Authors: Jie Sun Rui Zhang Long Qin Haixiao Zhu Yu Huang Yingang Xue Shuqing An Xianchuan Xie Aimin Li
Publish Date: 2017/01/13
Volume: 24, Issue: 7, Pages: 6715-6723
Abstract
To further treat the reclaimed municipal wastewater and rehabilitate the aquatic ecosystem of polluted urban rivers an 185km fieldscale 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 NH3N 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 GB57492006 The in vitro SOS/umu assay showed 4nitroquinoline1oxide equivalent 4NQOEQ values of reclaimed municipal wastewater of 069 ± 005 μg/L in April and 068 ± 006 μg/L in December respectively indicating the presence of genotoxic compounds The results of 8hydroxy2′deoxyguanosine 8OHdG and hepatic cell apoptosis in zebrafish after a chorionic longterm 21 days in vivo exposure also demonstrated that the reclaimed municipal wastewater caused significant DNA oxidative damage and cytotoxicity After the ecological purification of 185km fieldscale 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 studyWe gratefully acknowledge generous support provided by NSFC 41203062 and 51438008 Jiangsu Nature Science Fund BK20151378 China’s National Key Project of Science and Technology 2012ZX07204001 2015ZX07204007 and the Fundamental Research Funds for the Central Universities 090514380001
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