Magnetite nanoplates decorated on anodized aluminum oxide nanofibers as a novel adsorbent for efficient removal of As(III)

Abstract

In this study, arsenic as an environmental top-ranked hazardous substance was efficiently removed by a novel adsorbent fabricated by magnetite Fe3O4 nanoplates decorated on anodized aluminum oxide (AAO) nanofibers. AAO nanofibers were prepared by anodic polarization method, and then Fe3O4 nanoplates were grown on AAO-based substrate by hydrothermal method to fabricate AAO/Fe3O4 nanosorbent. Morphology of the fabricated adsorbents was characterized by field emission scanning electron microscopy (FE-SEM), and their crystallinity was studied by X-ray diffraction (XRD). Arsenic (III) removal potential of the proposed adsorbent from contaminated water samples was investigated by the determination of As(III) amounts in the samples by inductively coupled plasma optical emission spectroscopy before and after adsorption process at sub-μg L−1 levels. The results showed that without pre- and post-treatments such as pH adjustment, As(III) was removed effectively from contaminated water samples by using the proposed adsorbent. AAO/Fe3O4 sorbent showed excellent ability to remove 0.1 mg L−1 As(III) from water samples up to 96 % uptake. Freundlich adsorption isotherm model was used to interpret the As(III) adsorption on proposed sorbent. The Freundlich isotherm parameters n and k F were obtained to be 2.2 and 10.2, respectively, representing the high affinity of proposed adsorbent for arsenic removal.