Qiang ZHAO, Baichen LIU, Liman ZHANG, Hailong SUN, Yingwu YAO, Feng WEI

Process optimization and mechanism study of acid red G degradation by electro-FentonFeox process as an in situ generation of $H_2O_2$

Dye-contaminated wastewaters are industrial wastewaters that are difficult to treat using traditional biochemical and physicochemical methods. In the present work, the acid red G was removed as a model pollutant by the electro-Fenton process for the first time. The anode and cathode used by the electro-Fenton process were iron plate and graphite felt, respectively. It was concluded that under the optimal conditions of current density = 20 mA $cm^{–2}$, pH = 3 and initial $Na_2SO_4$ concentration = 0.2 M, the removal rate of acid red G (ARG) with an initial concentration of 300 mg L–1 could reach 94.05% after 80 min of electrolysis. This reveals that the electroFenton-Feox process used in this work has an excellent removal efficiency on acid red G. The required reagents $(Fe^{2+} and H_2O_2 )$ were generated by the electrode reaction, while the optimal generation conditions and mechanism of •OH, $H_2O_2$, and $Fe^{2+}$ were investigated. By testing •OH, $H_2O_2$, and $(Fe^{2+} agents at different pH and current densities, it was revealed that the electro-Fenton reaction was most efficient when the current density was 20 mA cm–2, and the pH was 3. Moreover, the removal rate of ARG is consistent with first-order reaction kinetics.

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1. Salazar R, Ureta-Zañartu M. Mineralization of triadimefon fungicide in water by electro-Fenton and photo electro-Fenton. Water, Air, & Soil Pollution 2012; 223 (7): 4199-4207. doi: 10.1007/s11270-012-1184-7
2. Bello MM, Raman AAA, Asghar A. A review on approaches for addressing the limitations of Fenton oxidation for recalcitrant wastewater treatment. Process Safety and Environmental Protection 2019; 126: 119-140. doi: 10.1016/j.psep.2019.03.028
3. Dang X, Chen H, Shan Z, Zhen W, Yang M. The oxidation of potato starch by electro-Fenton system in the presence of Fe (II) ions. International Journal of Biological Macromolecules 2019; 121: 113-119. doi: 10.1016/j.ijbiomac.2018.10.012
4. Cao Z, Zheng X, Cao H, Zhao H, Sun Z et al. Efficient reuse of anode scrap from lithium-ion batteries as cathode for pollutant degradation in electro-Fenton process: Role of different recovery processes. Chemical Engineering Journal 2018; 337: 256-264. doi: 10.1016/j. cej.2017.12.104
5. Arellano M, Oturan N, Pazos M, Sanromán MÁ, Oturan MA. Coupling electro-Fenton process to a biological treatment, a new methodology for the removal of ionic liquids. Separation and Purification Technology 2020; 233: 115990. doi: 10.1016/j.seppur.2019.115990
6. Casado J. Towards industrial implementation of Electro-Fenton and derived technologies for wastewater treatment: A review. Journal of Environmental Chemical Engineering 2019; 7 (1): 102823. doi: 10.1016/j.jece.2018.102823
7. Chen S, Tang L, Feng H, Zhou Y, Zeng G et al. Carbon felt cathodes for electro-Fenton process to remove tetracycline via synergistic adsorption and degradation. Science of the Total Environment 2019; 670: 921-931. doi: 10.1016/j.scitotenv.2019.03.086
8. Chen Y, Chen H, Li J, Xiao L. Rapid and efficient activated sludge treatment by electro-Fenton oxidation. Water Research 2019; 152: 181- 190. doi: 10.1016/j.watres.2018.12.035
9. Choe YJ, Kim J, Ji YB, Kim SH. An electro-Fenton system with magnetite coated stainless steel mesh as cathode. Catalysis Today 2019. doi: 10.1016/j.cattod.2019.06.062
10. Colades JI, Huang C-P, Retumban JD, Garcia-Segura S, de Luna MDG. Electrochemically-driven dosing of iron (II) for autonomous electro-Fenton processes with in situ generation of $H_2O_2$. Journal of Electroanalytical Chemistry 2020; 856: 113639. doi: 10.1016/j. jelechem.2019.113639
11. Cao P, Quan X, Zhao K, Chen S, Yu H et al. Selective electrochemical $H_2O_2$ generation and activation on a bifunctional catalyst for heterogeneous electro-Fenton catalysis. Journal of hazardous materials2020; 382: 121102. doi: 10.1016/j.jhazmat.2019.121102
12. Díez A, Pazos M, Sanromán M. Bifunctional floating catalyst for enhancing the synergistic effect of LED-photolysis and electro-Fenton process. Separation and Purification Technology 2020; 230: 115880. doi: 10.1016/j.seppur.2019.115880
13. Gao Y, Zhu W, Wang C, Zhao X, Shu M et al. Enhancement of oxygen reduction on a newly fabricated cathode and its application in the electro-Fenton process. Electrochimica Acta 2020; 330: 135206. doi: 10.1016/j.electacta.2019.135206
14. Kubo D, Kawase Y. Hydroxyl radical generation in electro-Fenton process with in situ electro-chemical production of Fenton reagents by gas-diffusion-electrode cathode and sacrificial iron anode. Journal of Cleaner Production 2018; 203: 685-695. doi: 10.1016/j. jclepro.2018.08.231
15. Zhang G, Gong J, Zou X, He F, Zhang Q et al. Photocatalytic degradation of azo dye acid red G by $KNb_3O_8$ and the role of potassium in the photocatalysis. Chemical Engineering Journal2006; 123 (1-2): 59-64. doi: 10.1016/j.cej.2006.06.021
16. Shoorangiz M, Nikoo MR, Salari M, Rakhshandehroo GR, Sadegh M. Optimized electro-Fenton process with sacrificial stainless steel anode for degradation/mineralization of ciprofloxacin. Process Safety and Environmental Protection 2019; 132: 340-350. doi: 10.1016/j. psep.2019.10.011
17. Contreras MBC, Fourcade F, Assadi A, Amrane A, Fernandez-Morales FJ. Electro Fenton removal of clopyralid in soil washing effluents. Chemosphere 2019; 237: 124447. doi: 10.1016/j.chemosphere.2019.124447
18. Sellers R M. Spectrophotometric determination of hydrogen peroxide using potassium titanium (IV) oxalate. Analyst 1980, 105. doi: 10.1039/an9800500950
19. Jean-M F, Xochitl D-B, Mika S. Towards reliable quantification of hydroxyl radicals in the Fenton reaction using chemical probes. RSC Advances 2018; 8 (10): 5321-5330. doi: 10.1039/c7ra13209c
20. Kourdali S, Badis A, Boucherit A, Boudjema K, Saiba A. Electrochemical disinfection of bacterial contamination: effectiveness and modeling study of E. coli inactivation by electro-Fenton, electro-peroxi-coagulation and electrocoagulation. Journal of Environmental Management 2018; 226: 106-119. doi: 10.1016/j.jenvman.2018.08.038
21. Zou X, Wan Z, Wan C, Zhang G, Pan X et al. Novel $Ag/AgCl/K_6 Nb_{10.8}O_{30}$ photocatalyst and its enhanced visible light photocatalytic activities for the degradation of microcystin-LR and acid red G. Journal of Molecular Catalysis A: Chemical 2016; 411: 364-371. doi: 10.1016/j.molcata.2015.11.009
22. Wang T, Zhao P, Lu N, Chen H, Zhang C et al. Facile fabrication of $Fe_3O_4/MIL-101(Cr)$ for effective removal of acid red 1 and orange G from aqueous solution. Chemical Engineering Journal 2016; 295: 403-413. doi: 10.1016/j.cej.2016.03.016
23. Feng J, Li J, Lv W, Xu H, Yang H et al. Synthesis of polypyrrole nano-fibers with hierarchical structure. Synthetic Metals 2014; 191: 66-73. doi: 10.1016/j.synthmet.2014.02.013
24. Tong D, Liu M, Li L, Lin C, Yu W et al. Transformation of alunite residuals into layered double hydroxides and oxides for adsorption of acid red G dye. Applied Clay Science 2012; 70: 1-7. doi: 10.1016/j.clay.2012.08.001
25. Lei J, Xu Z, Xu H, Qiao D, Liao Z et al. Pulsed electrochemical oxidation of acid Red G and crystal violet by PbO2 anode. Journal of Environmental Chemical Engineering 2020; 8: 103773. doi: 10.1016/j.jece.2020.103773
26. Garcia-Segura S, Keller J, Brillas E, Radjenovic J. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment. Journal of Hazardous Materials 2015; 283: 551-557. doi: 10.1016/j.jhazmat.2014.10.003
27. Zhao K, Quan X, Chen S, Yu H, Zhao J. Preparation of fluorinated activated carbon for electro-Fenton treatment of organic pollutants in coking wastewater: The influences of oxygen-containing groups. Separation and Purification Technology 2019; 224: 534-542. doi: 10.1016/j.seppur.2019.05.058
28. Zou R, Angelidaki I, Jin B, Zhang Y. Feasibility and applicability of the scaling-up of bio-electro-Fenton system for textile wastewater treatment. Environment International 2020; 134: 105352. doi: 10.1016/j.envint.2019.105352
29. Changotra R, Rajput H, Dhir A. Treatment of real pharmaceutical wastewater using combined approach of Fenton applications and aerobic biological treatment. Journal of Photochemistry and Photobiology A: Chemistry2019; 376: 175-184. doi: 10.1016/j.jphotochem.2019.02.029
30. Acisli O, Khataee A, Soltani RDC, Karaca S. Ultrasound-assisted Fenton process using siderite nanoparticles prepared via planetary ball milling for removal of reactive yellow 81 in aqueous phase. Ultrasonics Sonochemistry 2017; 35: 210-218. doi: 10.1016/j. ultsonch.2016.09.020
31. Zhou M, Yu Q, Lei L, Barton G. Electro-Fenton method for the removal of methyl red in an efficient electrochemical system. Separation and Purification Technology 2007; 57 (2): 380-387. doi: 10.1016/j.seppur.2007.04.021
32. Wang Y, Chu W. Photo-assisted degradation of 2, 4, 5-trichlorophenol by Electro-Fe (II)/Oxone® process using a sacrificial iron anode: Performance optimization and reaction mechanism. Chemical Engineering Journal 2013; 215: 643-650. doi: 10.1016/j.cej.2012.11.042
33. Pignatello J J , Liu D , Huston P . Evidence for an additional oxidant in the photoassisted fenton reaction. Environmental Science & Technology 1999; 33(11): 1832-1839. doi: 10.1021/es980969b
34. Shemer H, Kunukcu YK, Linden KG. Degradation of the pharmaceutical metronidazole via UV, Fenton and photo-Fenton processes. Chemosphere2006; 63 (2): 269-276. doi: 10.1016/j.chemosphere.2005.07.029
35. Panizza M, Cerisola G. Electro-Fenton degradation of synthetic dyes. Water Research 2009; 43 (2): 339-344. doi: 10.1016/j.watres.2008.10.028
36. Das R, Bhaumik M, Giri S, Maity A. Sonocatalytic rapid degradation of congo red dye from aqueous solution using magnetic $Fe_0/$polyaniline nanofibers. Ultrasonics Sonochemistry 2017; 37, 600-613. doi: 10.1016/j.ultsonch.2017.02.022
37. Sennaoui A, Alahiane S, Sakr F, Tamimi M, Hamdani M et al. Comparative degradation of benzoic acid and its hydroxylated derivatives by electro-Fenton technology using BDD/carbon-felt cells. Journal of Environmental Chemical Engineering 2019; 7 (2): 103033. doi: 10.1016/j.jece.2019.103033
38. Sopaj F, Oturan N, Pinson J, Podvorica FI, Oturan MA. Effect of cathode material on electro-Fenton process efficiency for electrocatalytic mineralization of the antibiotic sulfamethazine. Chemical Engineering Journal 2020; 384: 123249. doi: 10.1016/j.cej.2019.123249
39. Yang H, Zhou M, Yang W, Ren G, Ma L. Rolling-made gas diffusion electrode with carbon nanotube for electro-Fenton degradation of acetylsalicylic acid. Chemosphere 2018; 206: 439-446. doi: 10.1016/j.chemosphere.2018.05.027
40. Stupar SL, Grgur BN, Radišić MM, Onjia AE, Mijin DŽ. Oxidative degradation of acid blue 111 by electro-assisted fenton process. Journal of Water Process Engineering 2020; 36, 101394. doi: 10.1016/j.jwpe.2020.101394
41. Khataee A, Gholami P, Sheydaei MJ. Heterogeneous Fenton process by natural pyrite for removal of a textile dye from water: Effect of parameters and intermediate identification. Journal of the Taiwan Institute of Chemical Engineers 2016; 58, 366-373. doi: 10.1016/j. jtice.2015.06.015
42. Solano A M S, Garcia-Segura S, Martínez-Huitle C A, Brillas E. Degradation of acidic aqueous solutions of the diazo dye Congo Red by photo-assisted electrochemical processes based on Fenton’s reaction chemistry. Applied Catalysis B Environmental 2015; 168-169: 559- 571. doi:10.1016/j.apcatb.2015.01.019
43. Murrieta MF, Sires I, Brillas E, Nava JL. (2020). Mineralization of Acid Red 1 azo dye by solar photoelectro-Fenton-like process using electrogenerated HClO and photoregenerated Fe(II). Chemosphere 2020; 246, 125697. doi: 10.1016/j.chemosphere.2019.125697
44. Emami F, Tehrani-Bagha A. R, Gharanjig K, Menger F M. Kinetic study of the factors controlling fenton-promoted destruction of a nonbiodegradable dye. Desalination 2010; 257(1-3), 124-128. doi: 10.1016/j.desal.2010.02.035