1. Department of Environmental Engineering, Faculty of Civil Engineering; Universiti Teknologi Malaysia, UTM; Skudai Johor 81310 Malaysia
2. Centre for Environmental Sustainability and Water Security, Research Institute for Sustainable Environment; Universiti Teknologi Malaysia, UTM; Skudai Johor 81310 Malaysia
3. Department of Environmental Engineering, Faculty of Engineering and Science; Curtin University; Miri Sarawak CDT 250 Malaysia