Methods for microbiological control in aqueous systems

Abstract

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′-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.