High efficiency removal of dissolved As(III) using iron nanoparticle-embedded macroporous polymer composites

Novel nanocomposite materials where iron nanoparticles are embedded into the walls of a macroporous polymer were produced and their efficiency for the removal of As(III) from aqueous media was studied. Nanocomposite gels containing alpha-Fe(2)O(3) and Fe(3)O(4) nanoparticles were prepared by cryopolymerisation resulting in a monolithic structure with large interconnected pores up to 100 mu m in diameter and possessing a high permeability (ca. 3 x 10(-3) ms(-1)). The nanocomposite devices showed excellent capability for the removal of trace concentrations of As(III) from solution, with a total capacity of up to 3 mg As/g of nanoparticles. The leaching of iron was minimal and the device could operate in a pH range 3-9 without diminishing removal efficiency. The effect of competing ions such as SO(4)(2-) and PO(4)(3-) was negligible. The macroporous composites can be easily configured into a variety of shapes and structures and the polymer matrix can be selected from a variety of monomers, offering high potential as flexible metal cation remediation devices. (C) 2011 Elsevier B.V. All rights reserved.