Anaerobic digestion is a technology based on the degradation of organic matter by microorganisms in an anaerobic environment. Anaerobic co-digestion involves mixing two or more methanizable substrates to optimize methane production ratios. This study focuses on the bioenergy recovery of the biodegradable fraction of waste from the Casamance region. It consists of evaluating the quantitative and qualitative production of co-digestion between cashew apple pulp (CAP) and cow dung (CD) at different percentage ratios. Nine experimental devices were set up for the three mixing ratios: 75% cow dung and 25% cashew apple pulp (noted as 75%CD - 25%CAP), 50% cow dung and 50% cashew apple pulp (rated 50%CD - 50%CAP), and 25% cow dung and 75% cashew apple pulp (rated 25%CD - 75%CAP). The experiments lasted 56 days in a water bath at 37°C, with samples in triplicate to guarantee productivity. During the methanization process of these co-productions, the evolution of parameters such as pH, daily and cumulative biogas production kinetics, and the quality of the biogas produced over time were monitored. The cumulative biogas production and the corresponding optimum methane percentages obtained are: 10.585 L of biogas containing 65.37% methane for co-digestion 75%CD - 25%CAP; 7.147 L of biogas containing 61.23% methane for the co-digestion of 50%CD - 50%CAP; and finally, 6.760 L of biogas containing 63.93% methane for the co-digestion of 25%CD - 75%CAP. This research confirms the importance of waste co-digestion for balancing and improving substrate performance to optimize biogas production.

 

Key words: Co-digestion between cashew apple pulp and cow dung, performance at different percentage ratios, pH, daily and cumulative biogas, mesophilic regime.