title: UV/persulfate preoxidation to improve coagulation efficiency of Microcystis aeruginosa.
abstract: The performance of UV-activated persulfate (UV/PS) technology as preoxidation process to enhance Microcystis aeruginosa removal by subsequent coagulation-sedimentation was firstly evaluated. The results demonstrate that UV/PS preoxidation could successfully promote coagulation of algae cells through the effective neutralization of zeta potential, which was caused by the changes of cell morphology, size distribution and surface properties after simultaneous UV irradiation and formed reactive species (i.e. SO4-and HO) oxidation. Since excessive oxidation would cause cell rupture along with the release of organics, which could deteriorate coagulation efficiency, optimal PS dose (60mg/L) and UV dose (375mJ/cm2) were proposed to exist in this study. The concentrations of extracellular algal organic matter (AOM) sharply increased by 48.2% during the preoxidation period, while gradually decreased in the following coagulation and sedimentation. Most of the concerned disinfection by-products (DBPs) monotonically decreased or followed fluctuant reduction with increasing PS doses, whereas the trichloromethane, trichloroacetic acid and dichloroacetonitrile persistently increased, which was inferred to be related to the variation of AOM. This study suggests that UV/PS might be a potential pretreatment process to assist coagulation on the removal of algae.
authors: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China.
authors: Yiqun
authors: Y
authors: Chen
authors: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China. Electronic address: pengchao.x@gmail.com.
authors: Pengchao
authors: P
authors: Xie
authors: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China. Electronic address: zongpingw@hust.edu.cn.
authors: Zongping
authors: Z
authors: Wang
authors: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China; Department of Sanitary Engineering, Delft University of Technology, P.O. Box 5 Box 5048, 2600 GA Delft, The Netherlands.
authors: Ran
authors: R
authors: Shang
authors: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China.
authors: Songlin
authors: S
authors: Wang
mesh_terms: D057097:Harmful Algal Bloom; D046931:Microcystis / Q000187:drug effects / Q000302:isolation & purification* / Q000528:radiation effects; D010084:Oxidation-Reduction; D013431:Sulfates / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D013431:Sulfates
keywords: Coagulation; Disinfection by-products; Microcystis aeruginosa; Preoxidation; Ultraviolet/persulfate