1. Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang Selangor, Malaysia
2. Radiation Processing Technology Division (BTS), Malaysian Nuclear Agency, Bangi, 43000 Kajang Selangor, Malaysia
3. Prince Khalid Bin Sultan Chair for Water Research Centre, College of Engineering, King Saud University, P. O. Box 800, Riyadh 11421, Saudi Arabia