Investigation on effect of pH level of substrate by lime water and acetic acid treatment on biogas production through anaerobic digestion

The lime-utilizing industries needed alternative technology to reduce the cost of wastewater treatment. In this context, biogas has the potential to increase energy access in industries while simultaneously reducing dependency on fossil fuels. Hence, this study was to determine the suitability of lime water for the preparation of inoculum for the anaerobic digestion process to produce biogas. In addition to being used for industrial purposes, biogas can be converted into energy for use in the home for cooking and heating. The results showed that for various mixing ratios, biogas production ranged from 2669.81 to 4788.61 and methane content ranged from 58.34 to 61.08% and the gas chromatography showed almost same values of 56.8–60.97%. First-order kinetics statistical analysis and the modified Gompertz model yield R2 values of 0.986 to 0.992 and 0.988 to 0.996, respectively. That importance can be shown in the correlation studies for the various mixing ratios at the 0.01 and 0.05 levels. The VFA to alkalinity ratio for all ratios in the digestate analysis was found to range from 0.18 to 0.47, showing that the digesters are operating under stable conditions.