微生物对饮用水典型消毒副产物前体物的降解效能及其群落特征

相对于CF（氯仿）等C-DBPs（含碳消毒副产物），DCAN（二氯乙腈）等N-DBPs（含氮消毒副产物）具有更高的毒性.控制DBPs（消毒副产物）的前体物是抑制DBPs产生的最有效方法之一.为考察微生物降解DBPs前体物对生成DBPs的影响，分别选取C-DBPs和N-DBPs的典型代表物CF和DCAN及其相应的典型前体物Tyr（酪氨酸）和Asp（天冬氨酸）为研究对象，采用微生物培养前体物的方式，探究微生物对典型前体物Tyr和Asp的降解效果及其对生成CF和DCAN的控制效果.结果表明:①Tyr和Asp两种前体物经微生物降解后，DOC（溶解性有机碳）的去除率分别为94.0%和85.6%，DON（溶解性有机氮）的去除率分别为69.0%和81.0%.②在前体物经微生物降解后的水样中，氯化或氯胺化消毒后生成CF和DCAN的量较降解前均大大减少.以Tyr为前体物，水样经微生物降解、氯化消毒后生成CF和DCAN的量分别降低了56.1%和89.5%，氯胺化消毒后生成CF的量降低了68.5%；以Asp为前体物，水样经微生物降解、氯化消毒后生成DCAN的量最高可降低99.9%，经微生物降解、氯胺化消毒后生成的CF可降低50.7%.③对水样中微生物菌群分析发现，在门水平上的菌群主要有变形菌门（Proteobacteria）、放线菌门（Actinobacteria）和拟杆菌门（Bacteroidetes），在属水平上的菌属主要有伯克氏菌属（Burkholderia-paraburkholderia）、半角藻属（Haliangium）、分枝杆菌属（Mycobacterium）、沉积小杆菌属（Sediminibacterium）、norank_f_Chitinophagaceae和动胶菌属（Zoogloea）.研究显示，微生物降解对DBPs典型前体物Tyr和Asp的去除，以及对生成CF和DCAN的控制具有较大的潜力，变形菌和放线菌在降解DBPs前体物中起到了重要作用. 

Degradation of Precursors of Typical Disinfection Byproducts in Drinking Water by Microorganisms and Its Microbial Communities

N-DBPs (e.g. DCAN) have received more attention in recent years, which were reported to be more toxic than C-DBPs (e.g. CF). One of the most effective ways to control the formation of DBPs was to remove its precursors before disinfection. To investigate the effect of microbial degradation on the formation of DBPs during subsequent chlorination and chloramination from DBPs precursors, this study selected CF and DCAN as the representative C-DBPs and N-DBPs, and selected Asp (aspartic acid) and Tyr (tyrosine) as the typical precursors to explore the effect of microbial degradation on the formation of DBPs. The results showed that after the degradation of Tyr and Asp, the removal rate of DOC was 94.0% and 85.6%, respectively, and the removal rate of DON was 69.0% and 81.0%, respectively. The amount of CF and DCAN during chlor(am)ination decreased greatly after biodegradation. The highest removal rates of CF and DCAN were reached 56.1% and 89.5% respectively when Tyr water sample was chlorinated. And the amount of CF was reduced by 68.5% for Tyr water sample during chloramination. For Asp water sample, the removal rate of DCAN reached 99.9% during chlorination, and the amount of CF reduced by 50.7% during chloramination. The microbial communities in water samples were analyzed. At the phylum level, Proteobacteria、Actinobacteria and Bacteroidetes were the dominant phylum. At the genus level, Burkholderia-paraburkholderia、Haliangium、Mycobacterium、Sediminibacterium、norank_f_chitinophagaceae and Zoogloea were the dominant genus. The research showed that biodegradation has great potential in controlling the formation of C-DBPs and N-DBPs. It is necessary to carry out the research on the control of multi-DBPs precursors by microbial degradation to realize the integrated control of DBPs.