Removal of Pb(II) using Polyethylenimine-Crosslinked Polyvinyl Chloride Fiber

Abstract

Heavy metals such as Pb(II) are toxic to ecosystems and humans, and removing heavy metals from water has always been a hot issue. Polyvinyl chloride (PVC) is a widely used synthetic polymer, however, the disposal of waste PVC is still challenging. In this study, polyethylenimine-crosslinked PVC fiber (PEI-PVCF) was developed to remove Pb(II) from aqueous solutions, which not only helps to remove heavy metals, but also provides a possible method for the recycling of waste PVC. The FTIR analysis verified that the PEI was successfully crosslinked with PVC. The effect of pH, contact time, and initial concentration on the adsorption of Pb(II) by PEI-PVCF were evaluated. Through the pH effect experiment, pH 6 was determined as the most suitable pH for Pb(II) removal from aqueous solutions. The isotherm experimental data was well explained by Langmuir model and the maximum Pb(II) uptake was evaluated to be 233.3 mg/g. Pseudo-second-order kinetic model well described the adsorption kinetic data of Pb(II) on PEI-PVCF. The adsorption equilibrium was reached within 120 min at all initial concentrations evaluated. Besides, intraparticle diffusion model proved multiple rate-limiting steps involved in Pb(II) adsorption process. As a result, PEI-PVCF can be considered as a promising adsorbent for Pb(II) removal due to its low cost, high adsorption capacity, and short adsorption equilibrium time.