1. College of Environmental Science and Engineering, Hunan University, Changsha 410082, P.R. China
2. Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, P.R. China
3. Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
4. School of Energy Science and Engineering, Central South University, Changsha 410083, P.R. China
5. College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, P.R. China