Removal of arsenic(v) from aqueous solutions using sulfur-doped FeO nanoparticles.

In this study, magnetic sulfur-doped FeO nanoparticles (FeO:S NPs) were applied as adsorbents for the removal of As(v). FeO:S NPs were fabricated by a two-step route, which included low-temperature mixing and high-temperature sintering. The as-prepared FeO: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, which was much better than undoped FeO nanoparticles (20.24 mg g). 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 , SO , and CO had no significant effect on As(v) adsorption and the adsorbent worked well in actual smelting wastewater. XPS and FTIR spectra of FeO:S NPs before and after As(v) adsorption showed that Fe-OH groups played a significant role in the adsorption mechanisms. Moreover, the magnetic FeO:S NPs adsorbents after adsorption could be rapidly separated from wastewater with an external magnetic field. Therefore, FeO:S NPs could be an ideal candidate for the removal of As(v) from water.