水系におけるシリカ系スケールの防止方法及びスケール防止剤、並びにシリカ系スケールを抑制するとともに金属の腐食を抑制する水処理方法及び水処理剤

摘要

PROBLEM TO BE SOLVED: To provide a method for preventing silica scale and a scale inhibitor exhibiting enough scale preventing effects even in the coexistence of an aluminum ion, an iron ion, a zinc ion and the like in a water system such as a cooling water system, a boiler water system and a geothermal power generation water system, and to provide a water treatment method and water treatment agent for preventing silica scale as well as corrosion of metals.SOLUTION: A method for preventing silica scale in a water system includes adding one or more kind selected from polyethylene glycol having a molecular weight of 200 to 800, polyethylene glycol monomethyl ether into a water system containing a total concentration of 0.5 mg/L or more of metals selected from aluminium, iron and zinc.