Poly(glycidyl methacrylate) microspheres (PGMA) with micron size were synthesized by dispersion polymerization method.Through two-step reactions with ethylenediamine (EDA) and polyethylenimine (PEI),the PEI-grafted PGMA microspheres (PGMA-PEI) were obtained.Subsequently this microspheres were applied for the removing of Cr(Ⅵ) from aqueous solution.The effects of adsorbent dose,pH value,initial Cr(Ⅵ) concentration,contact time,temperature,coexisting cations competition and reuse were studied by batch tests.Some promising results were reported.Adsorption is a convenient and efficient technology in the removing Cr(Ⅵ),with the advantages of low technological equipment consumption,easy recovery of metal ions,and reusability of the adsorbents[1].Amino-functionalized materials would be a good choice,since they can be easily protonated in acid environment and remove metal anion via electrostatic interaction[2],ion exchange[3],as well as coordination interaction[4].In this study,PGMA microspheres with micron size were prepared by dispersion polymerization method,and then modified by two-step amination reactions with EDA and PEI.Subsequently,the adsorption behaviors of PGMA-PEI microspheres for the removal of Cr(Ⅵ) from aqueous solution were investigated by a series of batch texts.The effects of adsorbent dose,pH value,initial Cr(Ⅵ) concentration,contact time,temperature,coexisting cations competition,reuse and adsorption mechanism were studied.The results showed that Cr(Ⅵ) adsorption denpended significantly on pH and the optimal pH value was found at pH=2.The adsorption isotherms of PGMA-PEI microspheres for Cr(Ⅵ) fitted well with Langmuir model,with maximum adsorption capacities of 462.96,485.44,505.05 mg g-1 for PGMA-PEI600,PGMA-PEI1800 and PGMA-PEI10172 microspheres,respectively.Adsorption reached equilibrium within 10 min and kinetics data obeyed pseudo-second-order model well.The thermodynamic parameters (ΔG,ΔH,ΔS) obtained revealed the adsorption process was endothermic and spontaneous in mature.Competition from coexisting cations (Cl-,NO3-,SO42-,H2PO4-,HPO42-) was found insignificant.The adsorption capacity did not change noticeably after four successive adsorption-desorption cycles.