title: Genotoxicity and cytotoxicity reduction of the polluted urban river after ecological restoration: a field-scale study of Jialu River in northern China.
abstract: To further treat the reclaimed municipal wastewater and rehabilitate the aquatic ecosystem of polluted urban rivers, an 18.5-km field-scale ecological restoration project was constructed along Jialu River, a polluted urban river which receives only reclaimed municipal wastewater from Zhengzhou City without natural upland water dilution. This study investigated the potential efficiency of water quality improvement, as well as genotoxicity and cytotoxicity reduction along the ecological restoration project of this polluted urban river. Results showed that the chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) of the reclaimed municipal effluent were reduced by more than 45 and 70%, respectively, meeting the Chinese surface water environmental quality standard level IV, while the total phosphorus and metal concentrations had no significant reduction along the restoration project, and Pb concentrations in all river water samples exceeded permissible limit in drinking water set by WHO (2006) and China (GB5749-2006). The in vitro SOS/umu assay showed 4-nitroquinoline-1-oxide equivalent (4-NQO-EQ) values of reclaimed municipal wastewater of 0.69 ± 0.05 μg/L in April and 0.68 ± 0.06 μg/L in December, respectively, indicating the presence of genotoxic compounds. The results of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hepatic cell apoptosis in zebrafish after a chorionic long-term (21 days) in vivo exposure also demonstrated that the reclaimed municipal wastewater caused significant DNA oxidative damage and cytotoxicity. After the ecological purification of 18.5-km field-scale restoration project, the genotoxicity assessed by in vitro assay was negligible, while the DNA oxidative damage and cytotoxicity in exposed fish were still significantly elevated. The mechanisms of DNA oxidative damage and cytotoxicity caused by the reclaimed municipal wastewater need further study.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan, Shandong, 250022, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Long
authors.initials: L
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Haixiao
authors.initials: H
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.|Changzhou Environmental Monitoring Center, Changzhou, Jiangsu, People's Republic of China.
authors.forename: Yingang
authors.initials: Y
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Shuqing
authors.initials: S
authors.lastname: An
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China. xchxie@nju.edu.cn.
authors.forename: Xianchuan
authors.initials: X
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, School of Life Science, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
mesh_terms: D000641:Ammonia / Q000032:analysis; D000818:Animals; D057919:Biological Oxygen Demand Analysis; D002681:China; D002947:Cities; D004249:DNA Damage; D017753:Ecosystem; D052918:Environmental Restoration and Remediation; D005399:Fishes; D008099:Liver / Q000187:drug effects; D009152:Mutagenicity Tests; D045483:Rivers; D012486:Salmonella typhimurium / Q000235:genetics; D062065:Wastewater / Q000032:analysis / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification; D060753:Water Quality; D015027:Zebrafish / Q000235:genetics
chemical_list: D000641:Ammonia; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: 8-OHdG; Cytotoxicity; Ecological restoration; Genotoxicity; Reclaimed wastewater; Urban river