Abstract:
he production of biogas through anaerobic digestion of organic waste materials offers an
environmentally friendly and renewable energy alternative. Evaluate biogas production from
sugarcane leaves (SL) and sheep manure (SM) using anaerobic digestion at five treatments:
100% SL, 100% SM, 60:40% SL to SM, 60:40% SM to SL, and a 50:50 SL to SM mix. This was
evaluated under mesophilic conditions (38ºC) using a batch digester in the Botanical Laboratory
of Haramaya University over a period of 29 days. In all treatments, parameters such as total
solids (TS), volatile solids (VS), organic carbon, pH, and nitrogen were measured before and
after digestion, while the carbon-to-nitrogen (C/N) ratio was measured only before anaerobic
digestion. The results indicated that the highest pH value (7.18) was observed in the 100% SM
treatment, while the lowest pH value (6.61) was recorded in the 100% SL treatment before
anaerobic digestion. Comparisons of pH values before and after anaerobic digestion showed a
significant increase in pH across all treatments. Additionally, the highest values for TS and VS
were recorded in the 100% SM treatment. The C/N ratios were also analyzed, revealing that the
highest ratio was in the 100% SL treatment, while the lowest was in the 40% SM + 60% SL mix.
Biogas production was measured in all treatments from the first day of digestion, eventually
declining to zero after about 29 days of incubation in all treatments. All measured
physicochemical parameters of each substrate showed significant variations between the before
and after AD measurements, with the rate of variation differing between substrates. The
maximum cumulative biogas production (2073 ml) was recorded in the 60% SL and 40% SM
mix, while the minimum (1102 ml) was observed in the 100% SM treatment, suggesting that the
60% SL and 40% SM mix is the optimal combination for higher biogas yield. The study results
demonstrated that co-digested substrates of the three mix ratios produced a higher amount of
biogas compared to the individual substrates alone
