紫外氯胺组合消毒供水系统中病毒微生物的分布特征

为研究紫外氯胺组合消毒对供水系统中病毒微生物的影响特性，以生产规模紫外氯胺组合消毒供水系统为研究对象，应用宏基因组技术对供水系统中病毒微生物的迁移变化、群落结构和病毒宿主进行了分析.结果表明，紫外氯胺组合消毒工艺能降低病毒物种数（6.13%）和基因丰度（51.97%），但不能完全去除水中病毒微生物.对比美国环保署（USEPA）以培养法检测的水处理病毒去除率可达99%~99.99%，本研究利用宏基因组技术测得的总病毒去除率只有93.46%，以培养法检测水中病毒存在局限性.Caudovirales（有尾噬菌体目）是整个供水系统中最丰富病毒，对氯胺消毒都具有一定敏感性.Lentivirus（慢病毒属）作为能够感染人和脊椎动物的病毒，对紫外照射和氯胺消毒都具有强抵抗力.该供水系统中最大的病毒宿主是细菌（61.50%）.原水中病毒主要寄生在Synechococcus（聚球藻属）中；出厂水以及管网水中，优势病毒宿主均为Pseudomonas（假单胞菌属）；进入管网后，Pseudomonas aeruginosa（铜绿假单胞菌）宿主病毒基因丰度升高342.62%，应加强关注管网系统病毒微生物风险.紫外氯胺组合消毒工艺比单紫外消毒更有利于病毒宿主的去除（51.97%与0.79%）.

Distribution Characteristics of Viruses Microorganisms in a Water Supply System with Combined Ultraviolet Chloramine Disinfection

To study the effect of combined ultraviolet (UV) chloramine disinfection on viruses in a drinking water supply system, a full-scale experiment was conducted to analyze the distribution, variability, community structure, and hosts of viruses using metagenomics. The results showed that the combined UV chloramine process reduced the number of virus species (6.13%) and gene abundance (51.97%) but did not completely remove the viruses from the water. The United States Environmental Protection Agency (USEPA) report that virus removal efficiencies from water can reach 99%-99.99% based on culturing methods. However, in this study, metagenomic analysis indicated a total virus removal rate of only 93.46%. Therefore, the detection of viruses in water using culturing method cannot reliably detect viruses in drinking water. Caudovirales are the most abundant type of virus in water supply systems and are sensitive to chloramine disinfection. Lentivirus, as a virus that can infect humans and vertebrates, has strong resistance to UV and chloramine disinfection. The main virus hosts in the studied water supply system were bacteria (61.50%). The viruses in the raw water were mainly parasitic in Synechococcus. The dominant virus host was Pseudomonas in both the effluent water and pipe network water. The gene abundance of the Pseudomonas aeruginosa host in the pipe network increased by 342.62%, which requires further attention as a virus risk in pipe network systems. Overall, combined UV chloramine disinfection was more effective at the removal of virus hosts than single UV disinfection (51.97% compared to 0.79%).