Production of Energy from Palm Oil Mill Effluent during Start-up of Carrier Anaerobic Baffled Reactor (CABR) Equipped with Polymeric Media

Abstract

Performance of carrier anaerobic baffled reactor (CABR) equipped with polymeric media for energy production and pollution removal from raw palm oil mill effluent (POME) was investigated. Reactor operation was studied in start-up period with no effluent recycled feed and after alkalinity supplementation. Primarily, CABR was fed with diluted POME (COD = 2100 mg/L and OLR = 0.53 g-COD/(L d ) which was then increased gradually to actual concentration (COD = 52,500 mg/L and OLR = 13.13 g-COD/(L d)). The volumetric methane production and methane yield were reached to 2.3 L-CH₄/(L d) and 0.25 L-CH₄/g-COD removed, respectively at the end of start-up period. The biogas was containing 75 - 54 % methane. pH profile and stability of volatile fatty acids (VFA) concentration in CABR effluent indicate that anaerobic system is active in the reactor throughout the study. Use of methanogen-enriched inocula and appropriate separation of acidogens and methanogens in CABR were the reasons for satisfactory performances of the anaerobic system.