1. School of Environmental Science and Engineering, Southern University of Science and Technology, 1088 Xueyuan Blvd, Nanshan District, Shenzhen 518055, P. R. China
2. Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong SAR 999077, P. R. China
3. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
4. Faculty of Science and Technology, Technological and Higher Education Institute of Hong Kong, Hong Kong 999077, China