Value Recovery of Septage Through Compost Production from Septage and Household Waste: Case of the Urban Municipality of Mamou, Guinea

The management of septic sludge and household waste is a major challenge for cities in Guinea in general, and for the urban commune of Mamou in particular. The sanitation sector is very poorly structured, characterized by the predominance of independent facilities and the absence of regulation for emptying services. This study aims to carry out a trial for the valorization of these types of waste produced in the urban commune of Mamou. The methodology consisted of collecting the substrates (septic sludge and household waste). Then, a sampling of 34 kg of each type of waste was done for co-composting. The substrate composting process lasted 40 days; the quantities of compost produced were evaluated. The different substrates produced respectively 23.3 kg of compost for concentrated septic sludge, or 68.52%, with 10.7 kg of residue, or 31.47%. The household waste substrates produced 22.65 kg of compost, or 66.62%; with a amount of residue of 11.35 kg, or 33.38%. Co-composting (septic sludge with household waste) produced 28.69 kg of compost, or 84.38%, with a residue amount of 5.31 kg, or 15.61%. The curves showing the variation in composting temperature for the three types of substrates (septic sludge, household waste, and septic sludge + household waste) each display three phases (initial, short thermophilic, and stabilization). The results obtained show that co-composting the substrates is the most suitable method for valorizing septic sludge in the context of sustainable organic waste management in Mamou.