Efficacy of Mn-doped ZnO towards Removal of Congo Red Dye under UV Exposure: Isotherm, Kinetics, Thermodynamics and Optimization Study

Document Type : Original Research Paper


1 Environmental Chemistry Laboratory, Department of Environmental Science, The University of Burdwan, Burdwan, West Bengal, India

2 Department of Physics, The University of Burdwan, Burdwan, West Bengal, India



Discharge of synthetic dyes from industries without treatment leads to major environmental problems. Present research highlighted the Mn-doped ZnO along with UV-induced photo degradation of Congo red (CR) dye through batch study. The synthesized Mn-doped ZnO (MDZO) was characterized by Transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). The results revealed that MDZO along with UV exposure degraded the CR dye up to 99.3% at concentration 4 mg/L, pH (7), adsorbent dose (0.6 g/L) and contact time (30 min). The degradation data nicely fitted with pseudo-secondary kinetics and the thermodynamic study suggest the said reaction is exothermic in nature. A statistical method, central composite design (CCD) was used to screen out the optimized condition of dye degradation. The interactions of main factors and optimal conditions were also evaluated by 3D surface plots. The statistical output clearly demonstrates that the dye degradation data is nicely fitted with very high goodness of fit and F value (86.19). Present research clearly suggested that Mn-doped ZnO along with UV could be an effective treatment towards degradation of Congo red dye.


Abdellah, M.H., Nosier, S.A., El-Shazly, A.H. and Mubarak, A.A. (2018). Photocatalytic decolorization of methylene blue using TiO2/UV system enhanced by air sparging. Alex. Eng. J. 57(4), 3727-3735, https://doi.org/10.1016/j.aej.2018.07.018
Abdollahi, T. Abdullah, A.H., Zainal, Z. and Yusof, N.A. (2012). Photocatalytic Degradation of p-Cresol    by Zinc Oxide under UV Irradiation, Int. J. Mol. Sci. 13,  302-315.
Achmad, A., Kassim, J., Suan, T.K., Amat, R.C., and Seey, T.L. (2012). Equilibrium, Kinetic and Thermodynamic Studies on the Adsorption of Direct Dye onto a Novel Green Adsorbent Developed from Uncaria Gambir Extract. J. Phys. Sci. 23, 1–13.
Ahmad, M. and Alrozi, R. (2011). Removal of malachite green dye from aqueous solution using rambutan peel based activated carbon: Equilibrium, kinetic and thermodynamic studies. Chem. Eng. J. 171, 510–516.
Akar, S.T. and Özcan, A.S. (2009). Biosorption of a reactive textile dye from aqueous solutions utilizing an agro-waste. Desalination 249, 757–761.
Allen, J.S., Koumanova, B. (2005). Decolourisation of water/waste water using adsorption,    J. univers. Technol. Metal. 40(3), 175-192.
Andreozzi, R., Caprio, V., Insola, A., and Marott, R. (1999). Advanced oxidation processes (AOP) for water purification and recovery. Catal. Today 53, 51–59.
Arslan, I., Balcioglu, I.A., Tuhkanen, T., and Bahnemann, D. (2000). H2O2/UV-C and Fe2+/H2O2/UV-C versus TiO2/UV A treatment for reactive dye wastewater. J. Environ. Eng. 903-11.
Bhad, R.M., Das, A., and Kodape, S.M. (2022) Ozonation of Procion Blue Reactive Dye and its Kinetics Study. Pollution 2022, 8(2): 529-541 DOI: 10.22059/POLL.2021.330871.1191
Bilicia, Z., Işık, Z., Aktaş, Y., Yatmaz, H.C. and Dizge, N. (2019). Photocatalytic effect of zinc oxide and magnetite entrapped calcium alginate beads for azo dye and hexavalent chromium removal from solutions, J. Water Process Eng. 31, 100826.
Bruno, C.B.S. and Antoninho, V. (2019). Evaluation of the photocatalytic activity of SiO2@TiO2 hybrid 
spheres in the degradation of methylene blue and hydroxylation of benezene: Kinetic and Mechanistic Study. Braz. J. Chem. Eng. 36, 1501–1518. doi: 10.1590/0104-6632.20190364s20190139.
Chattoraj, S., Mondal, N.K., Sadhukhan, B., Roy, P. and Roy, T.K. (2016). Optimization of Adsorption Parameters for Removal of Carbaryl Insecticide Using Neem Bark Dust by Response Surface Methodology. Water Conserv. Sci. Eng. 1, 127–141.
Cho, I.H. and Zoh, K.D. (2007). Photocatalytic degradation of azo dye (Reactive Red 120) in TiO2/UV system: Optimization and modeling using a response surface    methodology (RSM) based on the central composite design, Dyes Pigments 75, 533–543.
Chowdhury, S., Chakraborty, S., Saha, P.D. and (2013). Response surface optimization of a dynamic dye adsorption process: a case study of crystal violet adsorption onto NaOH- modified rice husk. Environ. Sci. Pollut. Res. 20, 1698–1705.
Chowdhury, S., and Saha, P. (2010). Sea shell powder as a new adsorbent to remove Basic Green 4  (Malachite Green) from aqueous solutions: equilibrium, kinetic and thermodynamic studies. Chem. Eng. J. 164, 168–177.
 Correia, F.V.,   Moreira, J.C. 2015.  Solar CPC Pilot Plant Photocatalytic Degradation of Indigo Carmine Dye in Waters and Wastewaters Using Supported-TiO2: Influence of Photodegradation Parameters. Int. J. Photoenergy http://dxdoiorg/101155/2015/656153.
Das, B., Mondal, N.K., Bhaumik, R. and Roy, P. (2013). Insight into adsorption equilibrium, kinetics and thermodynamics of lead onto alluvial soil. Int. J. Environ. Sci. Technol. 73, 305-310.
Das, C., Das, A. and Golder, A.K. (2016) Optimality in Microwave-Assisted Drying of Aloe Vera (Aloe barbadensis Miller) Gel using Response Surface Methodology and Artificial Neural Network Modeling. J. Inst. Eng. India Ser. E (July–December 2016) 97(2):143–149 DOI 10.1007/s40034-016-0083-7
Das, A., Golder, A.K. and Das, C. (2015) Enhanced extraction of rebaudioside-A: Experimental, response 
surface optimization and prediction using artificial neural network. Ind. Crops Prod. 65:415-421. https://doi.org/10.1016/j.indcrop.2014.11.006
Daneshvar, N., Salari, D. Khataee, A.R. (2004). Photocatalytic Degradation of Azo Dye    Acid Red 14 in Water on ZnO as an Alternative Catalyst to TiO2. J Photochem Photobiol A: Chem 162, 317-322.
Demirbas, A. (2009). Agricultural based activated carbons for the removal of dyes from aqueous solutions. J. Hazard. Mater. 167(1-3), 1-9.
Degen, A. and Kosec, M. (2000), Effect of pH and impurities on the surface charge of zinc oxide in aqueous solution, J. Eur. Ceram. Soc. 20, 667–673.
Dindar, B. and Içli, S. (2001). Unusual photoreactivity of zinc oxide irradiated by concentrated sunlight, Photochem. Photobiol. A:Chem. 140, 263–268.
Daneshvar, N., Aber, S., Seyed, D.M.S., Khataee, A.R. and Rasoulifard, M.H. (2007). Photocatalytic degradation of the insecticide diazinon in the presence of prepared nanocrystalline ZnO powders under irradiation of UV-C light. Sep. Puri. Technol. 58 (2007) 91–98.
Eyasu, A., Yadav, O.P. and Bachheti, R.K. (2013). Photocatalytic Degradation of Methyl Orange Dye    using Cr-doped ZnS Nanoparticles under Visible Radiation, Int. J.    Chem. Tech. Res. 5(4), 1452-1461.
Feng, L., Qin, Z., Huang, Y., Peng, K., Wang, F., Yan, Y. and Chen, Y. (2020). Boron-, sulfur-, and phosphorus-doped graphene for environmental applications. Sci. Total Environ. 698, 134239. https://doi.org/10.1016/j.scitotenv.2019.134239
GoUVêa, C.A.K, Wypych, F., Moraes, S.G., Durán, N. and Peralta-Zamora, P. Semiconductor assisted photocatalytic degradation of reactive dyes in aqueous solution, Chemosphere 40, 433–440.
Goncalves, M.S.T., Oliveira-Compos, A.M.F., Pinto, E.M.M.S., Plasencia, P.M.S. and Queiroz, M.J.R.P. (1999) Photochemical treatment of solutions of azo dyes containing TiO2. Chemosphere 39, 78. 
Ivanova, T. Harizanova, A., Koutzarova, T., and Vertruyen, B. (2010). Study of ZnO solgel films: Study of ZnO solgel films: Effect of annealing, Materials Letters 64, 1147.
Joseph, B. Manoj, P.K. and Vaidyan, V.K.(2005). Studies on preparation and characterization of indium doped zinc oxide films by  chemical spray deposition, Bull. Mater. Sci. 28(5), 487–493. 
Karunakaran, C., Karuthapandian, S. and Vinayagamoorthy, P. (2015). Photoinduced oxidative transformation of diphenylamine on Al2O3 with enhancement by ZnO synergism. Karbala Int. J. Modern Sci. 1, 32-38.
Kartal, O.E., Erol, M. and Oğuz, H. (2001). Photocatalytic destruction of phenol by TiO2 powders, Chem. Eng. Technol. 24, 645–649.
Kumar, M.P.S., Phanikumar, B.R. 2013. Response surface modelling of Cr6+ adsorption from aqueous solution by neem bark powder: Box–Behnken experimental approach. Environ. Sci. Pollut. Res. 20, 1327–1343.
Khan, Z.R., Khan, M.S., Zulfequar, M. and Khan M.S. (2011). Optical and Structural Properties of ZnO Thin Films fabricated by Sol-Gel Method. Materials Sciences and Applications 2, 340-345.
Khodja, A.A., Sehili, T., Pilichowski, J.F. and Boule, P. (2001). Photocatalytic degradation of 2-    phenylphenol on TiO2 and ZnO in aqueous suspensions, Photochem. Photobiol. A: Chem. 141, 231–239. 
Kamalasanan, M.N. and Chandra, S. (1996). Sol-gel synthesis of ZnO thin films. Thin Solid Films 288, 112.
Kiran, I., Ilhan, S., Caner, N., Iscen, C.F., and Yildiz, Z. (2009). Biosorption properties of dried Neurospora crassa for the removal of Burazol Blue ED dye, Desalination 249, 273-278.
Korbahti, B.K., Rauf, M.A. 2008. Response surface methodology (RSM) analysis of photoinduced decoloration of toludine blue. Chem. Eng. J. 136, 25–30.
Lizama, C., Freer, J., Baeza, J. and Mansilla, H.D. (2002). Optimized photodegradation of Reactive Blue 19 on TiO2 and ZnO suspensions, Catal. Today 76, 235–246.
Lee, K.M., and Abd Hamid, S.B. (2015). Simple Response Surface Methodology: Investigation on Advance Photocatalytic Oxidation of 4-Chlorophenoxyacetic Acid Using UV-Active ZnO Photocatalyst, Materials 8 (2015) 339-354.
Lim, Y.P. and Lim, Y.C. (2019). Synthesis of Hybrid Cu-Doped TiO2 Photocatalyst for Dye Removal. Key Eng. Mater. 797:84-91. https://doi.org/10.4028/www.scientific.net/KEM.797.84
Lin, Y., Ferronato, C., Deng, N., Wu, F. and Chovelon, J.M. (2009). Photo catalytic degradation of methylparaben by TiO2: Multivariable experimental design and  mechanism, Appl. Catal. Environ, 88, 32–41.
Milenova, I., Stambolova, V., Blaskov, A., Eliyas, S., and Vassilev, M. (2013). The effect of introducing copper dopant on the photocatalytic activity of ZnO nanoparticles. J. Chem. Technol. Metall. 48(3), 259-26.    
Mongkolserm, P., and Pabchanda, S. (2012). Influence of Tin Doping on the Photocatalytic Activity of Zinc Oxide Thin Films under UV Light, J. Chem. Chem. Eng. 6, 631-  637.
Montgomery, D.C. (2008). Design and analysis of experiments United States, New York: John Wiley & Sons Inc.
Mondal, S., and Mitra, P. (2012). Preparation of cadmium-doped ZnO thin film by SILAR and their characterization, Bull. Mater. Sci. 35(5), 751–757.
Mondal, S., Bhattacharyya, S.R. and Mitra, P. (2013). Preparation of manganese-doped ZnO thin films and their characterization, Bull. Mater. Sci. 36, 223–229.
Mrowetz, M. and Selli, E. (2006). Photocatalytic degradation of formic and benzoic acids and hydrogen peroxide evolution in TiO2 and ZnO water suspensions Photochem Photobiol A: Chem 180, 15–22.
Mahmoodi, N.M. and Arami, M. (2006). Carbon-supported iridium catalysts in the catalytic wet air oxidation of carboxylic acids:kinetics and mechanistic interpretation, Photochem. Photobiol. A: Chem. 182, 60–66.
Muruganandham, M. and Swaminathan, M. (2006). Photocatalytic decolourisation and degradation    of Reactive Orange 4 by TiO2-UV process, Dyes Pigm. 68, 133–142.
Musial, J., Mlynarczyk, D.T. and Stanisz, B.J. (2022) Photocatalytic degradation of sulfamethoxazole using TiO2-based materials – Perspectives for the development of a sustainable water treatment technology. Science of The Total Environment, 159122, https://doi.org/10.1016/j.scitotenv.2022.159122.
Malik, R., Ramteke, D.S. and Wate, S.R. (2007) Adsorption of malachite green on groundnut shell waste based powdered activated carbon. Waste Manage. 27, 1129-1138.
 Maiti, A., Basu, J.K., and De, S. (2012). Experimental and kinetic modeling of As(V) and    As(III)  adsorption on treated laterite using synthetic and contaminated groundwater: effects of phosphate, silicate and carbonate ions. Chem. Eng. J. 191, 1–12.
Montgomery, D.C. 1996. Design and Analysis of Experiments, fourth ed John Wiley and Sons USA. 
Myers, R.H., Montgomery, D.C. 2002. Response Surface Methodology, Process and Product Optimization Using Designed Experiments 2nd ed New York: John Wiley & Sons.
Nikazara, M., Golivand, K. and Mohanpoor, K. (2007). Using TiO2 supported on Clinoptilolite as a catalyst for photocatalytic degradation of azo dye Disperse yellow 23 in water. Kinet Catal 48(2), 214–220.
Pakdel, A. Ghodsi, F.E. (2011). Influence of drying conditions on the optical and structural properties of sol-gel derived ZnO nanocrystalline films. Pramana-J Phys 76, 973.
Rekha, K., Nirmala, M., Nair, M. and Anukaliani, A. (2010). Structural optical photocatalytic and antibacterial activity of zinc oxide and manganese doped zinc oxide nanoparticles, Physica. B: Condensed. Matter. 405, 3180–3185.
Roy, T.K. and Mondal, N.K. (2014). Photocatalytic degradation of Congo red dye on thermally activated zinc oxide, Int. J. Sci. Res. Env. Sci. 2(12), 457-469.
Roy, P., Mondal, N.K., Bhattacharya, S., Das, B., and Das, K. (2013). Removal of arsenic (III) and Arsenic (V) on chemically modified low-cost adsorbent: batch and column operations. Appl. Water. Sci. 3, 293–309.
Rafiq, A., Imran, M.,  Aqeel, M., Naz, M., Ikram, M. and Ali, S. (2019). Study of Transition Metal Ion Doped CdS Nanoparticles for Removal of Dye from Textile Wastewater. J. Inorg. Organomet. Poly. Mater. https://doi.org/10.1007/s10904-019-01343-5
Ristov, M., Sinadinovski, G.J., Grozdanov, I. and Mitreski, M. (1987). Chemical deposition of ZnO films Thin Solid Films 149, 65-71.    
Saggioro, E.M., Oliveira, A.S., Pavesi, T.,  Tototzintle, M.J., Maldonado, M.I., Samara, F., Jermani, E. and Kanan, S.M. (2014). Photocatalytic UV-degradation of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) in the presence of silver doped zeolite, Arabian J. Chem. 2014 http://dxdoiorg/101016/jarabjc201412009.
Sadia, M., Naz, R., Khan, J., Zahoor, M., Ullah, R., Khan, R., Naz, S., Almoallim, H.S. and Alharbi, S.A. (2021). Metal doped titania nanoparticles as efficient photocatalyst for dyes degradation. J. King Saud Uni. – Sci. 33, 101312. https://doi.org/10.1016/j.jksus.2020.101312
Swarnalatha, B. and Anjaneyulu, Y. (2004). Studies on the heterogeneous photocatalytic oxidation of 2,6-dinitrophenol in aqueous TiO2 suspension, J. Mol. Catal. A Chem.  223, 161–165.
S.Sakthivel, B.Neppolian, M.V.Shankar, B. Arabindoo, M. Palanichamy, V.Murugesan, Solar photocatalytic degradation of azo dye: comparison of photocatalytic efficiency of ZnO and TiO2. Solar Energ. Mater. Solar Cells 77 (2003) 65–82.
Shankar, M.V., Cheralathan, K.K. Arabindoo, B., Palanichamy, M. and Murugesan, V. (2004).    Enhanced photocatalytic activity for the destruction of monocrotophos pesticide by TiO2 /Hβ, J. Mol. Catal. A: chem. 223, 195-200.
Saqib, A.N.S., Waseem, A., Khan, A.F., Mahmood, Q. Khan, A., Habib, A., A.R. Kha  Arsenic bioremediation by low cost materials derived from Blue Pine (Pinus wallichiana) and Walnut (Juglans regia), Ecol. Eng. 51 (2013) 88–94.
Sokker, H.H., El-Sawy, N.M., Hassan, M.A., El-Anadouli, B.F. 2011. Adsorption of crude oil from aqueous solution by hydrogel of chitosan based polyacrylamide prepared by radiation induced graft polymerization. J. Hazard. Mater. 190, 359–365.
Sakkas, V., Calza, P., Islam, M.A., Medana, C., Baiocchi, C., Panagiotou, K. and  Albanis, T. (2009).  TiO2/H2O2 mediated photo catalytic transformation of UV filter 4-    methylbenzylidene camphor (4-MBC) in aqueous phase: Statistical optimization and photoproduct analysis, Appl. Catal. Environ. 90, 526–534.
Sadhukhan, B., Mondal, N.K. and Chattoraj, S. (2016). Optimisation using central composite design (CCD) and thedesirability function for sorption of methylene blue from aqueous solution onto Lemna major, Karbala Int. J. Modern Sci. 2, 145- 155.
Stat-Ease Inc USA Design Expert Software Educational Version 703 Published by John Wiley and Sons Ltd (2007-03-30), (2009) ISBN 10: 0470167696 / ISBN 13: 9780470167694
Sadia, M., Naz, R., Khan, J., Zahoor, M., Ullah, R., Khan, R., Naz, S., Almoallim, H.S., Ali, S., and Alharbi (2021) Metal doped titania nanoparticles as efficient photocatalyst for dyes degradation. Journal of King Saud University – Science 33(2), 101312, https://doi.org/10.1016/j.jksus.2020.101312.
Saha, P., Chowdhury, S., Gupta, S. and Kumar, I. (2010). Insight into adsorption equilibrium,  kinetics and thermodynamics of malachite green onto clayey soil of Indian origin. Chem. Eng. J. 165, 874–882.
Singh, S.N., Mishra, S., and Jauhari, N. (2015). Degradation of Anthroquinone Dyes Stimulated by Fungi. Env. Sci. Eng. DOI 101007/978-3-319-10942-8_15.
Sohrabi, M.R., Moghri, M., Masoumi, H.R.F., Amiri, S. and Moosavi, N. (2014). Optimization  of Reactive Blue 21 removal by nanoscale zerovalent iron using Optimization response surface methodology, Arabian J. chem. (2014) http://dxdoiorg/101016/jarabjc201411060
Sin, J.C., Lam, S.M. and Mohamed, A.R. (2011). Optimizing photo catalytic degradation of phenol by TiO2/GAC using response surface methodology, Korean J. Chem. Eng. 28, 84–92.
Stock, N., Peller, J., Vinodgopal, K. and Kamat, P.V. (2000). Combinative sonolysis and photocatalysis for textile dye degradation. Environ. Sci. Technol. 34, 1747.
Unal, B.O., Bilici, Z., Ugur, N., Isik, Z., Harputlu, E., Ocakoglu, K. and Dizge, N. (2019). Adsorption and Fenton oxidation of azo dyes by magnetite nanoparticles deposited on a glass substrate. J. Water Process Eng. 32, 100897.
Vijayakumar, G., Tamilarasan, R., Dharmendirakumar, M. 2012. Adsorption, Kinetic, Equilibrium and Thermodynamic studies on the removal of basic dye Rhodamine-B from aqueous solution by the use of natural adsorbent perlite. J. Mater. Environ. Sci. 3(1), 157-170. 
Wang, J., Yang, J., Li, X., Wang, D., Wei, B., Song, H., Li, X. and Fu, S. (2016). Preparation and photocatalytic properties of magnetically reusable Fe3O4@ZnO core/shell nanoparticles, Phys. E Low-Dimensional Syst. Nanostruct. (2016), https://doi.org/10.1016/j.physe.2015.08.040.
Weissmann, S., and McMurdie, H.F. (1990). Joint Committee on Powder Diffraction standards International Centre for Diffraction Data, Swarthmore PA, Inorganic Post B. 36-1451. Yeber, M.C., Soto, C., Riveros, R., Navarrete, J., and Vidal, G. (2009). Optimization by factorial 
design of copper (II) and toxicity removal using a photo catalytic process    with TiO2 as semiconductor, Chem. Eng. J. 152, 14–19. 
Yang, Z., Ye, Z., Xu, Z. and Zhao, B.H. (2009). Effect of the Morphology on the Optical Properties of ZnO Nanostructured, Physica E 42, 116.