1. School of Environmental and Biological Science and Technology, Dalian Univ. of Technology, Dalian 116024, China; and, Institute of Environmental Science and Engineering, Nanyang Technological Univ., Innovation Centre Block 2 Unit 237, 637723, Singapore.
2. Professor, School of Environmental and Biological Science and Technology, Dalian Univ. of Technology, Dalian 116024, China.
3. Associate Scientist, Institute of Environmental Science and Engineering, Nanyang Technological Univ., Innovation Centre Block 2, Unit 237, 637723, Singapore.
4. Director, Institute of Environmental Science and Engineering, Nanyang Technological Univ., Innovation Centre Block 2, Unit 237, 637723, Singapore. E-mail: wongfs@ntu.edu.sg