Abstract
The world today is in a constant quest of generating clean energy which would considerably reduce the emission of greenhouse gas (GHG) for better living conditions. In this study, a comparative analysis between anaerobic mono-digestion and anaerobic co-digestion of food waste (FW) was conducted based on the following parameters; pH, carbon to nitrogen (C/N) ratio, total solids (TS) and volatile solids (VS) content. For anaerobic monodigestion FW alone was used as the substrate while for anaerobic co-digestion, two mixing ratios of FW with cow dung were used (2:1 and 1:2 respectively). Three digesters of 500 ml were used and placed into a water bath at 45°C through a Biochemical Methane Potential (BMP) Test using the Automatic Methane Potential Test System II (AMPTS II). The anaerobic mono-digestion of FW yielded 405.1 Nml of biomethane while the anaerobic co-digestion of FW with cow dung yielded 267.4 and 274.8 Nml at 2:1 and 1:2 mixing ratios correspondingly. The anaerobic co-digestion showed a significant decrease in the specific biogas production by 32.16 to 33.99% in comparison to anaerobic monodigestion. It was observed that the pH (7.21), C/N (31.41), TS (14.64%) and VS/TS (94.4%) of anaerobic mono-digestion of FW fell approximately and within their respective optimum range, 6.5 – 7.5, 15 – 30, 15 – 20% and 82.4 – 95.3%. Hence, it produced the best biomethane yield. The objective of this study was to prove that anaerobic co-digestion of FW with cow dung would produce an improved biogas yield as compared to anaerobic monodigestion.