| 内容提要: |
A novel magnetic silica gel adsorbent(Fe3O4-Si-COOH) was successfully prepared by introducing carboxyl group in situ to improve the performance for Pb(II), Zn(II) and Cd(II) adsorption. FT-IR, SEM, TEM, TGA, BET, XRD and VSM characterization suggested that Fe3O4-Si-COOH has been successfully prepared. The adsorption performance was evaluated by batch experiments with different initial concentration, ionic strength, contact time and pH. The adsorption kinetics data followed pseudo-second-order model and exhibited 3-stage intraparticle diffusion mode. Isothermal adsorption equilibrium data were best fitted by Freundlich model and the adsorption capacity were 155, 110, and 93 mg/g (initial concentration: 210 mg/L) for Pb(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ), respectively. In addition, the metal ions adsorbed adsorbent could be regenerated and the adsorption capacity of reused adsorbent could maintain 80.3% after five cycles. Hence, the Fe3O4-Si-COOH could be a kind of potential material for removing Pb(II), Zn(II) and Cd(II) from wastewater |