Sgroi Massimiliano, Snyder Shane A, Roccaro Paolo
Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria 6, 95125, Catania, Italy.
Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ, 85721, USA; Nanyang Technological University, Nanyang Environment & Water Research Institute, 1 Cleantech Loop, CleanTech One, #06-08, 637141, Singapore.
Chemosphere. 2021 Jun;273:128527. doi: 10.1016/j.chemosphere.2020.128527. Epub 2020 Oct 9.
This work evaluated different advanced oxidation processes (AOPs) operated at pilot-scale as tertiary treatment of municipal wastewater in terms of energy efficiency, disinfection by-products formation and pathogens inactivation. Investigated AOPs included UV/HO, UV/Cl, O, O/UV, HO/O/UV, Cl/O/UV. AOPs were operated using various ozone doses (1.5-9 mg L), and UV fluences (191-981 mJ cm). Electrical energy costs necessary for the oxidation of contaminants of emerging concern (CEC) (i.e., carbamazepine, fluoxetine, gemfibrozil, primidone, sulfamethoxazole, trimethoprim) were calculated using the electrical energy per order (E) parameter. Ozonation resulted by far the most energy efficient process, whereas UV/HO and UV/Cl showed the highest energy costs. Energy costs for AOPs based on the combination of UV and ozone were in the order O/UV ≈ Cl/O/UV > HO/O/UV, and they were significantly lower than energy costs of UV/HO and UV/Cl processes. Cl/O/UV increased bromate formation, O/UV and O had same levels of bromate formation, whereas HO/O/UV did not form bromate. In addition, UV photolysis resulted an effective treatment for NDMA mitigation even in combination with ozone and chlorine in AOP technologies. Ozonation (doses of 1.5-6 mg L) was the least effective process to inactivate somatic coliphages, total coliform, escherichia coli, and enterococci. UV irradiation was able to completely inactivate somatic coliphages, total coliform, escherichia coli at low fluence (191 mJ cm), whereas enterococci were UV resistant. AOPs that utilized UV irradiation were the most effective processes for wastewater disinfection resulting in a complete inactivation of selected indicator organisms by low ozone dose (1.5 mg L) and UV fluence (191-465 mJ cm).
这项工作从中试规模运行的能源效率、消毒副产物形成和病原体失活方面，评估了不同的高级氧化工艺（AOPs）作为城市污水三级处理的情况。所研究的AOPs包括UV/HO、UV/Cl、O₃、O₃/UV、HO₂/O₃/UV、Cl₂/O₃/UV。AOPs使用不同的臭氧剂量（1.5 - 9 mg/L）和UV通量（191 - 981 mJ/cm²）运行。使用每级电能（E）参数计算了氧化新兴关注污染物（CEC）（即卡马西平、氟西汀、吉非罗齐、扑米酮、磺胺甲恶唑、甲氧苄啶）所需的电能成本。臭氧氧化是迄今为止最节能的工艺，而UV/HO和UV/Cl显示出最高的能源成本。基于UV和臭氧组合的AOPs的能源成本顺序为O₃/UV ≈ Cl₂/O₃/UV > HO₂/O₃/UV，且显著低于UV/HO和UV/Cl工艺的能源成本。Cl₂/O₃/UV增加了溴酸盐的形成，O₃/UV和O₃有相同水平的溴酸盐形成，而HO₂/O₃/UV不形成溴酸盐。此外，即使在AOP技术中与臭氧和氯结合，UV光解也能有效减轻NDMA。臭氧氧化（剂量为1.5 - 6 mg/L）是灭活体细胞噬菌体、总大肠菌群、大肠杆菌和肠球菌最无效的工艺。UV照射能够在低通量（191 mJ/cm²）下完全灭活体细胞噬菌体、总大肠菌群、大肠杆菌，而肠球菌对UV具有抗性。利用UV照射的AOPs是废水消毒最有效的工艺，通过低臭氧剂量（1.5 mg/L）和UV通量（191 - 465 mJ/cm²）可使选定的指示生物完全失活。
