Palm Oil Industries in Malaysia and Possible Treatment Technologies for Palm Oil Mill Effluent: A Review

Palm oil industries have become the main sector to boost the economic revenue in tropical countries, especially in South East Asia. In the recent years, the global production of palm oil reached 72 million metric tons in 2018, increasing from about 68 million metric tons in 2017. During that period, Malaysia is currently the second world producer of palm oil after neighbouring country Indonesia. Both countries are the leading exporters of palm oil with 84 % of worldwide production. A detailed analysis of the palm oil business in Malaysia, the environmental issues that have arisen, and the treatment technology used to effectively treat palm oil mill wastewater are reviewed to gain an understanding of environmental sustainability. In Malaysia, most of the oil palm plantations are owned by private conglomerates (61 %), followed by the independent smallholders (16 %), the Federal Land Development Authority (13 %), state agencies (6 %), the Federal Land Consolidation and Rehabilitation Authority (3 %), and Rubber Industry Smallholders Development Authority (1 %). However, the rate of deforestation has increased due to the expansion of oil palm plantations in Malaysia. Palm oil mill effluent is also considered as one of the major environmental issues since it reduces the water quality index. Some techniques are implemented to treat palm oil mill effluent, such as anaerobic ponding systems, integrated anaerobic-aerobic bioreactors, coagulation and flocculation, thermochemical treatment, vermicomposting, membrane filtration, photocatalysis, moving bed biofilm reactors, and zero liquid discharge. Zero liquid discharge method is considered an appropriate method since this method provides a better waste recovery.