Adsorption of Sulfur Dioxide on Clinoptilolite/Nano Iron Oxide and Natural Clinoptilolite

Abstract

Background: Sulfur dioxide gas is known to include pollutants that are harmful to human health and the environment. Therefore, due to the increase of industrial activities, SO2 gas pollution control is very important. Objectives: The purpose of this study was to investigate the efficiency of sulfur dioxide removal by iron oxide nanoparticles deposited on clinoptilolite zeolite. Methods: Two materials, natural clinoptilolite and clinoptilolite containing iron oxide nanoparticles, were used as adsorbents of SO2. Both materials were characterized via scanning electron microscopy imaging, infrared spectroscopy, and N2 porosimetry, along with the determination of the thermodynamic properties and kinetics of SO2 adsorption. Therefore, breakthrough experiments were carried out at different temperatures and with different contact times. Sulfur dioxide adsorption of a real sample was considered for both adsorbents. Results: The adsorption efficiency of SO2 in the synthetic and actual sample was obtained at 80.3% and 66.7%, respectively, under optimum conditions (temperature of 25°C and duration of 28.5 minutes) by modified zeolite with iron oxide nanoparticles. The removal percentage average of SO2 was also obtained in the synthetic and actual sample at 43.8% and 31.3%, respectively, by zeolite in optimum conditions (temperature of 25°C and contact time of 20.5 minutes). The adsorption of SO2 with both adsorbents followed the pseudo-second-order equation and the adsorption process was an exothermic and spontaneous process. Conclusions: The addition of these iron oxide nanoparticles had a positive impact on the surface area and on SO2 capacity.