Research
| Title： | Adsorption of Pb(II) and Cd(II) by magnetic activated carbon and its mechanism |
|---|---|
| First author： | Zhang, Zhen; Wang, Tao; Zhang, Huixue; Liu, Yonghong; Xing, Baoshan |
| Journal： | SCIENCE OF THE TOTAL ENVIRONMENT |
| Years： | 2021 |
| DOI： | 10.1016/j.scitotenv.2020.143910 |
| Abstract： | Magnetized activated carbons (MAC) were prepared by activating rape straw powder, and pyrolyzing at different temperatures, then magnetizing activated carbon by hydrothermal method. MAC-300 had the largest adsorption capacity of Pb(II) (253.2 mg/g) and Cd(II) (733 mg/g). The adsorption isotherms and kinetics could conform to the Freundlich model and pseudo-second-order kinetic model, respectively, indicating that the adsorptive behavior of the adsorbent mainly depends on the non-uniform active points on the surface of the material. Meanwhile, the thermodynamic parameters showed that the adsorption of Pb(II) and Cd(II) by MAC-300 was a spontaneous and endothermic reaction.The adsorption capacity of MAC-300 could be improved by properly increasing the pH of the original solution. There was competitive adsorption when high-valent ions were present in solution. In combination with various characterizations and comparison tests of samples after adsorption, the adsorption mechanisms include surface electrostatic attraction, surface complexation, and co-precipitation. The results indicated that the MAC material was a potential material to remove heavy metal ions from the aqueous solution. (C) 2020 Elsevier B.V. All rights reserved. |
