Applications of Fenton oxidation processes for decontamination of palm oil mill effluent: A review

Abstract

Oil palm agro-industry is a major revenue earner for Malaysia with the country being one of the major producers of crude palm oil (CPO) and oil palm products. Its growth has, however, led to massive water consumption and high generation of highly polluting palm oil mill effluent (POME). The inadequacies of ponding system adopted by most palm oil mills (POMs) for the treatment of POME to alleviate environmental and public health concerns are quite alarming. Fenton advanced oxidation technologies are a current research area providing viable alternatives for POME treatment, recovery and managing high demand for water. Its major setback is the generation of a large amount of unwanted sludge of iron (III) complexes thus increasing the costs of sludge management, treatment, and disposal. The salient and promising features of this technique for industrial applications motivate researchers to find ways to overcome its inherent drawbacks. This brief review aimed at discussing and evaluating the performances of the various Fenton oxidation processes, including homogeneous, heterogeneous, photo-Fenton, electro-Fenton, sono-Fenton etc., for POME treatment. Discussions on the future direction of these Fenton processes points towards the utilization of abundant magnetically separable heterogeneous composites as catalysts with high stability, activity, recyclability, and cost-effectiveness for decontamination of POME and other agro-industrial effluents from recalcitrant organic pollutants. The low deployment of such composite catalyst coupled with scarce literature on POME treatment in this regard offers a vast opportunity for research exploration.

Keywords

• Agro-industrial effluent
• Fenton oxidation
• Heterogeneous catalyst
• Homogenous catalyst
• Palm oil mill effluent
• Water pollution