Water Science and Technology Group (WaSTe), Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
Water Science and Technology Group (WaSTe), Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
Sci Total Environ. 2024 Jan 10;907:167940. doi: 10.1016/j.scitotenv.2023.167940. Epub 2023 Oct 22.
The aim of this study was to investigate the interference of polyethylene microplastics (MPs) on ultraviolet irradiation/hydrogen peroxide (UV/HO) and ozonation processes in the inactivation of E. coli bacteria (tertiary treatment) and removal of contaminants of emerging concern (CECs) (quaternary treatment) from simulated and real secondary treated urban wastewater. Three pharmaceuticals were investigated as model CECs, namely carbamazepine, sulfamethoxazole and trimethoprim. Experimental results showed that disinfection efficiency of UV/HO treatment decreased (2.4, 1.8 and 1.3 log reductions of E. coli, initial HO dose of 30 mg/L, 2.5 min treatment) as the initial concentration of MPs was increased (0.25, 0.5 and 1.0 g/L, respectively). Similarly, an increase in MPs concentration (0.25, 0.5 and 1.0 g/L) reduced the inactivation (4.7, 4.1 and 3.7 log reductions) of the target bacteria after 60 min of ozonation treatment. Although the disinfection efficiency of both treatment processes was negatively affected by the presence of MPs, UV/HO was more effective than the ozonation, despite ozonation being investigated at high doses to better discriminate the effect of MPs. Noteworthy, CECs degradation by UV/HO under realistic operating conditions was affected to some extent by MPs, while a lower effect was observed for ozonation, at not realistic ozone dose.
本研究旨在探讨聚乙烯微塑料 (MPs) 对紫外线辐照/过氧化氢 (UV/HO) 和臭氧氧化工艺的干扰，以评估其在灭活大肠杆菌（三级处理）和去除新兴污染物（CECs）（四级处理）方面的效果，该研究采用模拟和实际二级处理城市废水进行。三种药物被选为模型 CECs，分别为卡马西平、磺胺甲恶唑和甲氧苄啶。实验结果表明，随着 MPs 初始浓度的增加（分别为 0.25、0.5 和 1.0 g/L），UV/HO 处理的消毒效率降低（大肠杆菌的灭活率分别降低了 2.4、1.8 和 1.3 个对数），初始 HO 剂量为 30 mg/L，处理时间为 2.5 分钟。同样，随着 MPs 浓度的增加（分别为 0.25、0.5 和 1.0 g/L），臭氧处理 60 分钟后目标细菌的灭活率（4.7、4.1 和 3.7 个对数）也降低。尽管两种处理工艺的消毒效率均受到 MPs 的负面影响，但 UV/HO 比臭氧氧化更有效，尽管臭氧氧化在高剂量下进行，以更好地区分 MPs 的影响。值得注意的是，在实际运行条件下，UV/HO 对 CECs 的降解在一定程度上受到 MPs 的影响，而在不现实的臭氧剂量下，臭氧氧化的影响较小。
