1. Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission, College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, P. R. China
2. School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, P. R. China
3. Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
4. Ecological and Environmental Monitoring Centre, Guangxi Zhuang Autonomous Region, Nanning 530028, P. R. China