عنوان مقاله [English]
Ethylene dichloride is one of the most important chlorinated hydrocarbons in the petrochemical industry, which is mainly used to produce vinyl chloride monomer, the main precurser of PVC production. Iran is one of the largest PVC producers in the world. During the production of 1000 kg of ethylene dichloride, about 0.4 m3 wastewater is produced containing 50-200 mg / L of ethylene dichloride. In this study, heterogeneous photocatalysis was used for degradation of this chlorinated hydrocarbon. PAni-TiO2 nanocomposite was immobilized on glass beads by a modified dip coating and heat attachment method. The morphology characteristics were confirmed by scanning electron microscope, energy dispersive X-ray spectroscopy and ultraviolet–visible spectroscopy. A pilot scale packed bed recirculating batch photocatalytic reactor was used for conducting photocatalytic experiments. response surface methodology based on central composite design was used to evaluate and optimize the effect of ethylene dichloride concentration, residence time, pH and coating mass as independent variables on the photocatalytic degradation of ethylene dichloride as the response function. Based on the results, actual and RSM predicted results were well fitted with R2 of 0.9870, adjusted R2 of 0.9718 and predicted R2 of 0.9422. Optimum conditions were the ethylene dichloride concentration of 250 mg/L, reaction time of 240 min, pH of 5 and immobilized mass of 0.5 mg/cm2, which resulted in 88.84% photocatalytic degradation. Kinetic of the photocatalytic degradation at optimal condition followed the Langmuir-Hinshelwood first order reaction with k=0.0095 min-1 with R2=0.9455. Complete photocatalytic degradation of ethylene dichloride was achieved after 360 min. Based on the results, it may be argued that the designed and constructed photocatalytic reactor has the potential for industrialization.
APHA. 2012. Standard methods for the examination of water and wastewater,American Public Health Association, USA.
Boukha, Z., González-Prior, J., De Rivas, B., González-Velasco, J. R., López-Fonseca, R. & Gutiérrez-Ortiz, J. I. 2018. Pd supported catalyst for gas-phase 1, 2-dichloroethane abatement: efficiency and high selectivity towards oxygenated products. Journal of Industrial and Engineering Chemistry, 57, 77-88.
Chen, D., Li, F. & Ray, A. K. 2001. External and internal mass transfer effect on photocatalytic degradation. Catalysis Today, 66, 475-485.
Choi, W., Ko, J. Y., Park, H. & Chung, J. S. 2001. Investigation on TiO2-coated optical fibers for gas-phase photocatalytic oxidation of acetone. Applied Catalysis B: Environmental, 31, 209-220.
Daneshvar, N., Salari, D. & Khataee, A. 2003. Photocatalytic degradation of azo dye acid red 14 in water: investigation of the effect of operational parameters. Journal of Photochemistry and Photobiology A: Chemistry, 157, 111-116.
Eydivand, S. & Nikazar, M. 2015. Degradation of 1, 2-Dichloroethane in simulated wastewater solution: a comprehensive study by photocatalysis using TiO2 and ZnO nanoparticles. Chemical Engineering Communications, 202, 102-111.
Fathinia, M., Khataee, A., Zarei, M. & Aber, S. 2010. Comparative photocatalytic degradation of two dyes on immobilized TiO2 nanoparticles: effect of dye molecular structure and response surface approach. Journal of Molecular Catalysis A: Chemical, 333, 73-84.
Habibi, M. H., Hassanzadeh, A. & Mahdavi, S. 2005. The effect of operational parameters on the photocatalytic degradation of three textile azo dyes in aqueous TiO2 suspensions. Journal of Photochemistry and Photobiology A: Chemistry, 172, 89-96.
Hung, W.-C., Chen, Y.-C., Chu, H. & Tseng, T.-K. 2008. Synthesis and characterization of TiO2 and Fe/TiO2 nanoparticles and their performance for photocatalytic degradation of 1, 2-dichloroethane. Applied Surface Science, 255, 2205-2213.
Jinzhang, G., Shengying, L., Wu, Y., Guohu, Z., Lili, B. & Li, S. 2007. Preparation and photocatalytic activity of PANI/TiO2 composite film. Rare Metals, 26, 1-7.
Konstantinou, I. K. & Albanis, T. A. 2004. TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations: a review. Applied Catalysis B: Environmental, 49, 1-14.
Lin, Y.-H., Chou, S.-H. & Chu, H. 2014a. A kinetic study for the degradation of 1, 2-dichloroethane by S-doped TiO2 under visible light. Journal of Nanoparticle Research, 16, 2539.
Lin, Y.-H., Hung, W.-C., Chen, Y.-C. & Chu, H. 2014b. Photocatalytic degradation of 1, 2-dichloroethane by V/TiO2: the mechanism of photocatalytic reaction and byproduct. Aerosol and Air Quality Research, 14, 280-292.
Martínez, C., Fernández, M., Santaballa, J. & Faria, J. 2011. Kinetics and mechanism of aqueous degradation of carbamazepine by heterogeneous photocatalysis using nanocrystalline TiO2, ZnO and multi-walled carbon nanotubes–anatase composites. Applied Catalysis B: Environmental, 102, 563-571.
Mohammadi, M. & Sabbaghi, S. 2014. Photo-catalytic degradation of 2, 4-DCP wastewater using MWCNT/TiO2 nano-composite activated by UV and solar light. Environmental Nanotechnology, Monitoring and Management, 1, 24-29.
Mohammadikish, M., Davar, F., Loghman-Estarki, M. R. & Hamidi, Z. 2013. Synthesis and characterization of hierarchical ZnS architectures based nanoparticles in the presence of thioglycolic acid. Ceramics International, 39, 3173-3181.
Nguyen-phan, T.-D., Pham, V. H., Shin, E. W., Pham, H.-D., Kim, S., Chung, J. S., et al. 2011. The role of graphene oxide content on the adsorption-enhanced photocatalysis of titanium dioxide/graphene oxide composites. Chemical Engineering Journal, 170, 226-232.
Sakkas, V. A., Islam, M. A., Stalikas, C & Albanis, T. A. 2010. Photocatalytic degradation using design of experiments: a review and example of the Congo red degradation. Journal of Hazardous Materials, 175, 33-44.
Soltani, N., Saion, E., Yunus, W. M. M., Erfani, M., Navasery, M., Bahmanrokh, G. et al. 2014. Enhancement of visible light photocatalytic activity of ZnS and CdS nanoparticles based on organic and inorganic coating. Applied Surface Science, 290, 440-447.
Yang, C., Dong, W., Cui, G., Zhao, Y., Shi, X., Xia, X., Tang, B. et al. 2017. Enhanced photocatalytic activity of Pani/TiO2 due to their photosensitization-synergetic effect. Electrochimica Acta, 247, 486-495.
Yu, J., Pang, Z., Zheng, C., Zhou, T., Zhang, J., Zhou, H. et al. 2019. Cotton fabric finished by PANI/TiO2 with multifunctions of conductivity, anti-ultraviolet and photocatalysis activity. Applied Surface Science, 470, 84-90.
Zhou, T., Ma, L., Gan, M., Wang, H. & Hao, C. 2019. Sandwich-structured hybrids: a facile electrostatic self-assembly of exfoliated titania nanosheets and polyaniline nanoparticles and its high visible-light photocatalytic performance. Journal of Physics and Chemistry of Solids, 125, 123-130.