Abstract    The aim of this research was to evaluate the effective parameters such as pH, current density (mA/cm2), H2O2/Fe2+ molar ratio, volume ratio of H2O2 to pharmaceutical wastewater (PhW) (ml/l) and reaction time (min) on the electro-Fenton process for the ibuprofen (as a pharmaceutical waste in water) removal. Since a synthetic wastewater with the same concentration of ibuprofen in a real pharmaceutical wastewater (400 ppm) was chosen in this research, the sample was tested in terms of the chemical oxygen demand (COD). The parameters were statistically optimized under response surface mythology (RSM). The software was also applied to minimize the number of runs. The optimum conditions for 98.290% COD removal were at pH of 2.43, current density of 23.08 mA/cm2, H2O2/Fe2+ molar ratio of 2.69, volume ratio of H2O2/PhW of 1.84 ml/l and reaction time of 28.08 min.

Keywords    COD, Electro-Fenton, Pharmaceutical wastewater, Treatment

چکیده    هدف از انجام این پژوهش بررسی پنج پارامتر در فرایند الکتروفنتون در حذف بروفن از یک پساب دارویی است. این پارامترها pH ، چگالی جریان، نسبت مولیH2O2/Fe2+ و نسبت حجمی H2O2/PhW (ml/l) و زمان واکنش هستند. در این تحقیق یک پساب سنتزی دست­ساخت با همان غلظت ایبوبروفن در پساب واقعی ppm)400( انتخاب شد. نمونه­ها بر اساس نیاز به اکسیژن شیمیایی (COD ) آزمایش شدند. پارامترها تحت روش سطح پاسخ (RSM) بهینه­سازی شدند. استفاده از این روش تعداد آزمایش­ها را به حداقل ‌رساند. شرایط بهینه برای حذف 29/98٪ COD در آزمایشگاه تحت شرایط pH 43/2، چگالی جریان mA/cm2 08/23، نسبت مولی H2O2/Fe2+ 69/2، نسبت حجمی H2O2/PhW(ml/l)84/1 و زمان واکنش 08/28 دقیقه به دست آمد.

References    1.      Skoumal, M., Rodriguez, R.M., Cabot, P.L., Centellas, F., Garrido, J.A., Arias, C. and Brillas, E., "Electro-fenton, uva photoelectro-fenton and solar photoelectro-fenton degradation of the drug ibuprofen in acid aqueous medium using platinum and boron-doped diamond anodes", Electrochimica Acta,  Vol. 54, No. 7, (2009), 2077-2085. 2.      Brown, J., Paxeus, N., Forlin, L. and Larsson, D., "Plasma levels of non-steroidal anti-inflammatory drugs (NSAIDS) and gemfibrozil in fish exposed to sewage effluents: Assessing the risk of discharges to aquatic environments",  (2007). 3.      Balcıoglu, I.A. and Otker, M., "Treatment of pharmaceutical wastewater containing antibiotics by O3 and O3/H2O2 processes", Chemosphere,  Vol. 50, No. 1, (2003), 85-95. 4.      Joss, A., Zabczynski, S., Gobel, A., Hoffmann, B., Loffler, D., McArdell, C.S., Ternes, T.A., Thomsen, A. and Siegrist, H., "Biological degradation of pharmaceuticals in municipal wastewater treatment: Proposing a classification scheme", Water Research,  Vol. 40, No. 8, (2006), 1686-1696. 5.      Chelliapan, S., Wilby, T. and Sallis, P.J., "Performance of an up-flow anaerobic stage reactor (UASR) in the treatment of pharmaceutical wastewater containing macrolide antibiotics", Water Research,  Vol. 40, No. 3, (2006), 507-516. 6.      Kimura, K., Hara, H. and Watanabe, Y., "Removal of pharmaceutical compounds by submerged membrane bioreactors (MBRS)", Desalination,  Vol. 178, No. 1-3, (2005), 135-140. 7.      Kosutic, K., Dolar, D., Asperger, D. and Kunst, B., "Removal of antibiotics from a model wastewater by RO/NF membranes", Separation and Purification Technology,  Vol. 53, No. 3, (2007), 244-249. 8.      Snyder, S.A., Adham, S., Redding, A.M., Cannon, F.S., DeCarolis, J., Oppenheimer, J., Wert, E.C. and Yoon, Y., "Role of membranes and activated carbon in the removal of endocrine disruptors and pharmaceuticals", Desalination,  Vol. 202, No. 1-3, (2007), 156-181. 9.      Davarnejad, R. and Sahraei, A., "Industrial wastewater treatment using an electrochemical technique: An optimized process", Desalination and Water Treatment,  Vol. 57, No. 21, (2016), 9622-9634. 10.    Thirugnanasambandham, K., Sivakumar, V. and Maran, J.P., "Application of chitosan as an adsorbent to treat rice mill wastewater—mechanism, modelling and optimization", Carbohydrate Polymers,  Vol. 97, No. 2, (2013), 451-457. 11.    Paramo-Vargas, J., Camargo, A.M.E., Gutierrez-Granados, S., Godinez, L.A. and Peralta-Hernandez, J.M., "Applying electro-fenton process as an alternative to a slaughterhouse effluent treatment", Journal of Electroanalytical Chemistry,  Vol. 754, No., (2015), 80-86. 12.    Mert, B.K., Yonar, T., Kilic, M.Y. and Kestioglu, K., "Pre-treatment studies on olive oil mill effluent using physicochemical, fenton and fenton-like oxidations processes", Journal of Hazardous Materials,  Vol. 174, No. 1, (2010), 122-128. 13.    Brillas, E., Mur, E., Sauleda, R., Sanchez, L., Peral, J., Domènech, X. and Casado, J., "Aniline mineralization by aop's: Anodic oxidation, photocatalysis, electro-fenton and photoelectro-fenton processes", Applied Catalysis B: Environmental,  Vol. 16, No. 1, (1998), 31-42. 14.    Zhang, H., Choi, H.J. and Huang, C.-P., "Optimization of fenton process for the treatment of landfill leachate", Journal of Hazardous Materials,  Vol. 125, No. 1, (2005), 166-174. 15.    Illés, E., Takács, E., Dombi, A., Gajda-Schrantz, K., Rácz, G., Gonter, K. and Wojnárovits, L., "Hydroxyl radical induced degradation of ibuprofen", Science of the Total Environment,  Vol. 447, No., (2013), 286-292. 16.    Scheytt, T., Mersmann, P., Lindstädt, R. and Heberer, T., "Determination of sorption coefficients of pharmaceutically active substances carbamazepine, diclofenac, and ibuprofen, in sandy sediments", Chemosphere,  Vol. 60, No. 2, (2005), 245-253. 17.    Davarnejad, R. and Hosseinitabar, P., "Application of iron electrode in textile industry wastewater treatment using electro-fenton technique: Experimental and statistical study", International Journal of Engineering-Transactions A: Basics,  Vol. 29, No. 7, (2016), 887-895. 18.    Suárez-Escobar, A., Pataquiva-Mateus, A. and Lopez-Vasquez, A., "Electrocoagulation—photocatalytic process for the treatment of lithographic wastewater. Optimization using response surface methodology (RSM) and kinetic study", Catalysis Today,  Vol. 266, (2016), 120-125. 19.    Davarnejad, R. and Nikseresht, M., "Dairy wastewater treatment using an electrochemical method: Experimental and statistical study", Journal of Electroanalytical Chemistry,  Vol. 775, (2016), 364-373. 20.    Kabuk, H.A., İlhan, F., Avsar, Y., Kurt, U., Apaydin, O. and Gonullu, M.T., "Investigation of leachate treatment with electrocoagulation and optimization by response surface methodology", CLEAN–Soil, Air, Water,  Vol. 42, No. 5, (2014), 571-577.           21.    El-Ghenymy, A., Garcia-Segura, S., Rodriguez, R.M., Brillas, E., El Begrani, M.S. and Abdelouahid, B.A., "Optimization of the electro-fenton and solar photoelectro-fenton treatments of sulfanilic acid solutions using a pre-pilot flow plant by response surface methodology", Journal of Hazardous Materials,  Vol. 221, (2012), 288-297. 22.    Kushwaha, J.P., Srivastava, V.C. and Mall, I.D., "Organics removal from dairy wastewater by electrochemical treatment and residue disposal", Separation and Purification Technology,  Vol. 76, No. 2, (2010), 198-205. 23.    Davarnejad, R., Mohammadi, M. and Ismail, A.F., "Petrochemical wastewater treatment by electro-fenton process using aluminum and iron electrodes: Statistical comparison", Journal of Water Process Engineering,  Vol. 3, (2014), 18-25. 24.    Körbahti, B.K., Aktaş, N. and Tanyolaç, A., "Optimization of electrochemical treatment of industrial paint wastewater with response surface methodology", Journal of Hazardous Materials,  Vol. 148, No. 1, (2007), 83-90. 25.    Deng, Y., "Physical and oxidative removal of organics during fenton treatment of mature municipal landfill leachate", Journal of Hazardous Materials,  Vol. 146, No. 1, (2007), 334-340. 26.    Shafieiyoun, S., Ebadi, T. and Nikazar, M., "Treatment of landfill leachate by fenton process with nano sized zero valent iron particles", International Journal of Environmental Research,  Vol. 6, No. 1, (2012), 119-128. 27.    Gameel, A., Malash, G., Mubarak, A. and Hussein, M., "Treatment of spent caustic from ethylene plant using electro-fenton technique", American Journal of Environmental Engineering and Science,  Vol. 2, No. 4, (2015), 37. 28.    Moussavi, G. and Aqanaghad, M., "Performance evaluation of electro-fenton process for pretreatment and biodegradability improvement of a pesticide manufacturing plant effluent", Sustain Environ Res,  Vol. 25, (2015), 249-254. 29.    Mohajeri, S., Aziz, H.A., Isa, M.H., Zahed, M.A. and Adlan, M.N., "Statistical optimization of process parameters for landfill leachate treatment using electro-fenton technique", Journal of Hazardous Materials,  Vol. 176, No. 1, (2010), 749-758. 30.    Bensadok, K., El Hanafi, N. and Lapicque, F., "Electrochemical treatment of dairy effluent using combined al and ti/pt electrodes system", Desalination,  Vol. 280, No. 1, (2011), 244-251. 31.    Lee, H. and Shoda, M., "Removal of cod and color from livestock wastewater by the fenton method", Journal of Hazardous Materials,  Vol. 153, No. 3, (2008), 1314-1319. 32.    Méndez-Arriaga, F., Torres-Palma, R., Pétrier, C., Esplugas, S., Gimenez, J. and Pulgarin, C., "Ultrasonic treatment of water contaminated with ibuprofen", Water Research,  Vol. 42, No. 16, (2008), 4243-4248. 33.    Méndez-Arriaga, F., Maldonado, M.I., Gimenez, J., Esplugas, S. and Malato, S., "Abatement of ibuprofen by solar photocatalysis process: Enhancement and scale up", Catalysis Today,  Vol. 144, No. 1, (2009), 112-116. 34.             Mendez-Arriaga, F., Esplugas, S. and Gimenez, J., "Degradation of the emerging contaminant ibuprofen in water by photo-fenton", Water Research,  Vol. 44, No. 2, (2010), 589-595.