Acetylacetone effectively controlled the secondary metabolites of Microcystis aeruginosa under simulated sunlight irradiation  

作　　者：Xiaomeng Wang Yixin Luo Shujuan Zhang Lixiang Zhou 

机构地区：[1]Department of Environmental Engineering,College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China [2]The State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China

出　　处：《Journal of Environmental Sciences》2024年第1期285-295,共11页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.21906085);the Natural Science Foundation of Jiangsu Province of China (No.BK20190547);the State Key Laboratory of Pollution Control and Resource Reuse Foundation (No.PCRRF21046)。

摘　　要：Inactivation of cyanobacterial cells and simultaneous control of secondary metabolites is of significant necessity for the treatment of cyanobacteria-laden water.Acetylacetone(AcAc)has been reported a specific algicide to inactivate Microcystis aeruginosa(M.aeruginosa)and an effective light activator to degrade pollutants.This study systematically investigated the photodegradation ability of AcAc under xenon(Xe)irradiation on the secondary metabolites of M.aeruginosa,mainly algal organic matter(AOM),especially toxic microcystin-LR(MC-LR).Results showed that AcAc outperformed H_(2)O_(2)in destructing the protein-like substances,humic acid-like matters,aromatic proteins and fulvic-like substances of AOM.For MC-LR(250μg/L),0.05 mmol/L AcAc attained the same degradation efficiency(87.0%)as 0.1mmol/L H_(2)O_(2).The degradation mechanism of Xe/AcAc might involve photo-induced energy/electron transfer and formation of carbon center radicals.Alkaline conditions(pH>9.0)were detrimental to the photoactivity of AcAc,corresponding to the observed degradation rate constant(k_(1)value)of MC-LR drastically decreasing to 0.0013 min^(-1)as solution pH exceeded 9.0.The PO_(4)^(3-)and HCO_(3)^(-)ions had obvious inhibition effects,whereas NO_(3)^(-)slightly improved k_(1)value from 0.0277 min^(-1)to 0.0321 min^(-1).The presence of AOM did not significantly inhibit MC-LR degradation in Xe/AcAc system.In addition,the biological toxicity of MC-LR was greatly reduced after photoreaction.These results demonstrated that AcAc was an alternative algicidal agent to effectively inactivate algal cells and simultaneously control the secondary metabolites after cell lysis.Nevertheless,the concentration and irradiation conditions should be further optimized in practical application.

关 键 词：Microcystis aeruginosa PHOTODEGRADATION ACETYLACETONE Secondary metabolites MICROCYSTIN 

分 类 号：X52[环境科学与工程—环境工程]