Design of Magnetic Attapulgite/Fly Ash/Poly(acrylic acid) Ternary Nanocomposite Hydrogels and Performance Evaluation as Selective Adsorbent for Pb2+ Ion

A facile inverse suspension polymerization approach was developed for the preparation of the magnetic attapulgite/fly ash/poly(acrylic acid) (ATP/FA/PAA) ternary nanocomposite hydrogels, after the inorganic materials were in situ modified. In the optimized preparation condition obtained via the L-9(3(4)) orthogonal experiments, about 95% of the monomer had been grafted onto the inorganic materials to form the three-dimensional cross-linking network of the ternary nanocomposite hydrogels. The ternary nanocomposite hydrogels exhibited good adsorption selectivity toward the Pb2+ ion, and the adsorbed ion could be completely desorbed with HCl aqueous solution. Furthermore, the ternary nanocomposite hydrogels possessed high mechanical stability and magnetic property. These features as well as their low cost make them a potential adsorbent for treating Pb2+-contaminated water.