Adsorption properties of arsenic on sulfated TiO2 adsorbents

Adsorption technologies are considered to be cost-effective solutions for the removal of toxic residues. In the present study, two types of sulfated TiO2 adsorbents, sulfated-TiO2(A) and sulfated-TiO2(B), were prepared by the wetness impregnation method, and tested for how effectively they could bind to, and hence, remove arsenic. These adsorbents were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (MR). The interaction of the arsenic with the sulfate group at the surface of the adsorbent can be deduced by the reduction in the peak intensity of the S-O bond at 1219 cm(-1), corresponding to the SO42- group. In particular, the number of Lewis and Bronsted acid sites was enhanced in the sulfated-Ti(OH)(4) adsorbents, which modulated the surface acidity of titania by controlling the electron density and facilitated the adsorption of arsenic. Our results confirmed that sulfated-TiO2(B) is 20% more efficient at removing arsenic, as compared to TiO2 (60%) and Ti(OH)(4) (64%). (C) 2019 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.