Novel negatively charged hybrids. 3. Removal of Pb2+ from aqueous solution using zwitterionic hybrid polymers as adsorbent

Using zwitterionic hybrid polymers as adsorbent, the adsorption kinetics and isotherm, thermodynamic parameters of ΔG, ΔH and ΔS for the removal of Pb2+ from aqueous solution were investigated. It is indicated that the adsorption of Pb2+ ions on these zwitterionic hybrid polymers followed the Lagergren second-order kinetic model and Freundlich isotherm model, demonstrating that the adsorption process might be Langmuir monolayer adsorption. The negative values of ΔG and the positive values of ΔH evidence that Pb2+ adsorption on these zwitterionic hybrid polymers is spontaneous and endothermic process in nature. Moreover, the zwitterionic hybrid polymers produced reveal relatively higher desorption efficiency in 2 mol dm−3 aqueous HNO3 solution, indicating that they can be recycled in industrial processes. These findings suggest that these zwitterionic hybrid polymers are the promising adsorbents for Pb2+ removal and can be potentially applied in the separation and recovery of Pb2+ ions from the waste chemicals and contaminated water of lead-acid rechargeable battery.