Enhanced Removal of Iodine from Wastewater in the Presence of Two-Step Sulfo and Amine Functionalized Polyvinylchloride

Abstract The release of nuclear energy and medical wastewater containing the radioactive isotopes iodine ( 129 I and 131 I) into the environment is causing various environmental problems. In this study, a sulfo- and aminated polyvinylchloride (PVC-(SO 3 H)-NH-PАМ) sorption material was synthesised to effectively remove iodine from wastewater. Sulfonation and amination reactions of polyvinyl chloride were carried out under heterogeneous conditions. It was determined that the order of the amination reaction for the sulfocation exchange resin made from polyvinyl chloride is 1.1 and that the reaction activation energy is 70 kJ/mol. Synthesised functional PVC-(SO 3 H)-NH-PАМ sorption material was characterised using FTIR, SEM-EDX, TGA, DSC, and BET and BJH surface analysis to identify its structure, morphology, and physico-chemical properties. In addition, functional PVC-(SO 3 H)-NH-PАМ material was used to remove iodine from aqueous media. A pseudo first, second order model to describe sorption kinetics as well as Langmuir and the Freundlich isotherm models to explain adsorption mechanisms, were used. The Langmuir isotherm and the pseudo-second order kinetic model led to the most consistent results in describing the removal of iodine from solution. In the case of iodine, the maximum adsorption capacity was 705 mg g − 1 . The correlation coefficients R² values are 0.9987 for I 3 – ions, and the concentration change shows that the adsorption process obeys the Langmuir monomolecular adsorption theory (R L is favourable). In addition, the adsorption kinetics followed a pseudo-second-order model (R² > 0.999). The development of functional sorption material offers a sustainable and environmentally friendly method for the effective removal of toxic iodine from medical wastewater.