1. School of Environmental Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
2. Wetsus, Centre of Excellence for Sustainable Water Technology, P.O. Box 1113, 8900CC Leeuwarden, The Netherlands
3. Department of Environmental Technology, Wageningen University and Research, P.O. Box 17, 6700AA Wageningen, The Netherlands