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AssigneeAlbemarle Corporation
InventorsJonathan N. Howarth, Christopher J. Nalepa, Michael J. Sanders, David L. Shelton
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Microbiological control is achieved by continuously and inexpensively dosing water in contact with biofilm, or that comes into contact with biofilm, using a highly effective biocide that provides very effective microbiocidal control of planktonic microorganisms and of biofilm species, even where the biofilm infestations have been in existence for long periods of time and thus have encased themselves in a substantial quantity of slimy defensive polysaccharide layers or films. In addition, the biocide used makes possible significant reduction in copper and/or iron surfaces in contact with the water as compared to N,N′-bromochloro-5,5-dimethyl hydantoin. Still other advantages are made possible by the described technology.
A method of achieving an effective “free chlorine” level in treating with a biocide water that is in contact with, or that comes into contact with, at least one iron or copper surface, which method comprises introducing into said water a biocidally effective amount of at least one biocide consisting essentially of 1,3-dibromo-5,5-dialkylhydantoin wherein said amount (i) provides in the water a biocidally effective “free chlorine” level that is within 90% of the “total chlorine” level in the water thereby enabling the rate of said 1,3-dibromo-5,5-dialkylhydantoin biocide consumption to be reduced as compared to N,N′-bromochloro-5,5-dimethylhydantoin, and (ii) reduces the rate of corrosion of said iron or copper with which the water is or comes into contact as compared to N,N′-bromochloro-5,5-dimethylhydantoin, said at least one 1,3-dibromo-5,5-dialkylhydantoin that is introduced into said water being characterized in that one of the alkyl groups in the 5-position is a methyl group and the other alkyl group in the 5-position has in the range of 1 to 4 carbon atoms.
A method of achieving an effective “free chlorine” level in treating with a biocide water that is or that comes into contact with at least one iron or copper surface, which method comprises treating said water with a biocide consisting essentially of at least one 1,3-dibromo-5,5-dialkyihydantoin at a rate that (i) provides in the water a biocidally effective “free chlorine” level, (ii) reduces the rate of corrosion of said iron or copper with which the water is or comes into contact as compared to N,N′-bromochloro-5,5-dimethylhydantoin, and (iii) provides in the water a “free chlorine” level that is within 90% of the “total chlorine” level in the water thereby enabling the rate of biocide consumption in treating said water to be reduced as compared to N,N′-bromochloro-5,5-dimethylhydantoin, said at least one 1,3-dibromo-5,5-dialkylhydantoin that is introduced into said water being characterized in that one of the alkyl groups in the 5-position is a methyl group and the other alkyl group in the 5-position has in the range of 1 to 4 carbon atoms.
A method of effecting microbiocidal activity in a body of water that is in contact with, or that comes into contact with, at least one iron or copper surface, which method comprises providing in said body of water by use of a biocide consisting essentially of at least one 1,3-dibromo-5,5-dialkylbydantoin, a concentration of “free chlorine” that (A) is greater than could be predicted from the concentration of “free chlorine” provided by an equimolar amount of N,N′-bromochloro-5,5-dimethylhydantoin, and (B) results in less corrosion of said at least one iron or copper surface as compared to an equal concentration of free chlorine from N,N′-bromochloro-5,5-dimethylhydantoin, said at least one 1,3-dibromo-5,5-dialkylhydantoin that is used being characterized in that one of the alkyl groups in the 5-position is a methyl group and the other alkyl group in the 5-position has in the range of 1 to 4 carbon atoms.
Dependencies are inferred from the claim text.