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.)