ABSTRACT In this study, a chelating resin ethylenediaminetetraacetic acid‐functionalized polystyrene‐g‐dimethylaminopropylamine resin (PS‐DMAPA‐EDTA) was synthesized by functionalizing polystyrene–dimethylaminopropylamine (PS‐DMAPA) resin with disodium ethylenediaminetetraacetate (Na 2 EDTA). The adsorption performance of both PS‐DMAPA and its EDTA‐modified derivative was examined for the removal of Cu(II), Cd(II), and Pb(II) ions from simulated wastewater. Characterization through FTIR, SEM, EDX, and XPS confirmed successful modification and revealed important morphological and elemental features of the resin. Batch adsorption experiments were performed to investigate the effects of initial concentration, sorbent dosage, pH, temperature, and contact time. Adsorption efficiency was highly dependent on pH and solid–liquid ratio, with maximum uptake occurring under mildly acidic conditions. The equilibrium data fitted the Langmuir isotherm with correlation coefficients exceeding 0.996, indicating monolayer adsorption. At 298 K, PS‐DMAPA‐EDTA exhibited enhanced sorption capacities of 45.82 mg g −1 for Cu(II), 47.92 mg g −1 for Cd(II), and 49.62 mg g −1 for Pb(II), clearly surpassing unmodified PS‐DMAPA. Kinetic analysis showed that adsorption followed the pseudo‐second‐order model, suggesting chemisorption as the rate‐controlling mechanism. Thermodynamic parameters indicated that the process was spontaneous and endothermic. Desorption studies with HNO 3 achieved efficient metal recovery, confirming the resin's recyclability. Overall, PS‐DMAPA‐EDTA demonstrates strong potential as a regenerable adsorbent for heavy metal remediation in aqueous systems.
Suthar et al. (Wed,) studied this question.