Fabrication of magnetic porous microspheres via (O1/W)/O2 double emulsion for fast removal of Cu2+ and Pb2+

A series of magnetic porous microspheres were prepared via (O-1/W)/O-2 double emulsion by grafting acrylic acid (AA) chains onto the backbone of hydroxyl propyl cellulose (HPC). The silane modified Fe3O4 particles and the surfactant polyglycerol polyricinoleate (PGPR) were used to stabilize the internal O-1/W Pickering emulsion and the (O-1/W)/O-2 double emulsion, respectively. The results indicated that the magnetic microspheres with the mean diameter about of 10 mu m had interconnected pore structure and the subsequent adsorption experiments demonstrated that the as-prepared magnetic porous microspheres showed the fast adsorption kinetics for removal of Cu2+ and Pb2+, and the adsorption equilibrium can be achieved within 3 min for Cu2+ and 5 min for Pb2+ regardless of higher (400 mg/l) or lower (100 mg/l) initial concentrations. Additionally, the high adsorption capacity with 227.34 mg/g for Cu2+ and 476.85 mg/g for Pb2+ and the excellent reusability by in situ magnetic separation were also presented. Therefore, the magnetic porous microspheres can be applied as a potential recyclable material for highly efficient removal of heavy metals. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.