Adsorption behavior of Lanthanum(III) on SQD-85 resin

The adsorption and desorption behaviors of La(III) on SQD-85 resin were investigated using batch and column methods. Batch adsorption studies were carried out with different pH, contact time, and temperature. In the batch system, the SQD-85 resin exhibited the highest La(III) uptake as 478 mg/g at 308 K, at an initial pH value of 6.5. The adsorption of La(III) follows the Langmuir isotherm better than Freundlich isotherm. The thermodynamic parameters such as the positive value of ∆H showed that the adsorption was endothermic in nature and ∆G, which were all negative, indicated that the adsorption of La(III) ions onto SQD-85 resin was spontaneous. Column adsorption experiments indicated the maximum adsorption capacity of 481 mg/g for La(III), and Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. The desorption rate of La(III) was 99.8% when the elution agent is 1.0 mol/L HCl solution. These results suggest that La(III) in aqueous solution can be removed and recovered by SQD-85 resin efficiently.