Abstract
Ph.D. (Chemical Engineering)
Harare, the capital city of Zimbabwe and its surrounding urban centres of Chitungwiza, Epworth, Ruwa and Norton are experiencing enormous municipal solid waste management (MSWM) challenges. This study compared the environmental impacts of six developed MSWM options (A1- A6) that could be considered for future implementation in Harare city and its surrounding urban areas to partly contribute to addressing the prevailing MSWM challenges. The MSWM practises currently being practised and their associated impacts together with global developments in MSWM were reviewed and informed the development of the six MSWM options. The MSWM options were assessed for their associated global warming, human health, acidification and eutrophication impact potentials using the Life Cycle Assessment (LCA) methodology to determine the least impactful option or scenario. An analysis of the impact potential contributions of individual MSWM processes or treatment technologies that constituted the six MSWM options was carried out. Further, a comparative assessment of composting and anaerobic digestion (AD) of biodegradable MSW was undertaken. Opportunities and limitations for MSW source separation, suitability of MSW transfer stations, options for decentralised MSWM and barriers to possible implementation of least impactful MSWM option were reviewed. Review findings of the sustainability of MSWM practices currently being practiced and their impacts show that both groundwater and surface water pollution are manifesting from poor MSWM practices negatively impacting freshwater availability resulting in the outbreak of water borne diseases. Six MSWM options or scenarios (A1–A6) for possible implementation in Harare and its surrounding urban areas were developed. MSWM options A1 and A2 considered the landfilling and incineration, respectively, of indiscriminately collected MSW with energy recovery and by product treatment. Source-separated...