Structural Modification of a Lamellar Solid by Thermal Treatment. Effect on the Cd and Pb Adsorptions from Aqueous Solution

The clay minerals, lamellar solids of aluminum silicate hydrate of layer structure, present physical and chemical properties that are attractive for applications in different industries. These materials represent a promising option to achieve retention of certain contaminants present in the aqueous solution, due to their natural ability for adsorption. Heavy metals such as lead, cadmium, mercury, cooper and zinc, etc., contained in effluents produced by various anthropogenic activities constitute an important phase of pollution. Adverse effects on the health of the population because of the deteriorating quality of watercourses require reversing the current situation. This study evaluates the adsorption of lead and cadmium in aqueous solution by a bentonite, a rock composed majorly by clay minerals of the smectite group. The adsorption capacity was analyzed in the natural condition of the bentonite and after thermal treatment up to 750¼C.