Mesoporous Magnetic Ferrum-Yttrium Binary Oxide: a Novel Adsorbent for Efficient Arsenic Removal from Aqueous Solution

Mesoporous magnetic ferrum-yttrium (Fe-Y) binary oxide was first synthesized as an effective absorbent for the removal of arsenite [As(III)] and arsenate [As(V)] from aqueous solution. The adsorbent was characterized by field emission scanning electron microscopy (FESEM), energy dispersion X-ray spectrometer (EDX), vibrating sample magnetometer (VSM), X-ray photoelectron spectra (XPS). A series of batch experiments were conducted to estimate the adsorption capacity of arsenic and to investigate the effect of solution pH and coexisting anions on the removal of arsenic. The results demonstrate that the adsorption of arsenic by the adsorbent was pH-dependent. The optimal adsorption was realized at pH 4 for As(V) and at pH 5 for As(III). The maximum capacity of As(V) and As(III) obtained in this study was 200 and 73 mg g−1, respectively. The anions concluding sulfate, chloride, and nitrate exerted a weak impact on As(V) removal, whereas phosphate greatly suppressed the adsorption of both As(III) and As(V) through competing with arsenic species for active adsorption sites on the surface of the adsorbent. All above suggest that the novel adsorbent not only works efficiently for arsenic removal, but also is stable in a wide solution pH range, which is conducive to the practical application for wastewater treatment.