Schmidtlein F, Lübken M, Grote I, Orth H, Wichern M
Institute of Urban Water Management and Environmental Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum 44780, Germany E-mail:
Water Sci Technol. 2015;71(2):220-6. doi: 10.2166/wst.2014.488.
Photoreactivation of ultraviolet (UV)-disinfected wastewater of different qualities was experimentally assessed. Photoreactivation ability of secondary effluent and microstrained inflow was analyzed in different samples of 50 mL (Petri dish) and 7,000 mL volume to describe open channel effluent situations of wastewater treatment plants in a more realistic approach. The small sample of secondary effluent revealed a total log10 inactivation of 1.8 units and the small sample of microstrained inflow a total log10 inactivation of 3.2, with an applied UV-254 fluence of 84 and 253 J/m², respectively. Maximum net photoreactivation for secondary effluent and microstrained inflow was in the order of 1.2 log10 and 0.37 log10 units, respectively, for both sample sizes. However, significantly faster photoreactivation performance was generally determined for small sample volumes. The photoreactivation processes were completely compensated for by solar disinfection within a 120 min exposure time. Solar disinfection processes were negligible in the larger sample volumes of microstrained inflow. For municipal wastewater treatment systems with open channel effluents, it is essential to take into consideration the dependence of solar UV-365 fluence rate on water depth and wastewater characteristics.
对不同水质的紫外线（UV）消毒废水的光复活作用进行了实验评估。在50毫升（培养皿）和7000毫升体积的不同样品中分析了二级出水和微滤进水的光复活能力，以便更实际地描述污水处理厂的明渠出水情况。二级出水的小样品显示总对数10灭活为1.8个单位，微滤进水的小样品总对数10灭活为3.2，紫外线254通量分别为84和253 J/m²。对于两种样品大小，二级出水和微滤进水的最大净光复活分别约为1.2对数10和0.37对数10单位。然而，通常确定小样品体积的光复活性能明显更快。在120分钟的暴露时间内，光复活过程被太阳能消毒完全抵消。在微滤进水的较大样品体积中，太阳能消毒过程可忽略不计。对于具有明渠出水的城市污水处理系统，必须考虑太阳紫外线365通量率对水深和废水特性的依赖性。
