Photocatalytic treatment based on TiO2 for a coal mining drainage

Abstract

The aim of the present work was to evaluate the effectiveness of a heterogeneous photocatalyst based on TiO2 in the treatment of coal mining drainage which contains a variety of heavy metals and high concentration sulfates and sulfides. The photocatalytic behavior of the commercial reference Sigma Aldrich and the different materials synthesized using the Sol-gel methodology with surface modifications using sulfation and fluorination processes were analyzed. To find a possible correlation between the physicochemical properties of photocatalysts and their behavior, a characterization was carried out using X-Ray Diffraction (XRD), X-Ray Fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FT–IR), UV–Vis diffuse reflectance Spectra (UV-Vis DRS), N2 physisorption, X-ray photoelectron spectroscopy (XPS), and particle size analysis. Results indicated that the modification of the TiO₂ prepared in the laboratory using sulfation and fluorination allowed the successful control of the physicochemical properties of this oxide. However, commercial TiO2 showed the greatest effectiveness in removing metals such as: Fe, Cu, Cr, and As after a photocatalytic reaction for a maximum of 1 hour under continuous nitrogen flow and a light intensity of 120 W/m2.

ZNO/TIO2 and ZNO/NB2O5 as effective systems for the treatment of enteric bacteria and commercial dyes

“…The main signal for T iO 2 is observed around 2θ = 25.25°, which indicates the presence of only the Anatase crystalline phase for this material [4,16]. In the case of N b 2 O 5 , the main signal can be observed around 2θ = 28.58°due to the plane (100), corresponding to the crystalline N b 2 O 5 in the hexagonal phase [13,16].…”

“…It has also been reported that the heterojunction formation between mixed oxides such as ZnO, T iO 2 , and N b 2 O 5 is an effective way to achieve a better separation of photogenerated charges. This improves the photocatalytic response of these materials [13], and therefore, the effectiveness of the composed materials in wastewater treatment by photocatalytic processes [13][14][15].…”