Removal of arsenic(v) from aqueous solutions using sulfur-doped Fe(3)O(4) nanoparticles

In this study, magnetic sulfur-doped Fe(3)O(4) nanoparticles (Fe(3)O(4):S NPs) were applied as adsorbents for the removal of As(v). Fe(3)O(4):S NPs were fabricated by a two-step route, which included low-temperature mixing and high-temperature sintering. The as-prepared Fe(3)O(4):S NPs could effectively remove As(v) under a wide pH range of 2–10 and presented a high As(v) adsorption capacity of 58.38 mg g(−1), which was much better than undoped Fe(3)O(4) nanoparticles (20.24 mg g(−1)). Adsorption experiments exhibited a pseudo-second-order model of adsorption kinetics and a Langmuir isotherm model of adsorption isotherms. Additionally, the coexisting ions such as NO(3)(−), SO(4)(2−), and CO(3)(2−) had no significant effect on As(v) adsorption and the adsorbent worked well in actual smelting wastewater. XPS and FTIR spectra of Fe(3)O(4):S NPs before and after As(v) adsorption showed that Fe–OH groups played a significant role in the adsorption mechanisms. Moreover, the magnetic Fe(3)O(4):S NPs adsorbents after adsorption could be rapidly separated from wastewater with an external magnetic field. Therefore, Fe(3)O(4):S NPs could be an ideal candidate for the removal of As(v) from water.