污水内源性消毒副产物前体物的生成与识别

Generation and Characterization of Endogenous Precursors of Disinfection By-products from Sewage

污水生化处理过程中微生物生长代谢会分泌大量有机物,对消毒副产物的生成势产生一定影响。微生物在初始阶段利用葡萄糖基质维持自身生长代谢生成基质利用相关产物(UAP),UAP中氨基酸、多肽、蛋白质和芳香类化合物的相对含量较高;随着基质的消耗,待基质消耗殆尽后微生物进入衰亡期,细胞内有机物裂解释放以及胞外聚合物水解产生多糖、蛋白质、腐殖质和富里酸类物质,该阶段的产物为生物量相关产物(BAP)。SMPs、BAP与UAP分别经过氯消毒后,单位DOC所产生的含碳消毒副产物的含量远大于含氮消毒副产物,且三氯甲烷的生成量所占比例最大;含氮消毒副产物种类中DCAN所占比例较大。SMPs、UAP和BAP经氯消毒后副产物总产量的大小关系为SMP>BAP>UAP;对于THM和CH 2种含碳消毒副产物,BAP中含碳消毒副产物的生成势高于UAP;然而对于DCAN与TCNM 2类含氮消毒副产物来说,UAP中含氮消毒副产物生成势高于BAP。

A large amount of organic matter would be secreted during microbial growth and metabolism in biochemical treatment process of sewage,which could attribute the formation potential of Disinfection By-Products(DBPs).In the initial stage,glucose matrix was utilized to maintain microorganisms’growth and metabolism to produce matrix Utilization Associated Products(UAP).The relative content of amino acids,peptides,proteins,and aromatic compounds in UAP was relatively high;with the consumption of matrix,the microorganisms were depleted after the matrix was consumed.Into the decline phase,the release of intracellular organic matter and the hydrolysis of extracellular polymers produce polysaccharides,proteins,humic substances,and fulvic acids.The product of this stage was Biomass Associated Product(BAP).After SMPs,BAP and UAP were sterilized by chlorine respectively,the content of carbon-contained DBPs(C-DBPs)produced by unit DOC was much larger than that of nitrogen-contained DBPs(N-DBPs).The proportion of chloroform was the largest in C-DBPs while DCAN had a large proportion in N-DBPs.The relationship between the total yield of by-products of SMPs,UAP and BAP after chlorine disinfection was SMP>BAP>UAP;for the two C-DBPs of THM and CH,the formation potential of C-DBPs in BAP was higher than that of UAP;For both DCAN and TCNM N-DBPs,the formation of N-DBPs in UAP was higher than that of BAP.