Abstract: Disclosed are compositions for stabilizing a source of active halogen in aqueous solution. The compositions comprise (i) at least one substituted N-hydrogen compound, such as 5,5-dimethylhydantoin, and (ii) at least one additional nitrogen compound selected from ammonia, ammonium salts, and nitrogen compounds containing no carbon-hydrogen bonds, the molar ratio of (i) and (ii) being in the range of 50:1 to 0.02:1. Active halogen-containing aqueous solutions stabilized by the above compositions are particularly useful for controlling microbial and planktonic growth in aqueous systems such as process liquids in the pulping or papermaking industry. The compositions are also useful in reducing the corrosivity of halogen-containing solutions.

Abstract: Disclosed are compositions for stabilizing a source of active halogen in aqueous solution. The compositions comprise (i) at least one substituted N-hydrogen compound, such as 5,5-dimethylhydantoin, and (ii) at least one additional nitrogen compound selected from ammonia, ammonium salts, and nitrogen compounds containing no carbon-hydrogen bonds, the molar ratio of (i) and (ii) being in the range of 50:1 to 0.02:1. Active halogen-containing aqueous solutions stabilized by the above compositions are particularly useful for controlling microbial and planktonic growth in aqueous systems such as process liquids in the pulping or papermaking industry. The compositions are also useful in reducing the corrosivity of halogen-containing solutions.

Abstract: The inventors have discovered that partially halogenated hydantoins exhibit superior antimicrobial efficacy and decreased performance additive decomposition rates than fully halogenated hydantoins, such as dichlorodimethyl hydantoin (DCDMH). Partially halogenated hydantoins are solutions containing monochlorohydantoin and, optionally, dihalogenated hydantoin or non-halogenated hydantoin. The present invention is a method of reducing slime in a circulating water slurry comprising organic matter and one or more performance additives, such as optical brighteners, while minimizing decomposition of the performance additives. The method comprises adding one or more partially halogenated hydantoins, such as Cl1.1-chlorodimethyl hydantoin, to the slurry. The concentration of partially halogenated hydantoin maintained in the slurry generally ranges from about 0.01 to about 50 ppm (expressed as Cl2). This method is particularly useful for circulating water slurries in paper processing.

Abstract: The inventors have discovered that partially halogenated hydantoins exhibit superior antimicrobial efficacy and decreased performance additive decomposition rates than fully halogenated hydantoins, such as dichlorodimethyl hydantoin (DCDMH). Partially halogenated hydantoins are solutions containing monochlorohydantoin and, optionally, dihalogenated hydantoin or non-halogenated hydantoin. The present invention is a method of reducing slime in a circulating water slurry comprising organic matter and one or more performance additives, such as optical brighteners, while minimizing decomposition of the performance additives. The method comprises adding one or more partially halogenated hydantoins, such as Cl1 1-chlorodimethyl hydantoin, to the slurry. The concentration of partially halogenated hydantoin maintained in the slurry generally ranges from about 0.01 to about 50 ppm (expressed as Cl2). This method is particularly useful for circulating water slurries in paper processing.