Pharmaceutical Wastewater Chemical Oxygen Demand Reduction: Electro-Fenton, UV-enhanced Electro-Fenton and Activated Sludge

Document Type : Original Article


1 Department of Chemical Engineering, Faculty of Engineering, Arak University, Arak, Iran

2 Research Center for Environmental Determinants of Health, Kermanshah University of Medical Sciences, Kermanshah, Iran


In this study, Chemical Oxygen Demand (COD) from a pharmaceutical wastewater (PhW) was reduced by several techniques such as electro-Fenton (EF), photo electro-Fenton (PEF) and activated sludge (AS) processes and the obtained data were compared with each other. The effects of several parameters such as pH, current density, H2O2/Fe2+ molar ratio, volume ratio of H2O2/PhW, reaction time and UVA light were studied on the COD reduction through the EF and PEF processes. The Box-Behnken Design (BBD) under Response Surface Methodology (RSM) was applied to design and then optimize these processes. The optimal conditions for 87% of COD removal through the EF process were at pH of 3.27, current density of 57 mA/cm2, H2O2/Fe2+ molar ratio of 3.5, volume ratio of H2O2/PhW of 1.34 ml/l and reaction time of 56.32 min while the optimal conditions for 91.6% of COD removal through PEF process were at pH of 3.5, current density of 57.5 mA/cm2, H2O2/Fe2+ molar ratio of 3.81, volume ratio of H2O2/PhW of 1.5 ml/l, reaction time of 10.12 min and 6 W UVA light while 77.70% of COD removal was obtained by  the AS process with residence time of 1020 min. According to the kinetic study, the second order reaction (with high R2 data) could properly model the EF and PEF processes.


1. Ganzenko, O., Oturan, N., Huguenot, D., Van Hullebusch, E.D.,
Esposito, G. and Oturan, M. A., “Removal of psychoactive
pharmaceutical caffeine from water by electro-Fenton process
using BDD anode: Effects of operating parameters on removal
efficiency”, Separation and Purification Technology, Vol. 156,
(2015), 987–995.  
2. Pomati, F., Netting, A.G., Calamari, D. and Neilan, B. A.,
“Effects of erythromycin, tetracycline and ibuprofen on the
growth of Synechocystis sp. and Lemna minor”, Aquatic
Toxicology, Vol. 67, No. 4, (2004), 387–396.  
3. Brown, J., Paxéus, 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), 1–6. 
doi: 10.13140/RG.2.1.4244.3929. 
4. Deegan, A.M., Shaik, B., Nolan, K., Urell, K., Oelgemöller, M.,
Tobin, J. and Morrissey, A., “Treatment options for wastewater
effluents from pharmaceutical companies”, International
Journal of Environmental Science & Technology, Vol. 8, No. 3,
(2011), 649–666.  
5. Wang, J. and Wang, S., “Removal of pharmaceuticals and
personal care products (PPCPs) from wastewater: a review”,
Journal of Environmental Management, Vol. 182, (2016), 620– 640.  
6. Fatta, D., Achilleos, A., Nikolaou, A. and Meric, S., “Analytical
methods for tracing pharmaceutical residues in water and
wastewater”, TrAC Trends in Analytical Chemistry, Vol. 26, No.
6, (2007), 515–533.  
7. Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M.,
Zaugg, S.D., Barber, L.B. and Buxton, H. T., “Pharmaceuticals,
hormones, and other organic wastewater contaminants in US
streams, 1999− 2000: A national reconnaissance”,
Environmental Science & Technology, Vol. 36, No. 6, (2002),
8. Verlicchi, P., Al Aukidy, M. and Zambello, E., “Occurrence of
pharmaceutical compounds in urban wastewater: removal, mass
load and environmental risk after a secondary treatment—a
review”, Science of the Total Environment, Vol. 429, (2012),
9. Plósz, B.G., Langford, K.H. and Thomas, K. V., “An activated
sludge modeling framework for xenobiotic trace chemicals
(ASM‐X): Assessment of diclofenac and carbamazepine”,
Biotechnology and Bioengineering, Vol. 109, No. 11, (2012),
10. Kaya, Y., Ersan, G., Vergili, I., Gönder, Z.B., Yilmaz, G., Dizge,
N. and Aydiner, C., “The treatment of pharmaceutical wastewater
using in a submerged membrane bioreactor under different sludge
retention times”, Journal of Membrane Science, Vol. 442,
(2013), 72–82.  
11. Chang, C.Y., Chang, J.S., Vigneswaran, S. and Kandasamy, J.,
“Pharmaceutical wastewater treatment by membrane bioreactor
process–a case study in southern Taiwan”, Desalination, Vol.
234, No. 1–3, (2008), 393–401.  
12. Santosa, I.J., Grossmana, M.J., Sartorattob, A., Ponezib, A.N. and
Durranta, L. R., “Degradation of the recalcitrant pharmaceuticals
carbamazepine and 17α-ethinylestradiol by ligninolytic fungi”,
Chemical Engineering Transactions, Vol. 27, (2012), 169–174.  
13. Khunjar, W.O., Mackintosh, S.A., Skotnicka-Pitak, J., Baik, S.,
Aga, D.S. and Love, N. G., “Elucidating the relative roles of
ammonia oxidizing and heterotrophic bacteria during the
biotransformation of 17α-ethinylestradiol and trimethoprim”,
Environmental Science & Technology, Vol. 45, No. 8, (2011),
14. Li, Y., Zhu, G., Ng, W.J. and Tan, S. K., “A review on removing
pharmaceutical contaminants from wastewater by constructed
wetlands: design, performance and mechanism”, Science of the
Total Environment, Vol. 468, (2014), 908–932.  
15. Alexander, J.T., Hai, F.I. and Al-aboud, T. M., “Chemical
coagulation-based processes for trace organic contaminant
removal: Current state and future potential”, Journal of
Environmental Management, Vol. 111, (2012), 195–207.  
16. Yuan, H. and He, Z., “Integrating membrane filtration into
bioelectrochemical systems as next generation energy-efficient
wastewater treatment technologies for water reclamation: a
review”, Bioresource Technology, Vol. 195, (2015), 202–209.  
17. Nielsen, L. and Bandosz, T. J., “Analysis of the competitive
adsorption of pharmaceuticals on waste derived materials”,
Chemical Engineering Journal, Vol. 287, (2016), 139–147.  
18. Davarnejad, R. and Sahraei, A., “Industrial wastewater treatment
using an electrochemical technique: an optimized process”,
Desalination and Water Treatment, Vol. 57, No. 21, (2016),
19. Liu, H., Li, X.Z., Leng, Y.J. and Wang, C., “Kinetic modeling of
electro-Fenton reaction in aqueous solution”, Water Research,
Vol. 41, No. 5, (2007), 1161–1167.  
20. Davarnejad, R., Zangene, K., Fazlali, A.R. and Behfar, R.,
“Ibuprofen Removal from a Pharmaceutical Wastewater using
Electro-Fenton Process: An Efficient Technique (RESEARCH
NOTE)”, International Journal of Engineering - Transaction
B: Applications, Vol. 30, No. 11, (2017), 1639–1646.  
21. 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.  
22. Davarnejad, R. and Azizi, J., “Alcoholic wastewater treatment
using electro-Fenton technique modified by Fe2O3
nanoparticles”, Journal of Environmental Chemical
Engineering, Vol. 4, No. 2, (2016), 2342–2349.  
23. Rice, E.W., Baird, R.B., Eaton, A.., Standard methods for the
examination of water and wastewater (Vol. 10), Washington, DC:
American Public Health Association, Water Environment
Federation, (2012). 
24. García, O., Isarain-Chávez, E., Garcia-Segura, S., Brillas, E. and
Peralta-Hernández, J. M., “Degradation of 2, 4dichlorophenoxyacetic acid by electro-oxidation and electro-Fenton/BDDprocessesusingapre-pilot plant”, Electrocatalysis, Vol. 4,No.4,(2013),224–234.
25. Gameel, A., Malash, G., Mubarak, A.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), 37–46.  
26. Oturan, N., Sirés, I., Oturan, M.A. and Brillas, E., “Degradation
of pesticides in aqueous medium by electro-Fenton and related
methods. A review”, Environmental Engineering and
Management Journal, Vol. 19, No. 5, (2009), 235–255.  
27. Olvera-Vargas, H., Oturan, N., Oturan, M.A. and Brillas, E.,
“Electro-Fenton and solar photoelectro-Fenton treatments of the
pharmaceutical ranitidine in pre-pilot flow plant scale”,
Separation and Purification Technology, Vol. 146, (2015), 127– 135.  
28. Cruz-González, K., Torres-Lopez, O., García-León, A.M.,
Brillas, E., Hernández-Ramírez, A. and Peralta-Hernández, J. M.,
“Optimization of electro-Fenton/BDD process for decolorization