Characterization and Valuation of the Domestic Solid Waste of Fidjrosse District in Cotonou (Republic of Benin) by Aerobic Composting

This work proceeded in Fidjrosse district in Cotonou from November 2009 to December 2010. It consisted with a field investigation, with the characterization of the urban solid waste collected in this district, with valorisation by aerobic composting of the fermentable fraction of the waste. From work of investigation it arises that 25 % of households continue to throw their faeces on wild dumps while 13.33 % continue to make the incineration. 81. 67% of the surveyed households have a daily production of waste lower than 1 kg. The characterization of collected waste records in mass 50.19% of biodegradable matters; fine sand 32.18%; 0.63% of shells, carapaces of crabs and pearls; 0.13% of engraved and pieces of brick; 8.31% of plastics; 4% of paperboard; 1.58% of metal; 1.11% of textile and debris of mattress; 1.01% of glasses; 0.79 of shoes and leathers; 0.7% of used batteries; 75% of moisture for the fermentable fraction. On the whole, 262kg of fermentable waste was composted with an output of 65, 67% which is approximately 172kg of ripe compost. The physico-chemical characteristics of the compost obtained give inter alia values a report of ratio C/N of 11.69% and one rate of total phosphorus 0.062%. The real-mould of our compost has a heavy CEC and holds the nutritive mineral ions as the cations K⁺ and Ca²⁺ and phosphate so as to make available for plants for their growth and to improve the soil fertility of the site as well as its increased need for organic soil conditioner.