Removal of cadmium (II) from aqueous solution using pure smectite and Lewatite S 100: the effect of time and metal concentration

The possibility to reduce the levels of cadmium (II) from aqueous solutions using pure clay and Lewatite S 100 ion exchange resin has been investigated in this study. The smectite was characterized and the cation exchange capacity (CEC) was measured using usual analytical methods. The effects of parameters such as metal concentration, resin contact time on the ion exchange separation have been studied. Lewatite S 100 shows a remarkable increase in sorption capacity for Cd(II). The batch ion-exchange process was relatively fast; and it reached equilibrium after about 120 min of contact for resin and 6 h for pure smectite. The concentrations of metal ions have been measured by batch techniques and with AAS analysis. Adsorption analysis results obtained showed that the adsorption pattern on the resin followed Langmuir isotherms.