[1] Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon,999077, Hong Kong
[2] School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou,510275, China
[3] Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou,510275, China
[4] Hong Kong Br. of Chinese Natl. Eng. Res. Center for Control and Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon,999077, Hong Kong