Albemarle Corporation

Michael J Sanders

Christopher J Nalepa

Jonathan N Howarth

David L Shelton

Robert L Davis

David N Roark

Pranab Choudhury

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.

Microbiological control in aqueous systems

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.

Microbiological control in aqueous media and/or eradication or reduction of biofilm on a surface in contact with such media is achieved by introducing into the aqueous medium a microbiocidally effective quantity of one or more 1,3-dibromo-5,5-dialkylhydantoins where one of the alkyls is methyl and the other is a Calkyl, wherein (i) the molar quantity of 1,3-dibromo-5,5-dialkylhydantoin introduced is less than the molar quantity of N,N'-bromochloro-5,5-dimethylhydantoin that would be required to effect the same degree of microbiological control in that medium, (ii) the molar quantity of the 1,3-dibromo-5,5-dialkylhydantoin introduced releases an amount of 'free chlorine' that is greater than the amount of 'free chlorine' that would be released in that medium by an equimolar quantity of N,N&#x2032;-bromochloro-5,5-dimethylhydantoin, and (iii) the amount of &#x201c;free chlorine&#x201d; released by the quantity of the 1,3-dibromo-5,5-dialkylhydantoin introduced is greater than the amount of &#x201c;free chlorine&#x201d; that could be predicted to be released by that quantity of 1,3-dibromo-5,5-dialkylhydantoin on the basis of the amount of &#x201c;free chlorine&#x201d; that would be released in that medium by an equimolar quantity of N,N&#x2032;-bromochloro-5,5-dimethylhydantoin.

Methods for microbiological control in aqueous systems

Reduced stabilization time of oxidation-reduction potential is achieved in a recreational body of water by baseloading bromide ions and dialkylhydantoin prior to biocidal treatment of the water body with N,N&prime;-dihalo-5,5-dialkylhydantoin.

Methods and systems for uniform-control of bromine concentrations in water

Microbiological control in aqueous media and/or eradication or reduction of biofilm on a surface in contact with such media is achieved by introducing into the aqueous medium a microbiocidally effective quantity of one or more 1,3-dibromo-5,5-dialkylhydantoins where one of the alkyls is methyl and the other is a C alkyl, wherein (i) the molar quantity of 1,3-dibromo-5,5-dialkylhydantoin introduced is less than the molar quantity of N,N&prime;-bromochloro-5,5-dimethylhydantoin that would be required to effect the same degree of microbiological control in that medium, (ii) the molar quantity of the 1,3-dibromo-5,5-dialkylhydantoin introduced releases an amount of &ldquo;free chlorine&rdquo; that is greater than the amount of &ldquo;free chlorine&rdquo; that would be released in that medium by an equimolar quantity of N,N&prime;-bromochloro-5,5-dimethylhydantoin, and (iii) the amount of &ldquo;free chlorine&rdquo; released by the quantity of the 1,3-dibromo-5,5-dialkylhydantoin introduced is greater than the amount of &ldquo;free chlorine&rdquo; that could be predicted to be released by that quantity of 1,3-dibromo-5,5-dialkylhydantoin on the basis of the amount of &ldquo;free chlorine&rdquo; that would be released in that medium by an equimolar quantity of N,N&prime;-bromochloro-5,5-dimethylhydantoin.

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&prime;-bromochloro-5,5-dimethyl hydantoin. Still other advantages are made possible by the described technology.

Microbiological control in water systems is achieved with an amount,of 1,3-dibromo-5,5-dimethylhydantoin that is less than the amount of N,N&prime;-bromochloro-5,5-dimethylhydantoin required to achieve the same degree of microbiological control. The methods of combating and/or in an aqueous medium, and biofilms such as formed by on surfaces contacted by the aqueous medium, involve introducing into the medium a biocidally effective amount of 1,3-dibromo-5,5-dimethylhydantoin. A microbiological control agent for use in water in accordance with U.S. Environmental Protection Agency regulations is purveyed in containers of a water control agent comprising 1,3-dibromo-5,5-dimethylhydantoin, which containers bear a label having thereon dosage levels pursuant to requirements promulgated by the U.S. Environmental Protection Agency. The 1,3-dibromo-5,5-dimethylhydantoin is used or purveyed either as a product having a large average particle size (e.g., 175 microns or more) or in the form of a compacted product. The compacted product can be formed without using a binder where the average particle size of the 1,3-dibromo-5,5-dimethylhydantoin is about 175 microns or more. Alternatively, the compacted product can be formed using a micronized synthetic polyolefin-based hydrocarbon wax and/or a micronized synthetic polyfluorocarbon wax as a binder, provided the wax is compatible with the 1,3-dibromo-5,5-dimethylhydantoin. In this case, the average particle size can be in the range of about 20-600 microns. Similarly, the compacted product can be a product formed from 1,3-dibromo-5,5-dimethylhydantoin having an average particle size of at least 175 microns, using an amount of a saturated, normally solid, fatty amide as the binder.

A water soluble dialkylhydantoin and a source of bromide ion are added to a body of water needing sanitization. This is followed by contacting the body of water with an oxidizing agent, which creates biocidal species in situ in the body of water.

Solid mixtures of dialkylhydantoins and bromide ion sources for water sanitization

This invention describes a method for stabilizing bromine biocides in water. A water-soluble bromide salt and a sulfamate source are added to a body of water, and then an oxidant is added to the body of water to form the biocidal bromine species.

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Baton Rouge, LA, United States of America

Michael J Sanders