Introduction: Styrene monomer is a volatile organic compound that has many applications particularly in plastic, rubber and paint industries. According to the harmful effects of these compounds on human and environment, reducing and controlling of them seem necessary. Therefore, in this study removal of styrene was investigated using the photocatalytic process of titanium dioxide nanoparticles stabilized on ZSM-5. Methods: After stabilization of titanium dioxide nanoparticles on ZSM-5 zeolite, Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and X-ray diffractometry (XRD) analyses were used to determine the characteristics of nanoparticles. Experiments were conducted at ambient temperature in a laboratory scale. Concentrations of the produced styrene in the experiments were 50 and 300 ppm, and the input flow rate was 1 l/min. Results: The images and spectra obtained through XRD and SEM-EDAX showed that nano-catalysts are well-stabilized. The results showed that by increasing the input concentration of styrene from 50 to 300 ppm, the photocatalytic removal efficiency was reduced. Also, adsorption capacities of the catalyst bed in concentrations of 50 and 300 ppm were calculated 16.3 and 19.4 mg/g of adsorbent, respectively. Conclusions: The results show that the use of hybrid bed can increase the removal efficiency of contaminants. Also, due to low cost of application of these systems compared to conventional methods, it is recommended that more comprehensive studies be conducted regarding the optimization of the parameters affecting the process of photocatalytic removal.
Toluene is a colorless and flammab1le liquid with the same solubilizing capacity as benzene that is in many cases used as an alternative to benzene, because of the uncertainty of being carcinogens. Workers can be exposed to toluene by breathing the chemical. To avoid inhalation and dermal effects caused by exposure to toluene, solutions such as adsorption, thermal oxidation, membrane separation and photocatalytic processes are applied. In this study, removal of toluene vapors with modified natural zeolite and titanium dioxide nanoparticles was discussed. The natural zeolite was modified using chemical and thermal methods. The samples characterized by Brunauer-Emmet-Teller, Barrett-Joyner-Halenda, X-ray diffraction and scanning electron microscopy tests. After stabilization of TiO2 nanoparticles, the removal efficiency for the toluene vapors at a concentration of 50, 150 and 300 ppm were evaluated using a dynamic system. The results showed that the zeolite has a very porous surface and after modifying the context its specific surface area increased 2.54 times. The results of the adsorption capacity calculation and photocatalytic process showed that modified zeolite samples-TiO2 bed has greater efficiency in the adsorption capacity and better photocatalytic activity than a Ze-TiO2 bed. Ze-TiO2 bed was able to remove 26% of toluene vapors at the concentration of 50 ppm and inlet flow rate of 1 L/m, which was 1.26 times more than a bed Ze-TiO2. According to the results of this study, while modifying the natural zeolite increased desirable properties such as specific surface area and Si/Al ratio, but in comparison with similar studies with synthetic bed such as zeolite Y and ZSM-5, could not achieve desired results in a photocatalytic activity for its application in industry. However, because of its abundance in the world and Iran and therefore low cost of preparation and also due to its unique characteristics, it is recommended that more studies to be done about modifying and its application in photocatalytic processes.
Background and Aim: Styrene monomer is a volatile organic compound that is used extensively in the manufacture of plastics, rubber, and resins. Many health effects caused by continuous exposure to styrene have been reported by different organizations of health and safety. This study was carried out to determine the efficiency of photocatalytic removal of styrene by using zinc oxide nanoparticles immobilized on diatomite. Materials and Methods: This study was done on a laboratory scale, in which zinc oxide nanoparticles with the size of 20 to 40 nm and 5% concentration were stabilized on the natural diatomite and then irradiated with UV light as a photocatalytic agent in order to degrade styrene vapors. Results: In this study, the concentrations of 20, 100, and 300 ppm styrene were passed through a reactor containing diatomite substrate covered with nano-ZnO (MDi/ZnO 5%). The results showed that thr bed of MDi/ZnO 5% could remove 35 percent of styrene vapors at concentrations of 20 ppm and a flow rate of 1 lit /min. Conclusion: Due to the removal efficiency of 35% styrene vapors by MDi/ZnO 5% substrate and properties such as low cost and availability of diatomite and zinc oxide, it can be used from the bed to remove volatile organic compounds, but in comparison to similar studies with other beds such as natural and synthetic zeolites and activated carbon, it could not achieve the desired results in a photocatalytic activity for its application in industry. However, because of its abundance in the world and Iran, low cost of preparation, and also its unique characteristics, further studies are recommended about its modification and application in photocatalytic processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.