Removal of Hexavalent Chromium Cr (VI) From an Aqueous Solution by an Industrial Waste from the Steelworks of the Algerian Steel Complex

Abstract

Algeria has developed a dense Industrial network, concentrating polluting and water and energy consuming sectors. Slag, a waste product of the SIDER steel complex (Annaba, Algeria), was used as an adsorbent for the removal of hexavalent chromium from artificially contaminated aqueous solutions. The experiments were carried out in static regime. The determined best parameters influencing the adsorption such as mass of adsorbant, initial concentration, stirring speed, temperature, and pH, which allowed to reach a significant efficiency rate equal to 99% were as follow: Cr(VI) concentration of 10 ppm, pH 1, contact time at equilibrium 30 min and a temperature of 40°C. Modeling of the experimental data showed that the pseudo-second order model describes the adsorption kinetics in an adequate way. Also, the adsorption isotherms are in agreement with the Freundlich model. Furthermore, the thermodynamic analysis revealed that the studied adsorption process is a favorable, endothermic, and spontaneous phenomenon.