Green Synthesis of Silica Nanoparticles (Si-NPs) from Palm Oil Fuel Ash (POFA) and its Application to Purification Water: A Review

Abstract

Abstract Increasing the volume of palm oil production impacts the amount of waste the palm oil industry produces. This waste, if handled properly, will have a positive impact on the environment. Boiler efficiency and energy value can be increased while reducing solid waste and fossil fuel emissions by using shells and fibres as fuel. However, burning biomass as boiler fuel leaves residue as palm oil fuel ash (POFA) and is generally thrown away. POFA contains silica and can be extracted and synthesized into silica nanoparticles (Si-NPs) by process engineering. Si-NPs derived from agricultural waste or renewable sources are environmentally friendly and have unique properties such as high surface area, adjustable pore diameter, and excellent chemical and thermal stability. These properties make Si-NPs ideal for water purification, and this paper reviews recent advances in the synthesis of Si-NPs using POFA, future research directions, and challenges in the application of Si-NPs for water purification. This review compiles information from research articles on the current synthesis of environmentally friendly Si-NPs as study material to develop and utilize POFA waste as a biomaterial in fabricating filtration membranes in water purification.