Efficient As(III) Removal by Novel MoS2-Impregnated Fe-Oxide–Biochar Composites: Characterization and Mechanisms

摘要

Sorbents that efficiently eliminate toxic metal(loid)s from industrial wastes are required for the protection of the environment and human health. Therefore, we demonstrated efficient As(III) removal by novel, eco-friendly, hydrothermally prepared MoS_(2)-impregnated FeO_(x) @BC800 ([email?protected]). The properties and adsorption mechanism of the material were investigated by X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The synergistic effects of FeO_(x) and MoS_(2) on [email?protected] considerably enhanced As(III)-removal efficiency to ≥99.73% and facilitated superior As(III) affinity in aqueous solutions (K _(d) ≥ 10~(5) mL g~(–1)) compared to those of FeO_(x) @BC800 and [email?protected], which showed 37.07 and 17.86% As(III)-removal efficiencies and K _(d) = 589 and 217 mL g~(–1), respectively, for an initial As(III) concentration of ～10 mg L~(–1). The maximum Langmuir As(III) sorption capacity of [email?protected] was 28.4 mg g~(–1). Oxidation of As(III) to As(V) occurred on the [email?protected] composite surfaces. Adsorption results agreed with those obtained from the Freundlich and pseudo-second-order models, suggesting multilayer coverage and chemisorption, respectively. Additionally, [email?protected] characteristics were examined under different reaction conditions, with temperature, pH, ionic strength, and humic acid concentration being varied. The results indicated that [email?protected] has considerable potential as an eco-friendly environmental remediation and As(III)-decontamination material.