1. School of Environment, Harbin Institute of Technology, Harbin 150001, P. R. China
2. College of Environment and Ecology, Chongqing University, Chongqing 400045, P. R. China
3. Institute of Sustainability, Energy, and Environment, University of Illinois at Urbana-Champaign, 1101 W. Peabody Drive, Urbana, Illinois 61801, United States
4. Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States