1. Department of Civil Engineering, Kwara State University, P.M.B. 1530 , Malete, Kwara State, Nigeria
2. School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Wits, Johannesburg, 2050, South Africa
3. UNESCO-IHE Institute for Water Education, P.O. Box, 3015 DA Delft, 2601, The Netherlands