The elimination by natural algerian clay of chromium ions from salt water

Abstract

This paper studies the removal of chromium ions from synthetic brackish water by an adsorption method using natural Algerian Bentonite (NAB), the mineral clay was characterized through FTIR, XRD and SEM/EDS analysis. The effect of the main physicochemical parameters; namely: Clay dosage, initial metal ion concentration, pH, and contact time on the removal of Cr+3 was investigated. The results showed that equilibrium was attained within 5 minutes of stirring time. The retention capacity of Cr+3 increased with the increase of adsorbent dose and decreased with the increased initial metal ion concentration. The Langmuir and Freundlich isotherm models were applied to determine the efficiency of bentonite used as an adsorbent. According to the obtained results, the Langmuir model adjusts very well to the experimental data. Based on the kinetic studies for the raw bentonite, it was verified that the mechanism corresponds to predominant pseudo-second- order adsorption.