Electro-oxidation

Electro-oxidation (EO or EOx), also known as anodic oxidation or electrochemical oxidation (EC), is a technique used for wastewater treatment, mainly for industrial effluents, and is a type of advanced oxidation process (AOP).[1] The most general layout comprises two electrodes, operating as anode and cathode, connected to a power source. When an energy input and sufficient supporting electrolyte are provided to the system, strong oxidizing species are formed, which interact with the contaminants and degrade them. The refractory compounds are thus converted into reaction intermediates and, ultimately, into water and CO2 by complete mineralization.[2]

Electro-oxidation has recently grown in popularity thanks to its ease of set-up and effectiveness in treating harmful and recalcitrant organic pollutants, which are typically difficult to degrade with conventional wastewater remediation processes.[3] Also, it does not require any external addition of chemicals (contrary to other processes), as the required reactive species are generated at the anode surface.[2]

Electro-oxidation has been applied to treat a wide variety of harmful and non-biodegradable contaminants, including aromatics, pesticides, drugs and dyes.[4][5][6][7][8] Due to its relatively high operating costs, it is often combined with other technologies, such as biological remediation.[9] Electro-oxidation can additionally be paired with other electrochemical technologies such as electrocoagulation, consecutively or simultaneously,[10] to further reduce operational costs while achieving high degradation standards.

  1. ^ Sirés, Ignasi; Brillas, Enric; Oturan, Mehmet A.; Rodrigo, Manuel A.; Panizza, Marco (2014). "Electrochemical advanced oxidation processes: today and tomorrow. A review". Environmental Science and Pollution Research. 21 (14): 8336–8367. doi:10.1007/s11356-014-2783-1. hdl:10578/10619. ISSN 0944-1344. PMID 24687788. S2CID 29448445.
  2. ^ a b Anglada, Ángela; Urtiaga, Ane; Ortiz, Inmaculada (2009). "Contributions of electrochemical oxidation to waste-water treatment: fundamentals and review of applications". Journal of Chemical Technology & Biotechnology. 84 (12): 1747–1755. doi:10.1002/jctb.2214.
  3. ^ Särkkä, Heikki; Bhatnagar, Amit; Sillanpää, Mika (2015). "Recent developments of electro-oxidation in water treatment — A review". Journal of Electroanalytical Chemistry. 754: 46–56. doi:10.1016/j.jelechem.2015.06.016.
  4. ^ Robles-Molina, José; Martín de Vidales, María J.; García-Reyes, Juan F.; Cañizares, Pablo; Sáez, Cristina; Rodrigo, Manuel A.; Molina-Díaz, Antonio (2012). "Conductive-diamond electrochemical oxidation of chlorpyrifos in wastewater and identification of its main degradation products by LC–TOFMS". Chemosphere. 89 (10): 1169–1176. Bibcode:2012Chmsp..89.1169R. doi:10.1016/j.chemosphere.2012.08.004. PMID 22947255.
  5. ^ Brillas, Enric; Sirés, Ignasi; Arias, Conchita; Cabot, Pere Lluís; Centellas, Francesc; Rodríguez, Rosa María; Garrido, José Antonio (2005). "Mineralization of paracetamol in aqueous medium by anodic oxidation with a boron-doped diamond electrode". Chemosphere. 58 (4): 399–406. Bibcode:2005Chmsp..58..399B. doi:10.1016/j.chemosphere.2004.09.028. PMID 15620731.
  6. ^ Chu, Yan-yang; Wang, Wei-jing; Wang, Meng (2010). "Anodic oxidation process for the degradation of 2, 4-dichlorophenol in aqueous solution and the enhancement of biodegradability". Journal of Hazardous Materials. 180 (1–3): 247–252. doi:10.1016/j.jhazmat.2010.04.021. PMID 20444547.
  7. ^ Bogdanowicz, R.; Fabiańska, A.; Golunski, L.; Sobaszek, M.; Gnyba, M.; Ryl, J.; Darowicki, K.; Ossowski, T.; Janssens, S.D. (2013). "Influence of the boron doping level on the electrochemical oxidation of the azo dyes at Si/BDD thin film electrodes". Diamond and Related Materials. 39: 82–88. Bibcode:2013DRM....39...82B. doi:10.1016/j.diamond.2013.08.004.
  8. ^ Ramírez, Cecilia; Saldaña, Adriana; Hernández, Berenice; Acero, Roberto; Guerra, Ricardo; Garcia-Segura, Sergi; Brillas, Enric; Peralta-Hernández, Juan M. (2013). "Electrochemical oxidation of methyl orange azo dye at pilot flow plant using BDD technology". Journal of Industrial and Engineering Chemistry. 19 (2): 571–579. doi:10.1016/j.jiec.2012.09.010.
  9. ^ Ganzenko, Oleksandra; Huguenot, David; van Hullebusch, Eric D.; Esposito, Giovanni; Oturan, Mehmet A. (2014). "Electrochemical advanced oxidation and biological processes for wastewater treatment: a review of the combined approaches". Environmental Science and Pollution Research. 21 (14): 8493–8524. doi:10.1007/s11356-014-2770-6. ISSN 0944-1344. PMID 24965093. S2CID 5049220.
  10. ^ Sato, Yugo; Zeng, Qian; Meng, Liao; Chen, Guanghao (March 2021). "Importance of Combined Electrochemical Process Sequence and Electrode Arrangements: A Lab-scale Trial of Real Reverse Osmosis Landfill Leachate Concentrate". Water Research. 192: 116849. doi:10.1016/j.watres.2021.116849. PMID 33517046. S2CID 231759895.