1. School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China, Tel. ; Fax:
2. Department of Research and Development, Creative Water Technology China, Ltd. Co., Beijing 100102, China
3. International College of Beijing University of Agriculture, Beijing University of Agriculture, Beijing 100022, China
4. School of Environmental and Municipal Engineering, Jilin Jianzhu University, Changchun 130118, China