Intensively competitive adsorption for heavy metal ions by PAMAM-SBA-15 and EDTA-PAMAM-SBA-15 inorganic–organic hybrid materials

EDTA modified Gn-PAMAM-SBA-15 (n = 1, 2, 3 and 4) inorganic–organic hybrid materials were successfully prepared with the structures characterized by XRD, FT-IR spectra and CP-MAS 13CNMR. The adsorption characters of the Gn-PAMAM-SBA-15 and EDTA modified materials were studied. The G3- and G4-PAMAM-SBA-15 samples showed high selectivities for Cr3+, Pb2+ and Zn2+ with the distribution coefficients Kd values larger than 1.25 × 104. When the EDTA modified adsorbents were chosen, the Kd for the Cu2+ and Ni2+ were increased. The metal loaded Gn-PAMAM-SBA-15 and EDTA modified samples may be regenerated.