1. School of Materials, Energy, Water, and Environmental Sciences (MEWES), The Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Arusha, Tanzania
2. Department of Science Education, School of Science, Mathematics, and Technology Education (SoSMTE), C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Postal Box 24, Navrongo, Upper East Region, Ghana
3. Department of Chemical Engineering, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, P. O. Box 17011, Doornfontein 2028, South Africa