Conventional and advanced treatment technologies for palm oil mill effluents: a systematic literature review

Palm oil mill effluent (POME) contains high amount of organic contents and residual oil associated with many environmental concerns related due to discharge of untreated POME. POME is a highly polluting effluent that demands appropriate handling before it can be disposed to the water bodies. POME treatment is a significant concern in palm oil mills and the treatment technique has fascinated several researchers related with environmental pollution. Numerous conventional treatment approaches are unsuccessful to accomplish the standard needed to reduce the pollutants in the POME to allowable levels. Several advanced treatment technologies have developed with high productivity to lessen the contaminants levels. However, the incorporation of conventional treatment with advanced technologies is a feasible tactic for POME treatment. Therefore, in the current review, systematic literature review (SLR) was conducted to organize the scattered available information and provides insight on the various treatment methods of POME. From the SLR, it is evident that advanced oxidation process, membrane bioreactors, and adsorption is a feasible way, hence, resolving the environmental issues of waste disposal and pollution arising from the palm oil industry.