Evaluation of magnetic material IIP@GO-Fe₃O₄ based on Kesambi wood (Schleichera oleosa) as a potential adsorbent for the removal of Cr(VI) from aqueous solutions

Magnetic composite material modified ion imprinting polymer (IIP@GO-Fe₃O₄) based on GO from kesambi wood (Schleichera oleosa) was successfully synthesized by using a precipitation method. The physico-chemical characterization uses XRD, FTIR, BET-BJH and SEM-EDX. IIP@GO-Fe₃O₄ was applied to adsorb Cr(VI) from the water sample by utilizing the batch system. Various adsorption parameters for Cr(VI) such as adsorbent mass, pH, contact time and temperature were optimized in this investigation. The Cr(VI) maximum adsorption occurred when the adsorbent mass usage 0.04 g, pH 2, 40 min of contacts and at the temperature of 323 K. In this study ten kinetic and eight isothermal adsorption models were used to investigate the adsorption mechanism of Cr(VI) onto IIP@GO-Fe₃O_4. The kinetic modelling shows that the adsorption of Cr(VI) onto IIP@GO-Fe₃O₄ corresponds to the pseudo-second-order (PSO) model, while the adsorption isotherm corresponds to the Dubinin-Radushkevich (DKR) model with an adsorption capacity of 8.502 mg/g. The thermodynamic study has shown that the adsorption process can take place at a temperature of 323 K. The result showed that a higher adsorption selectivity on IIP@GO-Fe₃O₄ compares to NIP@GO-Fe₃O_4. The adsorbent materials gave better reusability because their adsorptive capacity remained at the same level (although it was used at least ten times).