复活光照强度对再生水紫外线消毒后大肠杆菌和粪大肠杆菌光复活的影响

Effect of Photoreactivating Light Intensity on Photoreactivation of Escherichia coli and Fecal Coliform in the Tertiary Effluent Disinfected by UV

研究了复活光照强度对污水三级处理出水紫外线消毒后大肠杆菌和粪大肠杆菌光复活的影响。复活光强对复活的影响依消毒时紫外线剂量及菌种的不同而不同.不同复活光强（0～43μW/cm^2）下，大肠杆菌在5 mJ/cm^2的紫外线剂量消毒后，复活情况基本不受复活光强影响.紫外线剂量增高至20 mJ/cm^2后复活光强存在阈值，在43μW/cm^2复活光条件下检测到明显的光复活，低于此光强没有检测到明显的光复活，粪大肠杆菌的光复活基本不受复活光照强度的影响.复活光强对细菌光复活的不同影响在光复活控制措施提出过程中需要考虑。

The effect of photoreaetivating light intensity on photoreactivation of E. coli and fecal coliform in tertiary effluent after UV disinfection were investigated. The response of the two species to intensity of photoreactivating light varied with UV dose and bacterial species. Photoreactivation of E. coil after UV irradiation of 5 mJ/cm^2 achieved the same maximum under three selected intensities of photoreactivating light（0-43 μW/cm^2 ） . A threshold existed when UV dose increased to 20 mJ/cm^2 and significant photoreactivation was detected only under intensity of light 43 μW/cm^2. With different UV doses irradiation, fecal coliform showed little difference under selected intensities of t photoreaetivating light in this study. The different effects of photoreactivating light intensity on photoreactivation of different bacteria should be considered when proposing the control measurements.