Optimization of the Photocatalytic Oxidation Process in Toluene Removal from Air

Document Type : Original Research Paper


1 Student Research Committee, School of Health, Qazvin University of Medical Sciences, P.O.Box 34197-659811, Qazvin, Iran

2 Department of Occupational Health, School of Health, Qazvin University of Medical Sciences, P.O.Box 34197-659811, Qazvin, Iran

3 Health Products Safety Research Center, Qazvin University of Medical Sciences, P.O.Box 34197-659811, Qazvin, Iran



The presence of volatile organic compounds in the indoor environment and their unwanted effects on human health are inevitable. That's why different methods have been proposed to remove them from air. The present study examines using photocatalytic reaction system along with TiO2 particles coated on stainless steel webnet to study direct conversion of toluene using a new design. The study was carried out using UV radiation in a dynamic concentrator system. SEM and XRD analyses were performed to characterize prepared catalysts. Here, the aim was to employ photocatalytic oxidation (PCO) to optimize removal efficiency and elimination capacity using response surface methodology (RSM). To this end, initial concentration and flow rate were selected as independent variables. High removal efficiency and elimination capacity were realized using optimal settings. The findings indicated that PCO process with a new design other than RSM was an option to treat air pollution containing volatile organic compounds.


Assadi, A. A., Bouzaza, A., Wolbert, D. and Petit, P. (2014). Isovaleraldehyde elimination by UV/TiO2 photocatalysis: comparative study of the process at different reactors configurations and scales. Environmental Science and Pollution Research, 21(19), 11178-11188. 
Assadi, A. A., Loganathan, S., Tri, P. N., Gharib-Abou Ghaida, S., Bouzaza, A., Tuan, A. N. and Wolbert, D. (2018). Pilot scale degradation of mono and multi volatile organic compounds by surface discharge plasma/TiO2 reactor: investigation of competition and synergism. Journal of hazardous materials, 357, 305-313. 
Bahri, M. and Haghighat, F. (2014). Plasma‐B ased Indoor Air Cleaning Technologies: The State of the Art‐R eview. CLEAN–Soil, Air, Water, 42(12), 1667-1680. 
Bahri, M., Haghighat, F., Rohani, S. and Kazemian, H. (2016). Impact of design parameters on the performance of non-thermal plasma air purification system. Chemical Engineering Journal, 302, 204-212. 
Choi, W., Ko, J. Y., Park, H. and Chung, J. S. (2001). Investigation on TiO2-coated optical fibers for gas-phase photocatalytic oxidation of acetone. Applied Catalysis B: Environmental, 31(3), 209-220. 
Das, J., Rene, E. R. and Krishnan, J. (2018). Photocatalytic degradation of volatile pollutants. J Environ Chem Toxicol Vol, 2(2). 
Emamjomeh, M. M., Jamali, H. A., Naghdali, Z. and Mousazadeh, M. (2019). Carwash wastewater treatment by the application of an environmentally friendly hybrid system: an experimental design approach. Desalination and water treatment, 160, 171-177. 
Fan, Z., Lioy, P., Weschler, C., Fiedler, N., Kipen, H. and Zhang, J. (2003). Ozone-initiated reactions with mixtures of volatile organic compounds under simulated indoor conditions. Environmental Science & Technology, 37(9), 1811-1821. 
Haghighat, F., Lee, C.-S., Pant, B., Bolourani, G., Lakdawala, N. and Bastani, A. (2008). Evaluation of various activated carbons for air cleaning–Towards design of immune and sustainable buildings. Atmospheric environment, 42(35), 8176-8184. 
Jamali, H. A. and Moradnia, M. (2018). Optimizing functions of coagulants in treatment of wastewater from metalworking fluids: prediction by RSM method. Environmental Health Engineering and Management, 5(1), 15-21. 
Khayet, M., Sanmartino, J., Essalhi, M., García-Payo, M. and Hilal, N. (2016). Modeling and optimization of a solar forward osmosis pilot plant by response surface methodology. Solar Energy, 137, 290-302. 
Klepeis, N. E., Nelson, W. C., Ott, W. R., Robinson, J. P., Tsang, A. M., Switzer, P., . . . Engelmann, W. H. (2001). The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. Journal of Exposure Science & Environmental Epidemiology, 11(3), 231-252. 
Liang, W., Li, J. and He, H. (2012). Photo-catalytic degradation of volatile organic compounds (VOCs) over titanium dioxide thin film. Advanced Aspects of Spectroscopy, 12, 341-372. 
Mamaghani, A. H., Haghighat, F. and Lee, C.-S. (2017). Photocatalytic oxidation technology for indoor environment air purification: The state-of-the-art. Applied Catalysis B: Environmental, 203, 247-269. 
Medina-Valtierra, J., Moctezuma, E., Sánchez-Cárdenas, M. and Frausto-Reyes, C. (2005). Global photonic efficiency for phenol degradation and mineralization in heterogeneous photocatalysis. Journal of Photochemistry and Photobiology A: Chemistry, 174(3), 246-252. 
Merajin, M. T., Sharifnia, S., Hosseini, S. and Yazdanpour, N. (2013). Photocatalytic conversion of greenhouse gases (CO2 and CH4) to high value products using TiO2 nanoparticles supported on stainless steel webnet. Journal of the Taiwan Institute of Chemical Engineers, 44(2), 239-246. 
Mo, J., Zhang, Y. and Xu, Q. (2013). Effect of water vapor on the by-products and decomposition rate of ppb-level toluene by photocatalytic oxidation. Applied Catalysis B: Environmental, 132, 212-218. 
Mohseni, M. and Taghipour, F. (2004). Experimental and CFD analysis of photocatalytic gas phase vinyl chloride (VC) oxidation. Chemical Engineering Science, 59(7), 1601-1609. 
Naghdali, Z., Sahebi, S., Mousazadeh, M. and Jamali, H. A. (2020). Optimization of the forward osmosis process using aquaporin membranes in chromium removal. Chemical Engineering & Technology, 43(2), 298-306. 
Queffeulou, A., Geron, L. and Schaer, E. (2010). Prediction of photocatalytic air purifier apparatus performances with a CFD approach using experimentally determined kinetic parameters. Chemical Engineering Science, 65(18), 5067-5074. 
Raupp, G. B., Alexiadis, A., Hossain, M. M. and Changrani, R. (2001). First-principles modeling, scaling laws and design of structured photocatalytic oxidation reactors for air purification. Catalysis Today, 69(1-4), 41-49. 
REZAEI, A., POURTAGHI, G. H., Khavanin, A., SARAF, M. R., HAJIZADEH, E. and Valipour, F. (2007). Elimination of toluene by Application of ultraviolet irradiation on TiO2 nano particles photocatalyst. 
Shang, J., Li, W. and Zhu, Y. (2003). Structure and photocatalytic characteristics of TiO2 film photocatalyst coated on stainless steel webnet. Journal of Molecular Catalysis A: Chemical, 202(1-2), 187-195. 
Shiue, A., Kang, Y.-H., Hu, S.-C., Jou, G.-t., Lin, C.-H., Hu, M.-C. and Lin, S.-I. (2010). Vapor adsorption characteristics of toluene in an activated carbon adsorbent-loaded nonwoven fabric media for chemical filters applied to cleanrooms. Building and environment, 45(10), 2123-2131. 
Talaiekhozani, A., Rezania, S., Kim, K.-H., Sanaye, R. and Amani, A. M. (2021). Recent advances in photocatalytic removal of organic and inorganic pollutants in air. Journal of Cleaner Production, 278, 123895. 
Tanha, F., Rangkooy, H., Jaafarzadeh, N., Valipour, F. and Arefian, I. (2017). A study on photocatalytic removal of Toluene from air using ZnO-SnO2 coupled oxide immobilized on Activated Carbon. Iran Occupational Health, 13(6), 1-9. 
van Walsem, J., Roegiers, J., Modde, B., Lenaerts, S. and Denys, S. (2019). Proof of concept of an upscaled photocatalytic multi-tube reactor: A combined modelling and experimental study. Chemical Engineering Journal, 378, 122038. 
Vildozo, D., Ferronato, C., Sleiman, M. and Chovelon, J.-M. (2010). Photocatalytic treatment of indoor air: Optimization of 2-propanol removal using a response surface methodology (RSM). Applied Catalysis B: Environmental, 94(3-4), 303-310. 
Vione, D., Minero, C., Maurino, V., Carlotti, M. E., Picatonotto, T. and Pelizzetti, E. (2005). Degradation of phenol and benzoic acid in the presence of a TiO2-based heterogeneous photocatalyst. Applied Catalysis B: Environmental, 58(1-2), 79-88. 
Vizhemehr, A. K. and Haghighat, F. (2014). Modeling of gas-phase filter model for high-and low-challenge gas concentrations. Building and environment, 80, 192-203. 
Wang, S., Ang, H. and Tade, M. O. (2007). Volatile organic compounds in indoor environment and photocatalytic oxidation: State of the art. Environment international, 33(5), 694-705. 
Zhang, Y. (2013). Modeling and design of photocatalytic reactors for air purification: University of South Florida.
Zhong, L. and Haghighat, F. (2014). Ozonation air purification technology in HVAC applications. Ashrae Trans, 120(8). 
Zhong, L., Haghighat, F. and Lee, C.-S. (2013). Ultraviolet photocatalytic oxidation for indoor environment applications: Experimental validation of the model. Building and environment, 62, 155-166. 
Zhong, L., Lee, C.-S. and Haghighat, F. (2012). Adsorption performance of titanium dioxide (TiO2) coated air filters for volatile organic compounds. Journal of hazardous materials, 243, 340-349.