Abstract：
Disinfection is a necessity in water and wastewater treatment and reclamation. This study examined the inactivation of a disinfectant resistant but widely existed opportunistic pathogen in reclaimed water, Staphylococcus aureus (S. aureus), by sequential UV and chlorine disinfection or simultaneous UV and chlorine disinfection (UV/Cl). It was identified that UV/Cl greatly promoted the inactivation efficacy and inhibited photoreactivation of S. aureus by the generation of free radicals (i.e. OH and Cl), which reached a 7-log10 reduction at UV and chlorine doses of 18 mJ/cm2 and 2 mg-Cl/L, respectively. The changes of bacterial viability and morphology and the increase of extracellular ATP concentration confirmed the enhancement of cell membranes damages (>21.4 %) due to free radicals generated in UV/Cl process, which caused a dramatic reduction in metabolic activity and suppressed the photoreactivation. Furthermore, this study demonstrated that UV/Cl effectively removed heterotrophic plate count bacteria and aromatic organic fluorophores in reclaimed water samples. This study is of significant theoretical and applicable importance in guaranteeing safe microbial levels for water reclamation and reuse.
摘要：
消毒是水和废水处理和再生的必要条件。这项研究检查了再生水中耐消毒剂但广泛存在的机会性病原体的失活，金黄色葡萄球菌（S。金黄色葡萄球菌)，通过顺序紫外线和氯消毒或同时紫外线和氯消毒（UV/Cl）。经鉴定,UV/Cl通过自由基(即OH和Cl)的产生,极大地促进了金黄色葡萄球菌的失活效力并抑制了光再活化,在18mJ/cm2和2mg-Cl/L的紫外线和氯剂量下达到7-log10的降低，分别。细菌活力和形态的变化以及细胞外ATP浓度的增加证实了由于UV/Cl过程中产生的自由基引起的细胞膜损伤的增强(>21.4%)。这导致了代谢活动的急剧减少并抑制了光活化。此外，这项研究表明，UV/Cl可以有效地去除再生水样品中的异养平板计数细菌和芳香族有机荧光团。这项研究对于保证水回收和再利用的安全微生物水平具有重要的理论和应用意义。
