含氯消毒液对活性污泥的影响及其应对措施

在新型冠状病毒感染的肺炎疫情期间,消毒液(次氯酸盐)的使用量大幅提升,导致排水中的消毒液含量增加。消毒液虽然在调节池和管网输送过程中会被还原,但依然存在污水厂进水次氯酸盐增加的风险,可能会对活性污泥系统造成一定程度的冲击。因此,如何判断污水处理厂是否受到冲击以及如何应对这种潜在风险成为广泛关注的问题。整理了课题组关于次氯酸钠对活性污泥微生物活性影响的相关研究成果,旨在为疫情期间污水处理厂的安全运营提供一些建议及应对措施。特别需要指出,当进水氯负荷超过4 mg/(gSS·d)或污泥恢复指数RI长期维持在较高水平时(如超过16%),表明系统受到了冲击,面临较大的事故风险,污水厂需采取措施消除进厂水中高浓度余氯对系统的影响。

Effect of Chlorine Disinfectant on Activated Sludge and Its Countermeasures

Currently,at the outbreak period of COVID-19,the consumption of chlorine disinfectant increased significantly,leading to the rapid increase of disinfectant content in wastewater.Although the disinfectant could be reduced in the septic tanks and pipe networks,the risk of increased hypochlorous acid to the treatment plants still exists.This might cause the hypochlorite shock on the activated sludge system to some extent.Therefore,it has been a matter of great concern to judge whether the wastewater treatment plant was shocked and to deal with this potential risk.The research results of the effect of sodium hypochlorite(NaClO)on the microbial activity of activated sludge were summarized,aiming to provide some suggestions and countermeasures for the safe operation of wastewater treatment plants(WWTPs)during the epidemic period.In particular,it needs to be noted that when the influent chlorine load exceeds 4 mg/(gSS·d),or the sludge recovery index RI increases to a high level(e.g.>16%)for a long time,it is suggested that the system is impacted and faces a great risk of accidents.Thereby,it is necessary to take measures to eliminate the effect of high concentration of chlorine in influent on activated sludge system.