Study on the removal and degradation mechanism of microcystin-LR by the UV/Fenton system

Zhuang Li; Jiling Chen; Canmei Wang; Jinjin Zhao; Qun Wei; Xiangmeng Ma; Gairen Yang

doi:10.1016/j.scitotenv.2023.164665

Study on the removal and degradation mechanism of microcystin-LR by the UV/Fenton system

Sci Total Environ. 2023 Sep 20:892:164665. doi: 10.1016/j.scitotenv.2023.164665. Epub 2023 Jun 3.

Authors

Zhuang Li¹, Jiling Chen¹, Canmei Wang¹, Jinjin Zhao¹, Qun Wei¹, Xiangmeng Ma², Gairen Yang³

Affiliations

¹ School of Resources, Environment and Materials, Guangxi University, No. 100 Daxue Road, Nanning, Guangxi 530004, PR China.
² School of Resources, Environment and Materials, Guangxi University, No. 100 Daxue Road, Nanning, Guangxi 530004, PR China; Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, No. 100 Daxue Road, Nanning 530004, PR China. Electronic address: maxiangmeng@gxu.edu.cn.
³ Forestry College of Guangxi University, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, No. 100 Daxue Road, Nanning 530004, PR China.

PMID: 37277039
DOI: 10.1016/j.scitotenv.2023.164665

Abstract

Microcystin-LR (MC-LR) is highly hepatotoxic and potentially carcinogenic to humans. Therefore, removing MC-LR from water bodies is of paramount importance. This study aimed to investigate the removal efficacy of the UV/Fenton system on MC-LR from copper-green microcystin and to explore its degradation mechanism in simulated real algae-containing wastewater. The results showed that at an initial concentration of 5 μg·L^-1, a combination of 300 μmol·L^-1 H₂O₂, 125 μmol·L^-1 FeSO₄, and 5 min of UV irradiation under average radiation intensity of 48 μW·cm^-2 resulted in a removal efficiency of 90.65 % for MC-LR. The reduction of extracellular soluble microbial metabolites of Microcystis aeruginosa confirmed the UV/Fenton method's degradation efficiency for MC-LR, while the observation of the functional group CH and OCO in the treatment group indicated effective binding sites in the coagulation process. However, the presence of humic substances in algal organic matter (AOM) and some proteins and polysaccharides in the algal cell suspension competed with MC-LR for HO·, resulting in a decreased removal effect (78.36 %) in simulated actual algae-containing wastewater. These quantitative results provide an experimental basis and theoretical foundation for controlling cyanobacterial water blooms and ensuring drinking water quality safety.

Keywords: Cyanobacterial bloom control; Drinking water quality safety; MC-LR quantification; MC-LR removal; UV/Fenton.

MeSH terms

Humans
Hydrogen Peroxide / chemistry
Microcystins / analysis
Microcystis*
Wastewater
Water Purification* / methods

Substances

cyanoginosin LR
Microcystins
Hydrogen Peroxide
Wastewater