Study on Purification Effect of Artificial Wetland on Micro-polluted River Zhao Changheng, Cha Fengjuan, Le Yongzhi, Zhou Guangsheng and Qian Liping E3S Web Conf., 136 (2019) 06023 Published online: 10 December 2019 DOI: 10.1051/e3sconf/201913606023