Enhancing biogas yield and compositions from solid waste using leaves of different plants as phytocatalysts

Biogas offers eco-friendly approach for waste management. Herein, enhancing biogas production from cow dung using leaves of different plants: turmeric, neem and papaya was investigated under anaerobic conditions over 30 days retention time with daily measurements of biogas yield (kg) and compositional analysis using gas chromatographic thermal donductivity Detector (GC-TCD) in the different bioreactors set up designated as cow dung with turmeric powder (CDTP), cow dung with neem powder (CDNP), cow dung with papaya powder (CDPP) and cow dung without any powder served as control (CTRL). As digestion ended by day 30, CDNP had the highest biogas yield (0.63 ± 0.03), followed by CDPP (0.29 ± 0.09), then CDTP (0.25 ± 0.06) while CTRL had the least yield (0.17 ± 0.03) and the various yields obtained were significantly different (p<0.05) from one another. Similarly, CDNP still showed the highest CH4 concentration (77.256%), followed by CDPP (74.416%) and CDTP (70.792%) while CTRL had the lowest (64.964%). However, CO₂ compositions were inversely proportional to methane, with CTRL showing the highest (27.029%) and CDPP the lowest (21.490%). Trace gases (NH₃, CO, H₂S) were minimal but varied significantly among treatments. Thus, the leaf powders particularly neem effectively enhanced biogas yield and methane content.