Coal fly ash: an emerging material for water remediation

Coal fly ash (CFA) is a byproduct of thermal power plant and collected from flue gases by separator. Composition of CFA depends on the type of coal used and it has both crystalline and amorphous character. It is considered to be an environmental pollutant and used in number of areas. CFA is a useful material and widely used in cement production and as a promising adsorbent for water remediation. CFA used for remediation of wastewater solves problems related to water quality issues and waste management. The physical properties such as porosity, surface area, morphology, and chemical composition (iron oxide, alumina, silica, titania, etc.) make CFA efficient material for wastewater treatment. CFA is also converted to geopolymer, which is used as an adsorbent and photocatalyst. Dye, organic compounds, toxic heavy metal ions, etc. have been removed using CFA and modified CFA adsorbents. Different adsorption efficiencies have been reported for different adsorbate and CFA adsorbents. Numbers of adsorption isotherm and kinetic models have been discussed.