Possible applications of coal fly ash in wastewater treatment.

Management of coal fly ash as a particulate byproduct of coal burning has become an issue to be solved right away due to environmental concerns related to soil, water, and air pollution. Many attempts have been made by researchers for the conversion of coal fly ash into useful products while searching feasible avenues for its sustainable utilization. Wastewater remediation using coal fly ash is one such attempt solving both waste management and water quality issues. The characteristics like morphology, surface area, porosity, and chemical composition (silica, alumina, iron oxide, titania, etc.) make coal fly ash amenable material for potential application in wastewater treatment. Few reports have summarized the coal fly ash utilization in wastewater treatment but solely discussed the adsorption. Besides adsorption, the current paper aims to highlight the possibilities of using coal fly ash in wastewater treatment by different technologies that extend the utilization scope in the domains of filtration, Fenton process, photocatalysis, and coagulation. The promising use of coal fly ash as an adsorbent, membrane filter, Fenton catalyst, photocatalyst, and as an integral part of these structures is reviewed. Finally, the current trends and future prospects on utilization modes of coal fly ash in wastewater treatment are stated.