State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, People's Republic of China.
Institute of Water Environment Technology, MCC Huatian Engineering and Technology Corporation, Nanjing, People's Republic of China.
Environ Technol. 2022 Sep;43(21):3212-3220. doi: 10.1080/09593330.2021.1918263. Epub 2021 May 2.
Chlorine and chloramine are widely used to maintain the microbial safety after drinking water treatment plants. Particles existing in the treated water may react with these chemical disinfectants, and impact the efficacy of disinfection. However, the protective effects of particles without-disinfectant demand on bacteria in the chlorination/chloramination are not well known. In this study, two laboratory-derived bacteria ( and ) and two no-disinfectant demand particles (FeO and kaolin) in drinking water were selected to build particle-associated bacteria (PAB) systems, and their resistance to chlorine/chloramine was further assessed. Flow cytometry (FCM) was employed to image PAB systems and assess the removal rate of bacteria. The results were that particles showed protective effects on bacteria in half of chlorine experiments and 90% of chloramination. The protection was related to the combination form of particles and bacteria tied to neither particle species nor size, and there was no positive relationship between the protection effect and water turbidity. attached to FeO had stronger resistance than kaolin, and kaolin protected better than FeO. The same trend was observed in both chemical disinfectants, and more significant resistance had been shown in chloramination than chlorination. FCM images which gave a qualitative description on the combination states of different PAB systems may be a clue to explain the strength of the resistance. Environmental bacterial strains and particles are recommended in the future to explore practical applications.
氯和氯胺被广泛用于饮用水处理厂之后保持微生物安全。处理水中存在的颗粒可能会与这些化学消毒剂发生反应，并影响消毒效果。然而，颗粒对消毒无需求的细菌在氯化/氯胺中的保护作用还不清楚。在这项研究中，选择了两种实验室衍生的细菌（ 和 ）和两种饮用水中的无消毒需求颗粒（FeO 和高岭土）来构建颗粒相关细菌（PAB）系统，并进一步评估了它们对氯/氯胺的抵抗力。流式细胞术（FCM）用于对 PAB 系统成像并评估细菌的去除率。结果表明，在一半的氯实验和 90%的氯胺实验中，颗粒对细菌表现出保护作用。这种保护与颗粒和细菌的结合形式有关，与颗粒种类和大小无关，并且保护效果与水浊度之间没有正相关关系。与 FeO 结合的 具有比高岭土更强的抵抗力，而高岭土的保护效果比 FeO 更好。在两种化学消毒剂中都观察到了相同的趋势，并且氯胺中的抵抗力比氯化更强。FCM 图像对不同 PAB 系统的结合状态进行了定性描述，可能是解释抵抗力强度的线索。未来建议使用环境细菌菌株和颗粒来探索实际应用。
