Abstract：
Disinfection is essential in water and wastewater treatment process as a guarantee for microbial safety. This study systematically investigated: (i) the inactivation characteristics of bacteria widely existed in water, including Gram-negative bacteria (Escherichiacoli) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis spores), by sequential UV and chlorine disinfection processes (UV-Cl and Cl-UV), simultaneous UV and chlorine disinfection process (UV/Cl); and (ii) the disinfection mechanisms on different bacteria. The combination of UV and chlorine disinfection could inactive bacteria at lower doses, but showed no synergistic effect on E. coli. Contrarily, disinfection results indicated that UV/Cl performed an obvious synergistic effect on highly disinfectant-resistant bacteria (e.g. S. aureus and B. subtilis spores). Specifically, UV/Cl at the UV dose of 9 mJ/cm2 and chlorine dose of 2 mg-Cl/L could inactivate S. aureus completely. Moreover, the effectiveness of UV/Cl on the removal of indigenous bacteria in actual water conditions was also confirmed. In short, the study provides significant theoretical and practical implications for ensuring microbial safety during water treatment and use.
摘要：
消毒是水和废水处理过程中必不可少的，是保证微生物安全的保证。本研究系统考察了:(一)水中广泛存在的细菌的灭活特性,包括革兰氏阴性菌（大肠杆菌）和革兰氏阳性菌（金黄色葡萄球菌和枯草芽孢杆菌孢子），通过连续的紫外线和氯消毒过程（UV-Cl和Cl-UV），同时的紫外线和氯消毒过程（UV/Cl）；（ii）对不同细菌的消毒机制。紫外线和氯的联合消毒可以在较低剂量下灭活细菌，但对大肠杆菌没有协同作用。相反，消毒结果表明，UV/Cl对高度耐消毒剂的细菌（例如金黄色葡萄球菌和枯草芽孢杆菌孢子）具有明显的协同作用。具体来说,在9mJ/cm2的紫外线剂量和2mg-Cl/L的氯剂量下，UV/Cl可以完全灭活金黄色葡萄球菌。此外，还证实了UV/Cl在实际水条件下去除土著细菌的有效性。总之,该研究为确保水处理和使用过程中的微生物安全提供了重要的理论和实践意义。
