Characterization, quantification and recovery prospects for organic waste from the town of Dolisie in the Republic of Congo

Abstract

Developing countries are facing increasing urbanization accompanied by the production of large quantities of solid household waste, the management of which is a crucial problem. This study aims to characterize, quantify and promote the recovery of organic waste in Dolisie, Republic of Congo. More specifically, it aims to: (i) Determine the flow of solid household waste produced in Dolisie and (ii) Evaluate the physical properties of solid household waste with a view to predicting possible recovery routes for organic waste. Waste from 60 households of different socio-economic levels was collected, weighed, dried and classified daily for 60 days, during the wet (February 15 - May 15, 2021) and dry (July 12 - September 30, 2021) seasons. The results showed that the average daily production of solid household waste in the city of Dolisie was 0.82±0.23kg/capita/day in the wet season and 0.61±0.10kg/capita/day in the dry season. Daily per capita production correlates positively with family income and negatively with household size. The average density of waste produced was 355.71±92.99kg/m3 and 308.02±74.15kg/m3 respectively for the wet and dry seasons. The moisture content of the waste varies between 40-80% in both seasons. The waste stream collected is dominated by waste sizes between 100-20mm. The study revealed that the composition of solid household waste produced in Dolisie is dominated by biodegradable waste, which can be recycled in several sustainable ways: composting, biomass pyrolysis and biogas production.