Efficient capture of arsenic from industrial wastewater by Fe-doped zirconium-based metal–organic frameworks

Abstract

Arsenic is a metalloid element that is highly toxic. Due to various reasons, arsenic pollution, especially water pollution, seriously affects people's lives. Therefore, in this study, a novel material (Fe-UiO-67) was successfully synthesized for arsenic removal by a simple one-pot method. Metal doping can increase the contact area between an MOF and a solution without changing the structure of the MOF and make up for the lack of active sites in the material. The synthesis and adsorption mechanism of the as-obtained adsorbent was demonstrated by a series of characterizations, such as scanning electron microscopy (SEM-EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results show that Fe incorporation led to the formation of Fe-UiO-67 by substituting Zr and ligating with an organophore (4,4′-H2BPDC). Pseudo-secondary kinetics and Langmuir isotherm models could adequately describe the adsorption behavior of arsenic on Fe-UiO-67, which demonstrated high adsorption performance under alkaline conditions (pH 10), and its adsorption capacity could reach 517.9 mg g⁻¹, surpassing that of most previously reported adsorbents. Moreover, the adsorbent still showed high adsorption performance after four adsorption–desolution cycles, indicating that the material has good regeneration capability.