Palm oil mill effluent (POME) is abundantly generated from the palm oil milling process. Its stringent discharge limits of biological oxygen demand (BOD) of < 20 mg litre-1 has been the most prevalent issue faced in the course of extending palm oil business development. Conventional POME treatment system anaerobically in a series of ponding systems, topped with additional costly tertiary polishing system may not be able to meet this challenging standard due to inconsistent plant performance. A cost-effective POME treatment technology featuring full resource recovery and zero discharge/zero emissions is encouraged. This article examined the performance of an integrated anaerobic-aerobic zero discharge POME treatment pilot system in full operation for a year in a palm oil mill. The assessed system showed 100% compliance to BOD of 100 mg litre-1 and 80% for the more stringent BOD 20 mg litre-1 while generating renewable electricity from the combusted biogas and recycling boiler-grade water via reclamation.

Keywords: anaerobic-aerobic, biogas, biological oxygen demand, palm oil, wastewater