Optimisation of copper and zinc ions removal from aqueous solution by coal fly ash as an adsorbent

Abstract

Rapid urbanization and industrialization of our world has led to accumulation of enormous number of contaminants in our environment. Heavy metal ions hold a superlative position in that list and are responsible for contaminating soil, air and water in many parts of the world. Adsorption technology is emerging as a sustainable effective solution. The possibility of using Coal fly ash as an alternative adsorbent for divalent metal ions (Zn2+, Cu2+) removal from simulated solutions was studied. The coal fly ash was characterised by Brunauer Emmet Teller (BET), X-ray diffraction (XRD), X-ray Fluorescence Spectroscopy (XRF) and Fourier transform infrared (FT-IR). Optimum adsorption conditions were determined as a function of pH, adsorbent dosage and contact time for Zn2+ and Cu2+ removal. The adsorption of metal ions was found to be pH dependant. Equilibrium data fitted well to the Freundlich model with R2 values as 0.9932, 0.9971 for Cu2+, Zn2+, respectively. The study showed that disposed coal fly ash could be used as an efficient adsorbent material for the removal of metal ions from aqueous solution.