微囊藻毒素-LR的臭氧降解研究

采用不同的臭氧投加量,考察了微囊藻毒素-LR(MC-LR)的降解效果,并通过对臭氧氧化过程中产生的8种主要降解产物的相对分子质量分析,推测其降解途径.结果表明,臭氧氧化降解MC-LR主要通过Adda途径和Mdha途径来完成对MC-LR的降解和脱毒作用.臭氧氧化的Adda途径是通过对MC-LR上Adda侧链的进攻,断开具有活性的Adda支链,而达到脱毒的目的;臭氧氧化的Mdha途径是通过对MCs肽环上面Mdha和Ala的断键,打开环状肽链,使藻毒素失去活性,在整个过程中Adda途径占主导地位.在O3∶MC为6时,MC-LR的去除率最高可达到92%.

Degradation of Microcystin-LR by Ozonation Process

Degradation and byproducts of microcystin-LR (MC-LR) under different ozone dosages were investigated, and,the pathway and mechanism for the degradation of MC-LR were also elucidated according to the molecular weight of 8 degradation byproducts during ozonation process in this paper. The results showed that there were two pathways for the degradation of MC-LR by ozone. The first one is that the diene structure in Adda side chain was attacked and cleaved, which was named as Adda degradation pathway. The second one is that the pathway of Mdha and Ala degradation, which was that the peptide bond between Mdha and Ala was attacked and cleaved. Adda degradation pathway was dominant and mainly responsible for the degradation of MC-LR by ozone. The removal of MC-LR by ozone could reach 92% when O_3 : MC is 6.