Magnetic nanoparticles coated with aminated polymer brush as a novel material for effective removal of Pb(II) ions from aqueous environments

In the present study, a poly (vinylbenzyl chloride) grafted Fe₃O₄ nanoparticle (Fe₃O₄@PVBC) was prepared by surface-initiated reversible addition fragmentation chain transfer (SI-RAFT) polymerization and subsequently coated with tris (aminoethyl) amine (TAEA). Then, Fe₃O₄@PVBC-TAEA nanoparticles were utilized as a novel adsorbent for removal of Pb(II) from aqueous media and optimal adsorption conditions were determined with response surface methodology (RSM). The used adsorbent was characterized by using X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). RSM with central composite design (CCD) was carried out to evaluate the effect of initial pH, initial Pb(II) concentration (C₀, mg/L), adsorbent dosage (mg), and contact time (min). The optimum initial pH, C₀, adsorbent dosage, and contact time were found to be 5.88, 46.51 mg/L, 17.41 mg, and 108.21 min, respectively. The maximum removal efficiency and adsorption capacity were 97.07% and 129.65 mg/g under these conditions, respectively. The kinetic data revealed that the adsorption mechanism could be best explained by the pseudo-second-order and Weber-Morris models. The isotherm studies found that both the Langmuir and Freundlich isotherm models fitted the experimental data well. The thermodynamic analysis indicated that the adsorption nature is exothermic, applicable, and spontaneous.