氯消毒剂对冷却塔军团菌的现场杀灭效果评价

Chlorination of Cooling Tower and the Control of Legionella

目的研究含氯消毒剂对冷却塔军团菌的现场杀菌效果。方法选择一大型冷却塔,分别进行两种消毒方式:一次添加高浓度氯消毒剂后(冲击法),维持加氯和不维持加氯,并在当天和一周后检测冷却塔水中军团菌的浓度。结果持续加氯,保持游离余氯在(0.38±0.23)mg/L,军团菌浓度变化不大,未检出或保持低浓度(0.85±1.52～0.81±1.56)cfu/ml;不持续加氯,军团菌持续上升,一周后增加100～1000倍以上(0.12±0.11～322.22±130.17)cfu/ml。结论维持加氯的消毒方法对冷却塔军团菌的消毒效果较好。

Objective To evaluate the bactericidal effect of chlorine in killing Legfonella in water cooling towers. Methods A large cooling tower was selected in this study. Two different protocols of disinfection were evaluated： （1） by keep on adding the disinfectant chlorine and （2） by adding chlorine once a week. The number of Legionella in the cooling water was determined daily. Results In the first protocol, when the concentration of available chlorine was kept at （0.38±0.23）mg/L,the number of Legionella did not change obviously （0.85±1.52- 0.81±1.56）cfu/ml. In the second protocol,when chlorine was added once a week, the number of Legionella was increasing. The concentration of LegioneUa was found to increase 100-1 000 times（0.12±0.11-322.22±130.17） cfu/ ml at 1 week after the experiment. Conclusion Maintaining the concentration of chlorine in water cooling tower is essential in controlling the growth Legionella.