1. Dep. of Soil Pollution Control; Chinese Research Academy of Environ. Sci.; Dayangfang 8 Beijing 100012 P.R. China
2. School of Chemical Eng. and the Environ., Beijing Institute of Technology; Beijing 100081 P.R. China
3. College of Civil and Environmental Eng., Univ. of Science & Technology Beijing; Beijing 100083 P.R. China
4. Institute of Water Sciences, Beijing Normal Univ.; Xinjiekou Wai Street 19 Beijing 100875 P.R. China