Use of gel-type weak acid resin for the adsorption of La(III) from aqueous solution

摘要

The adsorption properties of a gel-type weak acid resin (110-H) for La(III) have been studied with chemical methods. The effects of process variables, such as initial pH of solution, initial concentration of La(III), contact time and temperature, on the adsorption of La(III)) have been studied using batch technique. The results show that the optimal adsorption condition of GTWAR for La(III) is achieved atpH 5.0 in HAc-NaAc medium. The maximum uptake capacity of La(III) is found to be 263 mg/g resin at 298 K. The adsorption of La(III) follows the Langmuir isotherm better than Freundlich isotherm, and the correlation coefficients have been evaluated. Even kinetics on the adsorption of La(III) has been studied. The thermodynamic parameters ΔS 121 J/(mol-K) and ΔH 16.4kJ/mol indicate the endothermic nature of the adsorption process. A decrease in Gibb's free energy with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, La(III) can be eluted by using 0.5mol/L HCl solution and the gel-type weak acid resin can be regenerated and reused. The sample is evaluated by IR spectroscopy and thermogravimetric analysis.