| abstract |
A biocidal composition for the treatment of water comprises a cationic polyquaternary ammonium biocide, e.g. an ionene halide, or a quaternary ammonium biocide or a quaternary ammonium biocide comprising a long chain alkyl group and three other groups selected from lower alkyl and aralkyl groups, together with a source of transition metal cations e.g. copper II cations and/or a biocide of the type containing a gem. bromonitromethylene group e.g. 2- bromo-2-nitropropane-1,3-diol. |