Document Type : Original Article


1 Department of Environmental Civil Engineering, Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran

2 Department of Energy Conversion, Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran


Many pollutants in industrial wastewaters, such as dyes, can't be removed easily by the conventional physical, biological and chemical purification processes, because of their complexity and intractability. Therefore, it is necessary to find an effective treatment technology that can degrade complex bio-refractory molecules or can breakdown them into smaller molecules which can be further degraded by conventional methods. Cavitation is one such recent technique which has been extensively studied for the treatment of complex wastewater due to its ability of generating highly reactive free radicals. Hydrodynamic cavitation has a potential of application on larger scale due to its capability in generating hydroxyl radicals at ambient condition, easy scale up and less material cost making it more economical to employ. The purpose of this study was application of hydrodynamic cavitation process for removing Reactive Black 5 and optimization the affecting parameters (pH, inlet pressure, hole diameter and initial concentration of dye) based on the amount of efficiency and energy consumption.
Material and methods:
In this research, removal of Reactive Black 5 with the use of hydrodynamic cavitation process was studied. 8.25 liters of colored solution was examined in each test. The cavitation was produced by orifice plate and pump. In order to optimize process, various trials were performed in pH of 3 to 11 and also using different orifice plates with hole diameter of 2, 3, 5 and 7 mm at inlet pressures of 2, 3, 4 and 5 bar and dye concentration of 30, 50 and 100 ppm. Due to the constant voltage of urban electricity, the electric current was measured as an indicator of energy consumption by ammeter.
Results and discussion:
According to the results by reducing the pH, dye removal was increased and orifice plates with larger hole diameter in upper pressures had better efficiency. It was observed that increasing the initial concentration of dye resulted in decreasing dye removal efficiency. The orifice with 7 mm hole diameter at 5 bar inlet pressure yielded the highest efficiency, but by involving the amount of energy consumed and considering the process efficiency to energy consumption, the orifice with 7 mm hole diameter at 4 bar inlet pressure was chosen as the best. The pH of 3, orifice with 7 mm hole diameter at 4 bar pressure and initial concentration of 30 ppm (with regards to pump energy consumption obtained from measuring the electrical current and the efficiency of process) were selected as optimum conditions. In these conditions after 120 minutes, 38.21% dye removal was obtained using hydrodynamic cavitation.
Hydrodynamic cavitation has a potential of application on larger scale due to its capability in generating hydroxyl radicals at ambient condition. It was found that the energy consumption was an effective factor in selecting the optimum conditions. By reducing the initial dye concentration and pH, dye removal was increased and orifice plates with larger hole diameter in upper pressures had better efficiency.


  1. Aseev, D.G. and Batoeva, A.A., 2014. Effect of hydrodynamic cavitation on the rate of OH radical formation in the presence of hydrogen peroxide. Russian Journal of Physical Chemistry. 88(1), 28-31.
  2. Asgari, R. and Ayati, B., 2015. Using the EDTA hole scavenger to accelerate decolonization in the immobilized photocatalytic process. Journal of Water and Wastewater. 26(3), 19-27. (In Persian with English abstract).
  3. Asgari, R. and Ayati, B., 2016. Scavenger effects on accelerating photocatalytic removal of direct blue 71 dye with nano TiO2 immobilized on a cementitious bed. Sharif Civil Engineering Journal. 31(4.2), 25-35. (In Persian with English abstract).
  4. Avatefinezhad, G. and Asrari, E., 2016. Evaluation of nitrate removal from the water using eichhornia crassipes. Iran-Water Resources Research. 12(2), 141-151. (In Persian with English abstract).
  5. Bagal, M.V. and Gogate, P.R., 2014. Degradation of diclofenac sodium using combined processes based on hydrodynamic cavitation and heterogeneous photocatalysis. Ultrasonics Sonochemistry. 21(3), 1035-1043.
  6. Bis, M., Montusiewicz, A., Ozonek, J. and Pasieczna-Patkowska, S., 2015. Application of hydrodynamic cavitation to improve the biodegradability of mature landfill leachate. Ultrasonics Sonochemistry. 26, 378-387.
  7. Franco, D.S.P., Tanabe, E.H., Bertuol, D.A., Reis, G.S.D., Lima, E.C. and Dotto, G.L., 2017. Alternative treatments to improve the potential of rice husk as adsorbent for methylene blue. Water Science & Technology. 75(2), 296-305.
  8. Franke, M., Braeutigam, P., Wu, Z.L., Ren, Y. and Ondruschka, B., 2011. Enhancement of chloroform degradation by the combination of hydrodynamic and acoustic cavitation. Ultrasonics Sonochemistry. 18(4), 888-894.
  9. Gharbani, P. and Mehrizad, A., 2016. Evaluation of Ultrasound/H2O2 process efficiency in removal of Benzaldehyde from aqueous solutions. Modares Civil Engineering Journal. 16(5), 119-127. (In Persian with English abstract).
  10. Gharibzadeh, N., Fatehifar, E., Alizadeh, R., Haghlesan, A.N. and Chavoshbashi, M., 2016. Modeling and optimization of removal of toluene from aqueous solutions using iron oxide nanoparticles by RSM method. Modares Civil Engineering Journal. 16(2), 203-213. (In Persian with English abstract).
  11. Ghoneim, M.M., El-Desoky, H.S. and Zidan, N.M., 2011. Electro-fenton oxidation of sunset yellow FCF azo-dye in aqueous solutions. Desalination. 274(1), 22-30.
  12. Goel, M., Hongqiang, H., Mujumdar, A.S. and Ray, M.B., 2004. Sonochemical decomposition of volatile and non-volatile organic compounds – a comparative study. Water Research. 38(19), 4247-4261.
  13. Gogate, P.R., 2011. Hydrodynamic cavitation for food and water processing. Food and Bioprocess Technology. 4(6), 996-1011.
  14. Gogate, P.R. and Pandit, A.B., 2004. A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions. Advances in Environmental Research. 8(3-4), 501-551.
  15. Gore, M.M., Saharan, V.K., Pinjari, D.V., Chavan, P.V. and Pandit, A.B., 2014. Degradation of reactive orange 4 dye using hydrodynamic cavitation based hybrid techniques. Ultrasonics Sonochemistry. 21(3), 1075-1082.
  16. Gupta, V.K., Agarwal, S., Olgun, A., Demir, H.I., Yola, M.L. and Atar, N., 2016. Adsorptive properties of molasses modified boron enrichment waste based nanoclay for removal of basic dyes. Journal of Industrial and Engineering Chemistry. 34, 244-249.
  17. Huang, Y., Wu, Y., Huang, W., Yang, F. and Ren, X., 2013. Degradation of chitosan by hydrodynamic cavitation. Polymer Degradation and Stability. 98(1), 37-43.
  18. Krishnakumar, B. and Swaminathan, M., 2010. Solar photocatalytic degradation of acid black 1 with ZnO. Journal of Chemistry. 49, 1035-1040.
  19. Madhavan, J., Grieser, F. and Ashokkumar, M., 2010. Degradation of Orange-G by advanced oxidation processes. Ultrasonics Sonochemistry. 17(2), 338-343.
  20. Panbehkarbisheh, M. and Ayati, B., 2015. Compare the two oxidizing NaIO4 and NaBrO3 on improving the photocatalytic process by UV/TiO2 in removal of Direct Blue 71 dye. Sharif Civil Engineering Journal. 30(4.1), 57-65. (In Persian with English abstract).
  21. Papić, S., Vujević, D., Koprivanac, N. and Šinko,D., 2009. Decolourization and mineralization of commercial reactive dyes by using homogeneous and heterogeneous Fenton and UV/Fenton processes. Journal of Hazardous Materials. 164(2-3), 1137-1145.
  22. Parsa, J.B. and Zonouzian, S.A.E., 2013. Optimization of a heterogeneous catalytic hydrodynamic cavitation reactor performance in decolorization of Rhodamine B: Application of scrap iron sheets. Ultrasonics Sonochemistry. 20(6), 1442-1449.
  23. Rajoriya, S., Bargole, S. and Saharan, V.K., 2017. Degradation of a cationic dye (Rhodamine 6G) using hydrodynamic cavitation coupled with other oxidative agents: Reaction mechanism and pathway. Ultrasonics Sonochemistry. 34, 183-194.
  24. Rajoriya, S., Carpenter, J., Saharan, V.K. and Pandit, A.B., 2016. Hydrodynamic cavitation: an advanced oxidation process for the degradation of bio-refractory pollutants. Reviews in Chemical Engineering. 32(4), 379-411.
  25. Raut-Jadhav, S., Saharan, V.K., Pinjari, D., Sonawane, S., Saini, D. and Pandit, A., 2013a. Synergetic effect of combination of AOP's (hydrodynamic cavitation and H2O2) on the degradation of neonicotinoid class of insecticide. Journal of Hazardous Materials. 261, 139-147.
  26. Raut-Jadhav, S., Saharan, V.K., Pinjari, D.V., Saini, D.R., Sonawane, S.H. and Pandit, A.B., 2013b. Intensification of degradation of imidacloprid in aqueous solutions by combination of hydrodynamic cavitation with various advanced oxidation processes (AOPs). Journal of Environmental Chemical Engineering. 1(4), 850-857.
  27. Saeid-Mohammadi, A., Asgari, G., Mehralipour, J., Shabanlo, A., Almasi, H. and Zaheri, F., 2016. Sonochemical oxidation of Acid Blue 113 by Fe (II) - activated Hydrogen Peroxide and Persulfate in aqueous environment. Journal of Water & Wastewater. 27(2), 2-13. (In Persian with English abstract).
  28. Saharan, V.K., Badve, M.P. and Pandit, A.B., 2011, Degradation of Reactive Red 120 dye using hydrodynamic cavitation. Chemical Engineering Journal. 178, 100-107.
  29. Sahooa, M.K., Sinhaa, B., Marbanianga, M., Naikb, D.B. and Sharanc, R.N., 2012. Mineralization of Calcon by UV/oxidant systems and assessment of bio-toxicity of the treated solutions by E. coli colony forming unit assay. Chemical Engineering Journal. 181-182, 206-214.
  30. Sayyaadi, S., 2015. Enhanced cavitation-oxidation process of non-VOC aqueous solution using hydrodynamic cavitation reactor. Chemical Engineering Journal. 272, 79-91.
  31. Wang, M. and Yuan, W., 2016. Modeling bubble dynamics and radical kinetics in ultrasound induced microalgal cell disruption. Ultrasonics Sonochemistry. 28, 7-14.
  32. Wang, X., Jia, J. and Wang, Y., 2017. Combination of photocatalysis with hydrodynamic cavitation for degradation of tetracycline. Chemical Engineering Journal. 315, 274-282.
  33. Wong, C.P.P., Lai, C.W., Lee, K.M. and Hamid, S.B.A., 2015. Advanced chemical reduction of reduced Graphene Oxide and its photocatalytic activity in degrading Reactive Black 5. Materials. 8(10), 7118-7128.
  34. Wu, J., Zhang, H. and Qiu, J., 2012. Degradation of acid orange 7 in aqueous solution by a novel electro/Fe2+/peroxydisulfate process. Journal of Hazardous Materials. 215-216, 138-145.