Chaim Vivien DOTO^1,, Bidossessi Avinou Melhyas KPLE¹, Wilfrid ADIHOU², Maurel AZA-GNANDJI¹, Grâce CHIDIKOFAN², Guevara NONVIHO³, Gontrand Comlan BAGAN¹, Aristide HOUNGAN³, Hyppolite AGADJIHOUEDE¹

Rapid urbanization in sub-Saharan Africa is placing increasing pressure on municipal solid waste management (MSWM) systems, which remain largely fragmented and are often limited to primary waste handling due to institutional, technical, and financial constraints. In many medium-sized cities, the high proportion of organic matter and elevated moisture content further restrict the range of feasible treatment options, thereby challenging the sustainability of conventional composting-based approaches. This study presents a system-oriented technical assessment of MSWM in Abomey-Calavi, one of the fastest-growing cities in southern Benin, and proposes an integrated management framework specifically adapted to local waste characteristics and socio-economic conditions. The analysis draws on validated waste characterization data, field observations, and comparative insights from operational experiences in other West African cities. Municipal solid waste generation in Abomey-Calavi averages approximately 0.89 kg·cap-1·day-1, with a predominance of organic matter (approximately 51%) and a high average moisture content (around 70%). These characteristics significantly constrain direct thermochemical conversion and necessitate the integration of sorting and moisture-reduction stages along the waste management chain. The proposed MSWM framework is structured around three interconnected stages, pre-collection, collection, and treatment, and emphasizes complementary valorization pathways. Composting is maintained for the fermentable fraction but is demonstrated to be insufficient as a standalone solution. Consequently, thermochemical treatments, particularly pyrolysis and controlled combustion, are incorporated to enhance energy recovery and achieve substantial waste volume reduction following appropriate pre-treatment. The framework further integrates decentralized transfer centers and a controlled landfill for the final disposal of residual fractions. The results indicate that combining biological and thermochemical processes within a coordinated institutional and financial structure can significantly improve the technical performance and environmental sustainability of MSWM systems in rapidly urbanizing contexts. Beyond the specific case of Abomey-Calavi, the proposed approach offers a transferable planning framework for cities facing similar constraints across sub-Saharan Africa and other developing regions. The framework is intended as a strategic planning and decision-support tool and does not aim to provide process-level modeling or site-specific techno-economic optimization.

Municipal solid waste management, Waste valorization, Integrated waste management, Composting Pyrolysis, Abomey-Calavi