TiO2 and ZnO photocatalytic treatment of palm oil mill effluent (POME) and feasibility of renewable energy generation: A short review

The flourishing of palm oil industry in Malaysia is always shadowed by the massive palm oil mill effluent (POME) produced along the oil-extraction process. Without a proper treatment, this POME generated might impose a disastrous destruction to the environment by contaminating water resources. Currently, the open ponding system is widely employed to degrade POME in Malaysia. However, this remediation can hardly cope with hurdle set by the Department of Environmental nowadays due to the growing of the environmental awareness. Therefore, there are strong urges demanding for a new alternative that can effectively treat the POME waste, or even better converting it into renewable energy resources along the treating process. This review provides insights into the feasibility of photocatalytic process for co-treatment of POME for the renewable energy production. Besides, the efficiency and versatility of proposed photocatalysts, TiO2 and ZnO, were also outlined in the current review. This review would serve as an important remark for future studies for not only POME treatment, but also the organic wastewater treatment from the industrials. (C) 2019 Elsevier Ltd. All rights reserved.