1. Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, P.R. China.
2. Faculty of Environment and Health Education, Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development, Ashanti Mampong, Ghana.
3. Department of Chemistry, Faculty of Sciences, University of Burundi, Bujumbura, Burundi.
4. Department of Theoretical and Applied Biology, KNUST, Kumasi, Ghana.