1. Water and Environmental Engineering, Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
2. Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
3. Centre for Technology in Water and Wastewater, University of Technology, Ultimo, Sydney, NSW 2007, Australia
4. Division of Advanced Membrane Science and Technology, Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Kobe 657-8501, Japan