Simultaneous removal of copper and fluoride from wastewater by adsorption using chicken eggshell

Abstract

In recent years, agricultural wastes and biomass have been extensively investigated as low cost adsorbents in heavy metal removal owing to the facts that they are relatively cheap and exhibit high adsorption capacities. Even though promising results are reported in literature, information on the simultaneous removal of co-existing pollutants is still very scarce and limited. Since industrial effluents contain various pollutants, there is a need to develop biosorbents and system that are able to remove more than one pollutant at one time. In this research, chicken eggshell was investigated for its ability to remove copper and fluoride simultaneously from aqueous solution. The optimization study showed that the highest removal percentage for copper and fluoride could be achieved at the process conditions as such: adsorbent dosage of 2.5 g, temperature of 40°C, pH 6 and stirring speed of 350 rpm. Simulatenous removal of both copper and fluoride ions from mixed solution was possible, however, with a reduction of approximately 26 – 35 % in fluoride removal but insignificant drop in copper removal percentage compared to single pollutant solution. Scanning Electron Microscopy (SEM) analysis revealed deposition of flake-like copper and fluoride crystals on the surface of the chicken eggshell powder thus evidenced its adsorption ability of copper and fluoride ions from aqueous solution.