1. Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, 2628 CN Delft, The Netherlands
2. Faculty of Earth Science, Universiti Malaysia Kelantan, UMK Kampus Jeli, 17600 Jeli, Kelantan, Malaysia
3. Nalco Europe BV, Ir. G. Tjalmaweg 1, 2342 BV Oegstgeest, The Netherlands