High organic loading rate treatment of palm oil mill effluent using a pilot-scale integrated anaerobic-aerobic bioreactor: A comprehensive performance study

Abstract

This study evaluates a pilot-plant Integrated Anaerobic-Aerobic Bioreactor (IAAB) for treating Palm Oil Mill Effluent (POME) at a high Organic Loading Rate (OLR) of 30.0 gCOD/L.day. Conducted over 118 days, the research aimed to optimise operational parameters to meet discharge standards. The system’s effectiveness was measured by its ability to reduce Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS) alongside methane production and process stability. Results showed high removal efficiencies: BOD (99.95 %), COD (99.58 %), and TSS (99.24 %), with a consistent methane yield of 0.218 ± 0.032 LCH₄/gCOD_removed. These outcomes confirm the IAAB’s capability to maintain effluent quality with BOD under 20 mg/L, complying with the Department of Environment (DOE) Malaysia standards without pH adjustment. The study supports the IAAB’s efficiency in handling significant pollutant loads with stable performance and substantial biogas production, presenting it as a viable solution for sustainable energy management in the palm oil industry. Future research will investigate co-digestion processes to enhance methane yield and economic viability.