Conversion of palm oil mill effluent on biogas production with consortium bacteria

Abstract

Palm Oil Mill Effluent (POME) is a liquid waste that has a high organic content and it can be fermented using bacteria to produce biogas. POME is non-toxic but the high organic contents can disturb the ecosystems and cause the environmental pollution in the water body. POME contains microorganisms that have the potential to hydrolyze oils, celluloses, and protein. Potential bacteria for degradation of POME can be obtained by isolating the waste itself (indigenous bacteria). Indigenous bacteria that have been isolated from POME, namely: Stenotrophomonas rhizopila strain E-P10 (KP 1.2) and Bacillus toyonensis strain BCT-7112 (KAN 1) are used as consortium bacteria in the process of waste degradation. The research sequence consists of rejuvenation of bacteria, preparation of medium mineral, starter and bacterial inoculum. The research aims to degrade the substrates from POME using a consortium and indigenous bacteria to produce biogas. The substrate degradation process is carried out in a bioreactor with degradation time 0, 20, 21-22, 23-26, 27-30, 31-34 and 35-38 days. Bacterial population growth was calculated using a haemacytometer. The highest population of the consortium and indigenous bacteria were found at 7.94x107 mg/mL and 7.23x107 mg/mL. The biogas contents were analyzed using the Gas Chromatography (GC) with units of % mole. The highest production of biogas contains 68.6 % mole methane gas (CH4) and 21.7 % mole carbon dioxide gas (CO2) with the consortium bacteria. While using the KAN 1 bacteria, the highest production of biogas contains 64.0 % mole methane gas (CH4) and 22.0 % mole carbon dioxide gas (CO2).