Magnetic nanoadsorbents with amino-functionalized polymers for magnetic separation removal of copper ion

The adsorption of copper ions on magnetic adsorbents with amino-functionalized polymers (DETA/SiO₂/Fe₃O₄) has been investigated. In addition, the structure and characterization of magnetic nano-adsorbents were confirmed using FTIR, TGA, TEM, VSM, and BET. The results showed that DETA/SiO₂/Fe₃O₄ exhibited a paramagnetic behaviour and could be easily recovered and quickly separated from a suspension solution. The optimum pH level for adsorption of copper ions was proposed to be in the range of pH level from 5 to 6, and the maximum adsorption capacity (q) and activated energy (E) at 298 K was 13.459 mg g^-1 and 22.421 kJ mol^-1, respectively. The copper ions adsorption behaviour by DETA/SiO₂/Fe₃O₄ was in good agreement with the Langmuir isotherm rather than Freundlich equation. A pseudo-second-order model could best describe the adsorption kinetics, and the optimal condition of copper ions desorption (99%) from DETA/SiO₂/Fe₃O₄ was provided by 1.0 M HNO₃. The novel magnetic nano-adsorbents could not only be regenerated by HNO₃ solutions but also reused by the recovery of magnetic force without requiring further downstream treatment.