Characterization of Cr(III) interaction with kaolinite – Effect of the presence of Cr(VI)

In the present study, experiments were performed to characterize the effectiveness of kaolinite in Cr(III) removal from water in the absence and in the presence of Cr(VI). The results of batch experiments, show that the efficiency of Cr(III) removal by kaolinite increases with the increase of pH and temperature in both cases. The effect of the presence of Cr(VI) on the adsorption of Cr(III) by kaolinite depends on the solution pH and on the concentrations of the two ions. Whatever the system, the removal kinetic of Cr(III) is well described by the pseudo-second order model. Spectroscopic analyses reveal that Cr(III) interaction with kaolinite is mainly electrostatic.