Ponding system or land application techniques are widely used at industrial scale to treat palm oil mill effluent (POME) prior to discharge to the environment. POME is considered as one of the major problems that has generated voluminously from the palm oil industries. The main purpose of this article is to organize the scattered available information on various aspects and a wide range of promising current POME treatments including biological microorganisms, physicochemical methods of coagulation, and membrane and thermochemical process. In addition, the integrated system of anaerobic-aerobic bioreactor (IAAB), which has been touted as highly efficient with easy control at acceptable temperature range and shorter treatment time, has potential to be exploited for POME treatment. The main influencing factors for IAAB POME treatment are highlighted as outstanding characteristics for challenges and future prospects.

A bacterial strain, identified as Lysinibacillus sp. LC 556247 POME, was isolated from palm oil mill effluent (POME). The present article highlights the potential utilization of POME as a sole fermentation medium by Lysinibacillus sp. LC 556247 to produce biomass fuel via aerobic fermentation. The fermentation was performed in a shake flask with a working volume of 300 mL, agitated at 180 rpm, incubated at 35 ± 2 °C for various fermentation hours, ranging from 1, 2, 3, 4, 24, 48, 72, 96, and 120 h, and was followed by a drying process. Elucidation of the POME characteristics, calorific energy values (CEV), moisture content (MC), oil and grease content, chemical oxygen demand (COD), biochemical oxygen demand (BOD), dissolved oxygen (DO), total suspended solids (TSS), pH, total nitrogen, and the colony-forming unit (CFU) were performed. The results demonstrate that the highest CEV, of 21.25 ± 0.19 MJ/kg, was obtained at 48 h fermentation. High amounts of extractable oil and nitrogen content were retrieved at the highest CEV reading of the fermented and dried POME samples, which were 17.95 ± 0.02% and 12.80 ± 0.08%, respectively. The maximum removal efficiencies for the COD (50.83%), the BOD (71.73%), and the TSS (42.99%) were achieved at 120 h of fermentation, with an operating pH ranging from 4.49–4.54. The XRF analysis reveals that the fermented and dried products consisted of elements that had a high amount of carbon and potassium, and a significantly low amount of silica, which is sufficient for the effective burning of biomass fuel in the boiler.