1. Interdisciplinary Graduate School; Nanyang Technological University; Singapore 637141 Singapore
2. Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute; Nanyang Technological University; Singapore 637141 Singapore
3. United Envirotech Ltd; Singapore 117684 Singapore
4. Department of Chemical Engineering; Imperial College London; Exhibition Road London SW7 2AZ UK
5. School of Civil and Environmental Engineering; Nanyang Technological University; Singapore 639798 Singapore