Removal of cadmium from industrial wastewater by steel slag

The steel slag is the main by-product of steel industry. The aim of this study using the steel slag as a low-cost absorbent in order to remove cadmium pollutant from industrial wastewater. Methods and Materials: Some factors that affect the process of cadmium removal by steel slag such as PH, contact time, absorbent dosage and cadmium initial concentration has been studied. Standard solution of synthetic wastewater including cadmium has been prepared by adding Chloride Cadmium to distilled water and concentrations in the range of 5-25 mg/l have been reached. The results show that in optimum conditions, the removal of cadmium from aqueous solution with concentration about 25mg/l and 60min contact time is about 99%. The experimental data of adsorption equilibrium have been analyzed according to adsorption kinetics models and Freundlich and Langmiur adsorption isotherms. The physical, chemical and morphological features of the steel slag have been determined by XRD, XRF and SEM techniques, too. The result of the experiments determined that the steel slag could be used as an effective and low-cost method in removing cadmium from industrial wastewater.