Study on the adsorption of Pb2+ from aqueous solution by D113-III resin

The adsorption and desorption behaviors of Pb2+ on D113-III resin were investigated with various chemical methods. The influence of operational conditions such as contact time, initial concentration, initial pH of solution, and temperature on the adsorption of Pb2+ has also been examined. The results show that the maximum uptake capacity of Pb2+ is 476.2 mg/g on D113-III resin at 298 K at pH = 4.5 in HAc–NaAc medium. The adsorption of Pb2+ fitted the Langmuir isotherm better than the Freundlich isotherm. And kinetics on the adsorption of Pb2+ has been studied. The apparent activation energy Ea and adsorption rate constant k298 values are 5.22 kJ/mol and 5.82 × 10-5 s-1, respectively. The data of thermodynamic parameters whose ΔS value is 0.255 kJ/mol K and ΔH value is 45.29 kJ/mol indicate the endothermic nature of the adsorption process. And the negative value of ΔG showed that the adsorption of Pb2+ ions onto D113-III resin was spontaneous. The Thomas model was applied to experimental data obtained from column adsorption experiments. Finally, Pb2+ can be eluted by using 0.5 mol/L HCl solution and the resin can be regenerated and reused. And the sorption of Pb2+ on D113-III resin from simulated seawater is studied.