METHOD FOR TREATING COOLING WATER SYSTEM

摘要

A method for treating a cooling water system includes adding a (meth)acrylic acid-based copolymer to a cooling water system having a part where the calcium hardness of the cooling water is 150 to 300 mg/L and the flow rate of the cooling water is 0.3 to 0.5 m/s, wherein the (meth)acrylic acid-based copolymer has a structural unit (a) derived from a specific (meth)acrylic acid-based monomer (A) and a structural unit (b) derived from a specific (meth)allyl ether-based monomer (B), the content of the structural unit (b) is 15% by mole to 20% by mole relative to 100% by mole of the structural units derived from all the monomers, the weight-average molecular weight of the (meth)acrylic acid-based copolymer is 10,000 to 30,000, and at least one of the main chain terminal groups of the (meth)acrylic acid-based copolymer is a sulfonic acid group or a salt thereof.