Removal of cadmium and lead ions from water by sulfonated magnetic nanoparticle adsorbents.

A new adsorbent, FeO sulfonated magnetic nanoparticle (FeO-SOH MNP), was developed for heavy metal ions removal from water, which could be effectively separated from the solution owing to the superparamagnetic property. The nanoparticles can be used to remove heavy metal ions due to the additional active site, "sulfo-group", introduced by the AMPS branches grafted onto the iron oxide. The as-synthesized materials were characterized by SEM, TEM, FT-IR and BET. The FTIR, XPS and Zeta potential were used to describe the adsorption mechanism. The FeO-SOH MNPs showed rapid removal for Pb and Cd with maximum of adsorption capacity of 108. 93 and 80.9mg/g at 25°C, respectively. The adsorption isotherms for Pb and Cd fitted better with Langmuir than Freundlich models, indicated that the processes of the removal of Pb and Cd could follow a kind of similar adsorption manner. The adsorption kinetic was consistent with pseudo-second-order model. Furthermore, the reuse experiments results showed the adsorbent might have potential in treating heavy metal ions pollution in water.