Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, CA, 94305, USA.
City of Los Angeles, USA.
Water Res. 2019 Apr 1;152:215-225. doi: 10.1016/j.watres.2018.12.062. Epub 2019 Jan 11.
Ozone and biological activated carbon (O/BAC) is being considered as an alternative advanced treatment process to microfiltration and reverse osmosis (MF/RO) for the potable reuse of municipal wastewater. Similarly, the UV/free chlorine (UV/HOCl) advanced oxidation process (AOP) is being considered as an alternative to the UV/hydrogen peroxide (UV/HO) AOP. This study compared the performance of these alternative treatment processes for controlling N-nitrosamines and chloramine-reactive N-nitrosamine and halogenated disinfection byproduct (DBP) precursors during parallel, pilot-scale treatment of tertiary municipal wastewater effluent. O/BAC outperformed MF/RO for controlling N-nitrosodimethylamine (NDMA), while MF/RO was more effective for controlling N-nitrosomorpholine (NMOR) and chloramine-reactive NDMA precursors. The UV/HO and UV/HOCl AOPs were equally effective for controlling N-nitrosamines in O/BAC effluent, but UV/HOCl was less effective for controlling NDMA in MF/RO effluent, likely due to the promotion of dichloramine under these conditions. MF/RO was more effective than O/BAC for controlling chloramine-reactive halogenated DBP precursors on both a mass and toxicity-weighted basis. UV/HO AOP treatment was more effective at controlling the toxicity-weighted chloramine-reactive DBP precursors for most halogenated DBP classes by preferentially degrading the more toxic brominated species. However, the total toxicity-weighted DBP precursor concentrations were similar for treatment by either AOP because UV/HO AOP treatment promoted the formation of iodoacetic acid, which exhibits a very high toxic potency. The combined O/BAC/MF/RO train was the most effective for controlling N-nitrosamines and the total toxicity-weighted DBP precursor concentrations with or without treatment by either AOP.
臭氧和生物活性炭（O/BAC）被认为是微滤和反渗透（MF/RO）的替代高级处理工艺，可用于市政废水的饮用水再利用。同样，紫外线/自由氯（UV/HOCl）高级氧化工艺（AOP）也被认为是替代紫外线/过氧化氢（UV/HO）AOP 的方法。本研究比较了这些替代处理工艺在平行中试规模处理三级市政废水时控制 N-亚硝胺和氯胺反应性 N-亚硝胺以及卤代消毒副产物（DBP）前体的性能。O/BAC 在控制 N-亚硝基二甲胺（NDMA）方面优于 MF/RO，而 MF/RO 对控制 N-亚硝基吗啉（NMOR）和氯胺反应性 NDMA 前体更有效。UV/HO 和 UV/HOCl AOP 对控制 O/BAC 出水中的 N-亚硝胺同样有效，但 UV/HOCl 对控制 MF/RO 出水中的 NDMA 效果较差，这可能是由于在这些条件下促进了二氯胺的形成。MF/RO 比 O/BAC 更有效地控制基于质量和毒性加权的氯胺反应性卤代 DBP 前体。UV/HO AOP 处理在优先降解毒性更高的溴代物种的情况下，对大多数卤代 DBP 类别更有效地控制毒性加权的氯胺反应性 DBP 前体。然而，由于 UV/HO AOP 处理促进了碘乙酸的形成，而碘乙酸表现出非常高的毒性，因此两种 AOP 处理的总毒性加权 DBP 前体浓度相似。O/BAC/MF/RO 联合处理对于控制 N-亚硝胺和总毒性加权 DBP 前体浓度最有效，无论是否进行 AOP 处理。
