The Effect of Natural Water with Cow Dung and Agricultural Waste Ratio on Biogas Production from Anaerobic Co-Digestion

Global warming caused by energy generation from fossil fuel has accelerated the deployment of renewable fuels such as biogas. In this study, batch fermentation (5L) was studied to observe the effect of natural water, cow dung, rice straw and water hyacinth ratio on the biogas and methane production at ambient temperature (31°C), 7.1-7.4 of pH for 52 days. The five types of co-digestion were 2:1:1:1 (digester A), 1:1:1:1 (digester B), 0.5:1:1:1 (digester C), 1:1:1:0 (digester D) and 1:1:0:1 (digester E), respectively. The result showed that the biogas production increased progressively with amount of natural water to raw material. The maximum biogas production and methane concentration was 1650 mL/days and 61.47% was obtained at substrate mixture 2:1:1:1 (digester A), which there are suitable of C:N ratio at 31.1:1. Natural water, cow dung, rice straw and water hyacinth was mixed for biogas production, have been found to improve highest biogas production compared to those of without rice straw and water hyacinth. Therefore, the mixing natural water, cow dung, rice straw and water hyacinth can improve both biogas production and content of methane in biogas.