Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), State Key Laboratory of Marine Pollution & Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China.
Water Res. 2021 Feb 15;190:116705. doi: 10.1016/j.watres.2020.116705. Epub 2020 Nov 30.
To evaluate the green photocatalytic disinfection for practical applications, disinfection of different types of real sewage using magnetic photocatalyst RGO/Fe,N-TiO/FeO@SiO (RGOFeNTFS) under simulated solar light was investigated: low-salinity sewage after tertiary treatment, low-salinity sewage after secondary biological treatment, high-salinity sewage after secondary biological treatment, and high-salinity sewage after chemically enhanced primary treatment. The classification of the sewage as high and low-salinity is based on the regions of sewage source that use seawater and freshwater for toilet flushing, respectively. It shows potential of solar-light-driven photocatalytic disinfection in low-salinity sewage: around 20 min (for sewage after tertiary treatment) and 45 min (for sewage after secondary treatment) of photocatalytic disinfection are required for sewage to meet the discharge standard, and no bacterial regrowth is observed in the treated sewage after 48 h. However, due to the poorer water quality, the high-salinity sewage requires a relatively long reaction time (more than 240 min) to meet the discharge standard, showing minimal practical significance. Further, the complex characteristics of real sewage, such as organic matter, suspended matter, multivalent-ions, pH and DO level significantly influence photocatalytic disinfection, and should be carefully reviewed in evaluating the photocatalytic disinfection of sewage. Besides, RGOFeNTFS shows a good reusability over three cycles for photocatalytic disinfection of low-salinity sewage samples. Moreover, the non-toxicity, indicated by phytoplankton in seawater, of both RGOFeNTFS (<= 3 g/L) and treated low-salinity sewage demonstrates the feasibility of the practical application of photocatalytic disinfection using RGOFeNTFS under irradiation of solar light.
为了评估实际应用中的绿色光催化消毒效果，使用磁性光催化剂 RGO/Fe,N-TiO/FeO@SiO（RGOFeNTFS）在模拟太阳光下对不同类型的实际污水进行了消毒：经过三级处理的低盐度污水、经过二级生物处理的低盐度污水、经过二级生物处理的高盐度污水和经过化学增强一级处理的高盐度污水。污水的高低盐度分类是基于分别使用海水和淡水冲洗厕所的污水源区域。它显示了太阳能驱动光催化消毒在低盐度污水中的潜力：对于经过三级处理的污水，需要大约 20 分钟（对于经过二级处理的污水，需要大约 45 分钟）的光催化消毒即可达到排放标准，并且在处理后的污水中 48 小时内没有细菌再生。然而，由于水质较差，高盐度污水需要较长的反应时间（超过 240 分钟）才能达到排放标准，实际意义不大。此外，实际污水的复杂特性，如有机物、悬浮物、多价离子、pH 值和 DO 水平，会显著影响光催化消毒，在评估污水的光催化消毒时应仔细审查。此外，RGOFeNTFS 在用于低盐度污水样品的光催化消毒的三个循环中表现出良好的可重复使用性。此外，海水浮游植物表明，RGOFeNTFS（<= 3 g/L）和处理后的低盐度污水均无毒，这表明在太阳光照射下使用 RGOFeNTFS 进行光催化消毒具有实际应用的可行性。
