PROBLEM TO BE SOLVED: To provide a method for treating an open circulation cooling water system capable of securely sterilizing and suppressing Legionella on a nondetection level, and to which chemical resistant bacteria and Algae having chemical resistance are hard to be propagated.SOLUTION: Provided is a method for treating an open circulation cooling water system, in which cooling water of an open circulation cooling water system is subjected to treatment with a halogen oxide at all times and is also subjected to treatment with an organic bactericide for one or more times on 30 days.COPYRIGHT: (C)2014,JPO&INPIT【課題】レジオネラ属を確実に不検出レベルに殺菌、抑制することができ、しかも薬剤耐性菌や薬剤耐性を持った藻類が繁殖しにくい開放循環冷却水系の処理方法を提供する。【解決手段】開放循環冷却水系の冷却水に対して、ハロゲン系酸化物による処理を常時行い、かつ、有機系殺菌剤による処理を30日間に1回以上行う開放循環冷却水系の処理方法。【選択図】なし
