Adsorption behavior of calcined layered double hydroxides towards removal of iodide contaminants

Calcined layered double hydroxide (CLDH) as a potential adsorbent to remove iodide contaminants was investigated in batch mode. The uptake capacity of calcined LDH is higher than that of LDHs as precursor, due to their different mechanism which is supported by XRD and TG-MS measurements. The influences of CLDH structure, dosage of CLDH, initial concentration of iodide ion and co-existing anions on the removal of iodide ion have been investigated. The applicability of the Langmuir isotherm shows that the maximum uptake capacity was approximately 376 mg/g, and Gibbs free energy (AGO) for the process is -23.8 kJ/mol. The negative AGO value shows the spontaneity of the adsorption process.