1. Researcher, Water and Environment Centre, Sana’a Univ., Sana’a, Yemen; Ph.D. Fellow, Environmental Engineering and Water Technology, IHE-Delft Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands (corresponding author).
2. Associate Professor, Water Supply Engineering, IHE-Delft Institute for Water Education, Delft, The Netherlands.
3. Professor, Water Treatment and Technology, IHE-Delft Institute for Water Education, Delft, The Netherlands.