紫外消毒出水的微生物光复活及其控制技术

Study on Control of Microorganism Photoreactivation during UV Disinfection of Wastewater

污水厂出水经紫外线(UV)消毒后在排放过程中会出现微生物的复活现象,为此考察了采用UV—氯和UV—过氧乙酸(PAA)控制光复活的效果。经研究发现:在UV照射剂量为5.4mJ/cm2、投氯量为2.5 mg/L、反应时间为10 m in和UV照射剂量为5.4 mJ/cm2、过氧乙酸投量为10 mg/L、反应时间为10 m in的条件下,对大肠菌群的灭活率均可达4个对数级以上,并能控制光复活现象。从消毒稳定性、经济适用性、安全毒副性等方面考虑,可采用UV—PAA作为污水厂出水消毒及抑制光复活的技术。

After ultraviolet radiation disinfection of the effluent from WWTP, microorganisms can revivify due to the photoreactivation effects. This study is aimed to control photoreactivation by applying chlorine, peracetic acid （PAA） and UV disinfection. It is found that more 4-1g reduction of E. coli is achieved when the contact time is 10 min and UV dose is 5.4 mJ/cm^2. Meanwhile, with the combination of either 2.5 mg/L of chlorine or 10 mg/L of PAA, photoreactivation of E. coli can be controlled. Considering economics and security, UV -PAA is regarded as efficient and feasible for wastewater disinfection.