochemical reaction; and means for supplying the produced sterilizing solution into the circulation process line as required. The system can constantly sterilize the water in the circulation process line and, as required, additionally supply the sterilizing solution produced by the sterilizing solution producing means into the circulation process line according to a variation in the quality of the water. Thus, the quality of the water in the water container can properly be maintained.
The apparatus and methods of the present invention enable efficient and appropriate treatment of Urban Water Runoff, so that the treated Urban water Runoff can be can be introduced into public waterways without contaminating such waterways. The system apparatus utilizes adsorptive Organoclay media, mechanical filtration and ultraviolet sterilization. The methods and apparatus of the present invention remove contaminants from Urban Water Runoff to a level which enable the resulting effluent to meet appropriate standards for introducing the treated Urban water Runoff in to public waterways. The method and apparatus of water treatment of the present invention does not utilize chlorine containing compounds which, when combined with organic compounds can produce THM's that can become problematic when re-introduced to the downstream environment. The systems of the present invention can be made sufficiently compact so as to enable their use in remote locations.