Treatment of circulating water systems

摘要

The present invention relates to a method of inhibiting the growth of killing algae, bacteria, yeast and/or fungi in a recirculating water system which comprises adding to the water a polymeric biguanide and an adjuvant of the Formula (1) or a salt thereof; wherein: R<1 >is an optionally substituted C8 to C12 or C18 to C22 alkyl group; and R<2 >and R<3 >each independently is H or optionally substituted C1-4-alkyl.