Taguchi Modeling for Techno-Economical Evaluation of Cr+6 Removal by Electrocoagulation Process With the Aid of Two Coagulants

Document Type : Research Papers

Authors

1 Amirkabir Uni. of Tech.

2 Amirkabir University of Technology

Abstract

The research aimed to apply the Taguchi method for techno-economical evaluation of Cr+6 removal using the electro-coagulation process with the aid of two different coagulants (FeCl3 and PAC). Taguchi orthogonal array L27 (313) was applied for analyzing the effect of four variables including initial pH, reaction time, current density and coagulant types in an attempt to improve the chromium removal efficiency. Based on the signal-to-noise ratio (S/N) and the analysis of variance (ANOVA), the results indicated that the reaction time was the most important variable on the hexavalent chromium removal efficiency. However, the current density, reaction time and coagulant types significantly influenced the operating costs. The optimum conditions for the mentioned variables were found to be an initial pH of 7, a reaction time of 60 min, a current density of 12.5 mA/cm2 and FeCl3 as a coagulant. Due to the interaction between the initial pH and coagulant type at pH 7, PAC also considered as a coagulant in this experiment. Under the mentioned conditions, the removal efficiencies of 92% and 95% were achieved using the chromium removal process by FeCl3 and PAC, respectively.

Keywords


Aber, S., Amani-Ghadim, A.R. and Mirzajani, V. (2009). "Removal of Cr(VI) from polluted solutions by electrocoagulation: Modeling of experimental results using artificial neural network", Journal of Hazardous Materials, 171(1 – 3), 484-490.
Akbal, F. and Camci, S. (2010). "Comparison of electrocoagulation and chemical coagulation for heavy metal removal", Chemical Engineering Technology, 33(10), 1655-1664.
Akbal, F. and Camci, S. (2011), "Copper, chromium and nickel removal from metal plating wastewater by electrocoagulation", Desalination, 269(1–3), 214-222.
American Public Health Association, American Water Works Association, Water Pollution Control Federation. (1998). Standard methods for the examination of water and wastewater, 20th Edition, Washington D.C.
Asadi Habib, M., Alavi Moghaddam, M.R., Arami, M. and Hashemi, H. (2012). “Optimization of the electrocoagulation process for removal of Cr+6 using Taguchi method”, Journal of Water and Wastewater, 22(80), 2-8, (In Persian).
Barrera-D´ıaz, C.E., Lugo-Lugo, V. and Bilyeu, B. (2012). "A review of chemical, electrochemical and biological methods for aqueous Cr(VI) reduction", Journal of Hazardous Materials, 223- 224 (2012), 1–12.
Bazrafshan, E., Mahvi, A.H., Nasseri, S. and Mesdaghinia, A.R. (2008). "Performance evaluation of electrocoagulation process for removal of Cr+6 from synthetic chromium solutions using iron and aluminum electrodes", Turkish Journal of Engineering Environmental Science, 32(1), 59-66.
Behbahani, M., Alavi Moghaddam, M.R. and  Arami, M. (2011). "Techno-economical evaluation of fluoride removal by electrocoagulation process: Optimization through response surface methodology", Desalination, 271(1–3), 209-218.
Bhatti, M.S., Reddy, A.S., Kalia, R.K. and Thukral, A.K. (2011). "Modeling and optimization of voltage and treatment time for electrocoagulation removal of hexavalent chromium", Desalination, 269(2–3), 157-162.
Bhatti, M.S., Reddy, A.S. and Thukral, A.K. (2009). "Electrocoagulation removal of Cr(VI) from simulated wastewater using response surface methodology", Journal of Hazardous Material, 172(1–3), 839-846.
Chafi, M., Gourich, B., Essadki, A.H., Vial, C. and Fabregat, A. (2011). "Comparison of electrocoagulation using iron and aluminium electrodes with chemical coagulation for the removal of a highly soluble acid dye", Desalination, 281(1), 285–292.
Davila, J.A., Machuca, F. and Marrianga, N. (2011). "Treatment of vinasses by electrocoagulation–electroflotation using the Taguchi method", Electrochimica Acta, 56(22), 7433– 7436.
Eary, L.E. and Dhanpat, R. (1988). "Chromate removal from aqueous wastes by reduction with ferrous ion", Environmental Science and Technology, 22(8), 972–977.
Heidmann, I. and Calmano, W. (2008), "Removal of Zn+2, Cu+2, Ni+2, Ag+1 and Cr+6 present in aqueous solutions by aluminum electrocoagulation", Journal of Hazardous Materials, 152(3), 934-941.
Irdemez, S., Yildiz, Y.S. and Tosuno˘glu, V. (2006). "Optimization of phosphate removal from wastewater by electrocoagulation with aluminum plate electrodes", Separation and Purification Technology, 52(2), 394–401.
Keles, O. (2009). "An optimization study on the cementation of silver with copper in nitrate solutions by Taguchi design", Hydrometallurgy, 95(3–4), 333–336.
Keshmirzadeh, E., Yousefi, S. and Rofouei, M.K. (2011). "An investigation on the new operational parameter effective in Cr (VI) removal efficiency: A sudy on electrocoagulation by alternating pulse current", Journal of Hazardous Materials, 190(1–3), 119-124.
Martínez-Villafa˜ne, J.F. and Montero-Ocampo, C. (2010). "Optimization of energy consumption in arsenic electro-removal from groundwater by the Taguchi method", Separation and Purification Technology, 70(3), 302–305.
Phadke, M.S. (1989).Quality Engineering Using Robust Design, Prentice Hall, New Jersey.
Roy, R.K. (1990). A Primer on the Taguchi Method, Van Nostrand Reinhold.
Secula, M.S.,  Cagnon, B., Oliveira, T.F., Chedeville, O. and  Fauduet, H. (2012). "Removal of acid dye from aqueous solutions by electrocoagulation/GAC adsorption coupling: Kinetics and electrical operating costs", Journal of the Taiwan Institute of Chemical Engineers, 43(5), 767-775.
Shafaei, A., Pajootan, E., Nikazar, M. and Arami, M. (2011). "Removal of Co+2 from aqueous solution by electrocoagulation process using aluminum electrodes", Desalination, 279(1–3), 121-126.
Yildiz, Y.S. (2008). "Optimization of Bomaplex Red CR-L dye removal from aqueous solution by electrocoagulation using aluminum electrodes", Journal of Hazardous Materials, 153(1–2), 194–200.
Yurik, T.K. and Pikaev, A.K. (1999). "Radiolysis of weakly acidic and neutral aqueous solutions of hexavalent chromium ions", High Energy Chemistry, 33(4), 208–212.
Zongo, I., Leclerc, J.P., Maïga, H.A., Wéthé, J. and Lapicque, F. (2009). "Removal of hexavalent chromium from industrial wastewater by electrocoagulation: A comprehensive comparison of aluminum and iron electrodes", Separation and Purification Technology, 66(1), 159-166.