Adsorption and photocatalytic removal of SO2 using natural and synthetic zeolites-supported TiO2 in a solar parabolic trough collector

Abstract

Performance of adsorption and photocatalysis processes for SO₂ removal was studied using a new synthetic zeolite prepared from stone cutting sludge and a natural zeolite (clinoptilolite) as the supports of TiO₂ photocatalyst under different sunlight irradiation intensities in a photoreactor equipped with parabolic trough collector. The samples were characterized by X-ray fluorescence spectrometer, X-ray diffraction, surface area, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, UV–Vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The optimum sunlight irradiation for SO₂ photodegradation was observed around the noonday with the high light intensity (125.0–135.0 mWcm⁻²) resulting in about 35% removal efficiency. The highest SO₂ removal by adsorption was 31.7% and 27.6% for TiO₂-natural and synthetic zeolites, respectively. The maximum SO₂ removal efficiency by the composites of TiO₂-Ze and TiO₂-Cp through the adsorption and photocatalytic processes was 70.0% and 78.8%, respectively. The regeneration of composite by washing with water was a simple and cost-effective method with more than 95% efficiency. Overall, both natural and synthetic zeolites could be used as efficient supports of TiO₂ photocatalysts for the removal of SO₂ under sunlight irradiation.

https://doi.org/10.1016/j.jclepro.2021.127376