Novel Magnetically Doped Epoxide Functional Cross-linked Hydrophobic Poly(lauryl methacrylate) Composite Polymer Particles for Removal of As(III) from Aqueous Solution

Superparamagnetic iron oxide nanoparticles have been found suitable as adsorbent materials for the removal of As­(III) from aqueous solution. In this investigation, the usefulness of magnetically doped epoxide functional cross-linked poly­(lauryl methacrylate) (PLMA) composite polymer particles as an adsorbent bed for the removal of As­(III) ions has been evaluated. The epoxide functional composite polymer particles are prepared by seeded polymerization of glycidyl methacrylate (GMA) in the presence of cross-linked poly­(LMA-divinylbenzene), P­(LMA-DVB), seed particles. The surface of prepared composite polymer particles is finally doped with Fe₃O₄ nanoparticles. The epoxide functional magnetic composite polymer particles have been named as P­(LMA-DVB)/PGMA/Fe₃O₄. A pH and contact time dependent adsorption behavior of As­(III) is observed on P­(LMA-DVB)/PGMA/Fe₃O₄ composite polymer particles. The equilibrium (q_e) reached after 180 min and a highest removal efficiency of 57.98% is attained at pH 5.0. The adsorption isotherm strictly followed Langmuir model with maximum theoretical adsorption capacity (q_m) reaching 66.23 mg/g of particles at 323 K. Batch kinetic sorption experiments showed that a pseudo-second-order rate kinetic model is more applicable. The study of thermodynamic equilibrium parameters suggested that adsorption of As­(III) is endothermic and spontaneous. The adsorbent could be regenerated partially by treatment with 0.01 M NaOH, retaining about 40% of the adsorption capacity after first time adsorption and then only slightly decreased.