College of Defense Engineering, The Army Engineering University of PLA, Nanjing, 210007, China.
College of Defense Engineering, The Army Engineering University of PLA, Nanjing, 210007, China.
Chemosphere. 2020 Mar;242:125190. doi: 10.1016/j.chemosphere.2019.125190. Epub 2019 Oct 31.
This paper studied stagnation-induced changes of disinfectant and bacteria using an orthogonal test and kinetic analysis, and then proposed a disinfection strategy. Tap water from a drinking water distribution system and ultrafiltrated water were collected and disinfected with four disinfectants (concentrations were set 0.2-1 mg/L as Cl. The study had several findings. First, disinfectants expanded lag phases and shortened generation times of the microbiome. Reduction in culturability, substrate responsiveness, respiratory activity, membrane potential and integrity subsequently occurred with increasing disinfection concentration. Second, the disinfectant decay rate decreased with initial disinfection concentration, and the effective disinfection phase (heterotrophic plate count (HPC) was less than 100 cfu/mL) was longer in water samples with lower organic matter. Moreover, the disinfection process was divided into an effective phase and an invalid phase (HPC>100 cfu/mL). Then a disinfection efficiency model was built and the regulation of disinfection by-products (DBPs) production was studied in chlorinated water samples, which provides a general method for other disinfectant studies. The average trihalomethanes (THMs) production during the effective phase (marked as THM/t) and THMs production during the invalid phase (marked as ΔTHM) were proposed to evaluate the DBPs production. The level of THM/t and ΔTHM were lower in ultrafiltrated water than those in tap water. THM/t were negatively correlated with initial chlorine concentration while ΔTHM were positively correlated with initial chlorine concentration. Finally, for the purpose of raising disinfection efficiency and decreasing DBPs, we propose periodic pulse disinfection.
本研究采用正交试验和动力学分析，研究了停滞诱导变化对消毒剂和细菌的影响，提出了一种消毒策略。采集饮用水分配系统中的自来水和超滤水，并用四种消毒剂（浓度设定为 0.2-1mg/L 作为 Cl）进行消毒。研究有几个发现。首先，消毒剂延长了微生物组的滞后期并缩短了世代时间。随着消毒浓度的增加，可培养性、基质响应性、呼吸活性、膜电位和完整性降低。其次，消毒剂的衰减速率随初始消毒浓度的增加而降低，在有机物含量较低的水样中，有效消毒阶段（异养平板计数（HPC）小于 100 cfu/mL）较长。此外，消毒过程分为有效阶段和无效阶段（HPC>100 cfu/mL）。然后建立了消毒效率模型，并研究了氯化水中消毒副产物（DBPs）的产生规律，为其他消毒剂的研究提供了一种通用方法。提出了有效阶段（标记为 THM/t）和无效阶段（标记为ΔTHM）的三卤甲烷（THMs）生成平均浓度来评估 DBPs 的生成。超滤水中的 THM/t 和ΔTHM 水平均低于自来水。THM/t 与初始氯浓度呈负相关，而ΔTHM 与初始氯浓度呈正相关。最后，为了提高消毒效率和降低 DBPs，我们提出了定期脉冲消毒。
