Corresponding Author

Mehmet A. OTURAN(mehmet.oturan@univ-paris-est.fr)


The degradation behavior of 8-hydroxyquinoleine sulfate (8-HQS), a model molecule of quinolines, was studied in an aqueous medium by electro-Fenton process using a carbon felt cathode and a platinum anode. The great oxidation ability of this process is due to a large production of hydroxyl radical (OH) by electrochemically induced Fenton’s reagent (H2O2, Fe2+). Hydroxyl radicals are very powerful oxidizing agents which react on organics up to complete mineralization. A factorial experimental design was used for determining the operating parameters on the degradation of 8-HQS in an aqueous medium. The results showed that the current intensity and the initial concentration of 8-HQS were the main factors that influenced the degradation rate. The decay in concentration of 8-HQS with the electrolysis time shows that the oxidation of 8-HQS follows pseudo-first order kinetics. The absolute rate constant for the oxidation of 8-HQS by OH was determined by using competition kinetics method and found to be 1.62×109 mol-1·L·s-1. The optimal experimental parameters for the mineralization of 8-HQS have also been investigated by the use of Doehlert matrix. It has been demonstrated that under the optimal conditions determined by this method, electro-Fenton process can lead to a quasi-complete mineralization (95% of TOC removal) of 8-HQS aqueous solution. The treatment of 8-HQS aqueous solutions leads to the formation of short-chain carboxylic acids as end-products before mineralization. Their evolution during electro-Fenton treatment was studied. The follow-up of the solution toxicity evolution shows the formation of intermediates more toxic than 8-HQS. However, the solution toxicity was totally removed after mineralization of these intermediates.

Graphical Abstract


8-HQS, electro-Fenton process, hydroxyl radicals, degradation, Doehlert matrix, mineralization, toxicity

Publication Date


Online Available Date


Revised Date


Received Date



[1] Thomsen A B. Degradation of quinolone by wet oxidation-kinetic aspects and reaction mechanisms[J]. Water Research, 1998, 32(1): 136-146.

[2] Malmstead M J, Brockman F J, Valocchi A J, et al. Modeling biofilm biodegradation requiring co-substrates: The quinolone eXample[J]. Water Science & Technology, 1995, 31(1):71-84.

[3] Padoley K V, Mudliar S N, Pandey R A. Heterocyclic nitrogenous pollutants in the environment and their treatment options-an overview[J]. Bioresource Technology, 2008, 99(10): 4029-4043.

[4] Jianlong W, Xiangchun Q, Liping H, et al. Microbial degradation of quinoline by immobilized cells of Burkholderia pickettii. Water Research 2002, 36(9): 2288-2296.

[5] Li Y, Gu G, Zhao J, Yu H. Anoxic degradation of nitrogenous heterocyclic compounds by acclimated activated sludge[J]. Process Biochemistry, 2001, 37(1): 81-86.

[6] Li Y, Wang L, Liao L, et al. Nitrate-dependent biodegradation of quinoline, isoquinoline, and 2-methylquinoline by acclimated activated sludge[J]. Journal of Hazardous Materials, 2010, 173(1/3): 151-158.

[7] Bohlmann U, Bohnet M. Improvement of process stability of microbiological quinoline degradation in a three-phase fluidized bed reactor[J]. Chemical Engineering & Technology, 2001, 24(8): 91A-96A.

[8] Buchtmann C, Kies U, Deckwer W D, Hecht V. Performance of three phase fluidized bed reactor for quinoline degradation on various supports at steady state and dynamic conditions[J]. Biotechnology & Bioengineering, 1997, 56(3): 295-303.

[9] Brillas E, Sirés I, Oturan M A. Electro-Fenton process and related electrochemical technologies base on Fenton’s reaction chemistry[J]. Chemical Reviews, 2009, 109(12): 6570-6631.

[10] Guinea E, Garrido J A, Rodríguez R M, et al. Degradation of the fluoroquinolone enrofloxacin by electrochemical advanced oxidation processes based on hydrogen peroxide electrogeneration[J]. Electrochimica Acta. 2010, 55(6): 2101-2115.

[11] Pignatello J J, Oliveros E, MacKay A. Advanced oxidation processes for organic contaminant destruction based on the Fenton reaction and related chemistry[J]. Critical Reviews in Environmental Science & Technology, 2006, 36: 1-84.

[12] ?zcan A, ?ahin Y, Koparal S A, et al. A comparative study on the efficiency of electro-Fenton process in the removal of propham from water[J]. Applied Catalysis B: Environmental, 2009, 89(3/4): 620-626.

[13] Oturan N, Sirés I, Oturan M A, et al. Degradation of pesticides in aqueous medium by electro-Fenton and related methods[J]. A review. Journal of Environmental Engineering & Management, 2009, 19(5): 235-255.

[14] Thomsen A B, Kilen H H. Wet oxidation of quinoline: intermediates and by-product toXicity[J]. Water Research, 1998, 32(11): 3353-3361.

[15] Ogunsola O M. Decomposition of isoquinoline and quinolone by supercritical water[J]. Journal of Hazardous Materials, 2000, 74(3): 187-195.

[16] Pichat P, Cermenati L, Albini A, et al. Degradation processes of organic compounds over UV-irradiated TiO2[J]. Effect of ozone. Research on Chemical Intermediates, 2000, 26(2): 161-170.

[17] Wang X, Huang X, Zuo C, et al. Kinetics of quinoline degradation by O3/UV in aqueous phase[J]. Chemosphere, 2004, 55(5): 733-741.

[19] Trabelsi S, Bellakhal N, Oturan N, et al. Application of Doehlert matrix to determine the optimal conditions for landfill leachate treatment by electro-Fenton process[J]. Journal of Materials & Environmental Science, 2012, 3(3): 426-433.

[20] Lewis G A, Mathieu D, Phan-Tan-Luu R. Pharmaceutical experimental Design, Marcel Dekker, New York (1998).

[21] Hellal F, Dachraoui M. Application of doehlert matrix to the study of flow injection procedure for selenium (IV) determination[J]. Talanta, 2004, 63(4): 1089-1094.

[22] Goupy J. in: Techniques de l’ingénieur, Editions of T.I (ETI), vol. 4, pp. PE 230/1-PE 230/26.

[23] Oturan M A. Oturan N, Lahitte C, et al. Production of hydroxyl radicals by electrochemically assisted Fenton’s reagent. Application to the mineralization of an organic micropollutant, pentachlorophenol[J]. Journal of Electroanalytical Chemistry, 2001, 507(1/2): 96-102.

[24] Brillas E, Mur E, Sauleda R, et al. Aniline mineralization by AOP’s: anodic oxidation, photocatalysis, electro-Fenton and photoelectron-Fenton processes[J]. Applied Catalysis B: Environmental, 1998, 16(1): 31-42.

[25] Trabelsi S, Bellakhal N, Oturan N, et al. Electrochemical oxidation of phthalic anhydride in aqueous medium by electro-Fenton process[J]. Journal of Environmental Engineering & Management, 2009, 19(5): 291-297.

[26] Neyens E, Baeyens J. A review of classic Fenton’s peroxidation as an advanced oxidation technique[J]. Journal of Hazardous Materials, 2003, 98(1/3): 33-50.

[27] J. Goupy, La méthode des plans d’expériences, DUNOD, Paris (1996), pages: 9-27.

[28] Haaland D P. Experimental design in biotechnology, Marcel Dekker Inc., New York (1989).

[29] Hammami S, Oturan N, Bellakhal N, et al. Oxidative degradation of direct orange 61 by electro-Fenton process using a carbon felt electrode: Application of the experimental design methodology[J]. Journal of Electroanalytical Chemistry, 2007, 610(1): 75-84.

[30] Kesraoui Abdessalem A, Oturan N, Bellakhal N, et al. Experimental design methodology applied to electro-Fenton treatment for degradation of herbicide chlortoluron[J]. Applied Catalysis B: Environmental, 2008, 78(3/4): 334-341.

[31] Diagne M, Oturan N, Outran M A. Removal of methyl parathion from water by electrochemically generated Fenton’s reagent[J]. Chemosphere, 2007, 66(5): 841-848.

[32] Oturan M A, Edelahi M C, Oturan N, et al. Kinetics of oxidative degradation/mineralization pathways of the phenylurea herbicides diuron, monuron and fenuron in water during application of the electro-Fenton process[J]. Applied Catalysis B: Environmental, 2010, 97(1/2): 82-89.

[33] Pimentel M, Oturan N, Dezotti M, et al. Phenol degradation by advanced electrochemical oxidation process electro-Fenton using a carbon felt cathode[J]. Applied Catalysis B: Environmental, 2008, 83(1/2): 140-149.

[34] Beltran-Heredia J, Torregrosa J, Dominguez J R, et al. Comparison of the degradation of p-hydroxybenzoic acid in aqueous solutions by several oxidation processes[J]. Chemosphere, 2001, 42(4): 351-359.

[35] Hammami S, Ouejhani A, Bellakhal N, et al. Application of Doehlert matrix to determine the optimal conditions of electrochemical treatment of tannery effluents[J]. Journal of Hazardous Materials, 2009, 163(1): 251-258.

[36] Ouejhani A, Hellal F, Dachraoui M, et al. Application of Doehlert matrix to the study of electrochemical oxidation of Cr(III) to Cr(VI) in order to recover chromium from wastewater tanning baths[J]. Journal of Hazardous Materials, 2008, 157(2/3) 423-431.

[37] Mathieu D, Luu R P T. Software NEMROD, Université d’AiX-Marseille III, France (1980).

[38] Sires I, Garrido J A, Rodr?guez R M, et al. Electrochemical degradation of paracetamol from water by catalytic action of Fe2+, Cu2+, and UVA light on electrogenerated hydrogen peroxide[J]. Journal of the Electrochemical Society, 2006, 153(1): D1-D9.

[39] Sires I, Centellas F, Garrido J A, et al. Mineralization of clo?bric acid by electrochemical advanced oxidation processes using a boron-doped diamond anode and Fe2+ and UVA light as catalysts[J]. Applied Catalysis B: Environmental, 2007, 72(3/4): 373-381.

[40] Boye B, Dieng M M, Brillas E. Degradation of herbicide 4-chlorophenoxyacetic acid by advanced electrochemical oxidation methods[J]. Environmental Science & Technology 2002, 36(13): 3030-3035.

[41] Gandini D, Mahe E, Michaud P A, et al. OXidation of carboxylic acids at boron-doped diamond electrodes for wastewater treatment[J]. Journal of Applied Electrochemistry, 2000, 30(12): 1345-1350.

[42] ?zcan A, Sahin Y, Oturan M A. Removal of propham from water by using electro-Fenton technology: Kinetics and mechanism[J]. Chemosphere, 2008, 73(5): 737-744.
[43] Trabelsi Souissi S, Bellakhal N, Oturan N, et al. Application of the photo-Fenton process to the mineralization of phthalic anhydride in aqueous medium[J]. Desalination & Water Treatment, 2011, 25(1/3): 210-215.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.