Assesment of dimethyl phthalate removal from aqueous phase using barium hexaferrite containing magnetic beads

[Display omitted] ► Magnetic beads were prepared for the removal of dimethyl phthalate (DMP). ► Total capacity of the beads was to be 96.2mg DMP per gram polymer. ► Adsorption isotherms, kinetics, and thermodynamics were elucidated. ► Magnetic beads were regenerated easily and reused for DMP adsorption. The barium hexaferrite (BaFe12O19) containing magnetic poly (ethylene glycol dimethacrylate-vinyl pyridine; mag-poly [EGDMA–VP]) beads (average diameter=53–212μm) were synthesized and characterized. Their use as an adsorbent in the removal of dimethyl phthalate (DMP) from an aqueous solution was investigated. The mag-poly (EGDMA–VP) beads were prepared by copolymerizing of 4-vinyl pyridine (VP) with ethylene glycol dimethacrylate (EGDMA). The mag-poly (EGDMA–VP) beads were characterized by N2 adsorption/desorption isotherms (BET), vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), elemental analysis, scanning electron microscope (SEM), and swelling studies. At a fixed solid/solution ratio, the various factors affecting the adsorption of DMP from aqueous solutions such as pH, initial concentration, contact time, and temperature were analyzed. The maximum DMP adsorption capacity of the mag-poly (EGDMA–VP) beads was determined as 96.2mg/g at pH 3.0, 25°C. All the isotherm data can be fitted with both the Langmuir and the Dubinin–Radushkevich isotherm models. The pseudo-first-order, pseudo-second-order, Ritch-second-order, and intraparticle diffusion models were used to describe the adsorption kinetics. The thermodynamic parameters obtained indicated the exothermic nature of the adsorption. The DMP adsorption capacity did not change after 10 batch successive reactions, demonstrating the usefulness of the magnetic beads in applications.