1. College of Environmental Science and Engineering; Hunan University; Key Laboratory of Environmental Biology and Pollution Control (Hunan University); Ministry of Education; Lushan South Road Changsha 410082 P. R. China
2. Department of Chemistry; University of Science and Technology of China; Hefei 230026 China
3. Research Center of Environmental Science and Engineering; Center South University of Forestry and Technology; Shaoshan South Road Changsha 410004 China