Simultaneous surface-adsorbed organic matter desorption and cell integrity maintenance by moderate prechlorination to enhance Microcystis aeruginosa removal in KMnO4Fe(II) process.
The KMnO4Fe(II) process was proved to have good application potential in Microcystis aeruginosa removal, although at relatively high doses. This study aims to improve the algae removal in KMnO4Fe(II) process by moderate prechlorination, which can realize the desorption of surface-adsorbed organic matter (S-AOM) from algae cells without damaging cell integrity. S-AOM was proved to not only inhibit algae removal but also maintain cell integrity, using various dilution methods for algal suspension preparation. The dilution after filtration method mainly removed the dissolved organics in cultured M. aeruginosa, while the dilution after centrifugal cleaning method could also remove the S-AOM on algae cells. Compared with the S-AOM-removed algal suspension, the lower algae removal in KMnO4Fe(II) process and the reduced proportion of damaged cells during prechlorination of algal suspension without S-AOM removed indicated the inhibitory role of S-AOM in algae removal and the protective function of S-AOM toward cell integrity, respectively. Moderate prechlorination of directly diluted M. aeruginosa could be realized at chlorine doses of below 0.5 mg/L, and the damaged cell ratios were below 4% after 5-min prechlorination. The ability of the KMnO4Fe(II) process to remove algae was dramatically enhanced by the elevation of chlorine dose from 0 to 0.5 mg/L, as more S-AOM was desorbed during prechlorination. Additionally, algae cells were easily captured by flocs after moderate prechlorination, which benefited the floc aggregation for formation of tightly bounded algae flocs. Therefore, the desorption of S-AOM without damaging cell integrity is the key feature of moderate prechlorination, which can be applied in improving the algae removal of KMnO4Fe(II) process.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Jing
J
Qi
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: hclan@rcees.ac.cn.
Huachun
H
Lan
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Huijuan
H
Liu
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Ruiping
R
Liu
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Shiyu
S
Miao
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Jiuhui
J
Qu
D000327:Adsorption; D002713:Chlorine; D005374:Filtration; D046931:Microcystis
D002713:Chlorine
Cell integrity; KMnO(4)–Fe(II) process; Microcystis aeruginosa removal; Moderate prechlorination; Surface-adsorbed organic matter