Abstract：
UV/peroxymonosulfate (UV/PMS) advanced oxidation process has attracted significant attention for removal of micropollutants in water. However, during practical water treatment applications, the PMS treatment must be performed before the UV treatment to achieve full contact. In this study, sulfamethoxazole (SMX) was selected as the target micropollutant. Four different operational approaches, including UV alone, PMS alone, simultaneous UV/PMS and sequential PMS-UV, were compared for their differences in SMX removal and disinfection by-product (DBP) formation potentials during chlorine-driven disinfection. Among the four approaches, UV/PMS and PMS-UV achieved over 90% removal efficiencies for SMX without substantial differences. For raw water, the trichloronitromethane (TCNM) formation potential after treatment with PMS-UV was lower than that after UV/PMS treatment. The time interval over which the PMS-UV process was conducted had little effect on the final removal efficiency for SMX. However, a brief (5 min) pre-PMS treatment significantly reduced the TCNM formation potential and the genotoxicity from DBPs. The formation risk for TCNM during chlorination increased markedly with increasing PMS dosages, and the appropriate dosage under these experimental conditions was suggested to be 0.5-1.0 mmol/L. Under alkaline conditions, PMS-UV treatment can enhance SMX degradation as well as dramatically reduced the formation potentials for haloketones, haloacetonitriles and halonitromethanes. This study suggests that proper optimization of UV/PMS processes can remove SMX and reduce its DBP formation.
摘要：
UV/过氧单硫酸盐(UV/PMS)高级氧化工艺在去除水中微污染物方面受到了广泛关注。然而,在实际的水处理应用中，必须在UV处理之前进行PMS处理以实现完全接触。在这项研究中,选择磺胺甲恶唑（SMX）作为目标微污染物。四种不同的操作方法，包括紫外线，仅PMS,同时UV/PMS和顺序PMS-UV，比较了氯驱动消毒过程中SMX去除和消毒副产物（DBP）形成电位的差异。在这四种方法中，对于SMX,UV/PMS和PMS-UV实现了超过90%的去除效率,而没有实质性差异。对于原水，PMS-UV处理后的三氯硝基甲烷（TCNM）形成潜力低于UV/PMS处理后的潜力。进行PMS-UV工艺的时间间隔对SMX的最终去除效率几乎没有影响。然而,短暂（5分钟）的PMS前处理显着降低了TCNM的形成潜力和DBPs的遗传毒性。氯化过程中TCNM的形成风险随着PMS剂量的增加而显著增加，在这些实验条件下的合适剂量建议为0.5-1.0mmol/L。在碱性条件下,PMS-UV处理可以增强SMX降解，并显着降低卤酮的形成潜力，卤代乙腈和卤代硝基甲烷。这项研究表明，适当优化UV/PMS工艺可以去除SMX并减少其DBP形成。
