Effect Of Host Pore Structure On Cu(Ⅱ) Removal By Polymer-supported Nano-Hydrous Manganese Dioxide

Four nano-hydrated manganese dioxide (HMO)-encapsulated composites of similar HMO loadings but different pore structures (HPS-X-HMO)were fabricated for Cu(II) removal from water to elucidate the role of host pore structure on properties the resultant nanocomposites. Several hyper-cross-linked polystyrene (HPS) resins of the same particle size ranges but different pore structures were synthesized as the hosts. All the nancomposite adsorbents were well characterized by N2adsorption-desorption at77K, SEM and TEM images, XRD and FTIR spectroscopy. Batch experiments were conducted to investigate the effect of solution pH, initial Cu(II) concentration, contact time and some competing ions on Cu(II) adsorption by different HPS-X-HMO. The interactions involved in the adsorption process were preliminarily explored by FT-IR technique.Results demonstrated that the particle size of HMO aggregates decreased with decreasing pore size of HPS. As a result, the adsorption capacity of four composite adsorbents increased as the pore size of HPS decreased. Adsorption isotherm can be described by the Freundlich model. Intra-particle diffusion model was employed to determine the rate-limiting step in the adsorption process, and results suggested that both external and intraparticle diffusion was contributed to adsorption kinetics of Cu(II). All the results indicated that the pore structure of the support materials would play an important role in the performance of nanoparticle-loaded composite adsorbents for pollutants removal from aqueous solution.