A novel modification method for polystyrene microspheres with dithizone and the adsorption properties for Pb2+

Dithizone is known to be very effective for heavy metal ions retention and widely used as developer in detection methods. To explore a novel surface modified polymer microspheres, this paper prepared a novel modified polystyrene (PS-g-D) microspheres by grafting dithizone as the complexing agent and developer on the surface of PS microspheres. The structure of PS-g-D was analyzed by FT-IR, and the formation of dithizone grafted PS microspheres was proved. The thermal stability and surface morphology of PS and modified PS were studied by TGA and SEM. PS-g-D had a uniform diameter of about 1 μm and exhibited a good thermal stability. The Pb2+ removal increased and reached up to 99% with the decrease of initial Pb2+ concentrations. The study of the isotherms model showed that the adsorption between PS-g-D and Pb2+ is consistent with the Langmuir and Temkin adsorption isotherm models. The adsorption kinetics of PS-g-D is described well by the pseudo-second-order model. It can be seen that the modified PS microspheres exhibit a good adsorption property, and has real potential as a novel adsorbent for water treatment industry due to the introduction of dithizone as complexing agent and developer.