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Insight into Advanced Oxidation Processes for Wastewater Treatment
Published in Maulin P. Shah, Sweta Parimita Bera, Günay Yıldız Töre, Advanced Oxidation Processes for Wastewater Treatment, 2022
Surbhi Sinha, Sonal Nigam, Muskan Syed
Anodic oxidation, also known as electrooxidation is a process extensively utilized for the treatment of industrial wastewater. Generally, the process consists of two electrodes, anode and cathode, linked to a power supply. When sufficient power input and electrolytes are given to the system, strong oxidizing agents, particularly hydroxyl radicals, are formed. The OH• radicals then cause the degradation of the contaminants (Anglada et al., 2009). The mechanism of degradation in anodic oxidation is represented as follows: ()S+H2O→S(OH•)+H•+e− Where S represents the adsorption site on the surface of the electrode. Various electrodes such as Pt, boron-doped diamond (BDD), Ti/SnO2 and PbO2 with high oxygen voltage are commonly utilized in the present method (Fernandes et al., 2014; Chaplin et al., 2013). Also, the type of electrode and the conditions for electrolysis play a crucial role in wastewater treatment.
Materials Involved in Electrocoagulation Process for Industrial Effluents
Published in Mu Naushad, Saravanan Rajendran, Abdullah M. Al-Enizi, New Technologies for Electrochemical Applications, 2020
Carlos Navas-Cárdenas, Herman Murillo, Maibelin Rosales, Cesar Ron, Florinella Muñoz
In this context, electrochemical methods such as electrocoagulation (EC), electrooxidation, electroflotation, and photo-assisted electrochemical methods have been emerging as alternatives of wastewater treatment, and are based on the use of electrons as the working agents to promote the pollutant removal (Brillas and Martínez-Huitle 2015; Moussa et al. 2017; Yavuz and Ogütveren 2018). Among the electrochemical methods, EC is one of the most promising water treatment technologies employed to remove refractory pollutants from industrial effluents. The EC process involves electrochemical reactions to lead the in situ formation of coagulating agents by the electrodissolution of a sacrificial anode due to the applied electric field to the electrodes (Aljaberi 2018; Chen 2004; Meas et al. 2010). The advantages of EC over conventional wastewater treatments include high removal efficiency, use of less or no chemicals, compact treatment facilities, relatively low cost, lower amount sludge production, and the possibility of complete automation (An et al. 2017; Jiang et al. 2017; Kobya et al. 2011).
Conventional and advanced treatment technologies for palm oil mill effluents: a systematic literature review
Published in Journal of Dispersion Science and Technology, 2021
G. Yashni, Adel Al-Gheethi, Radin Maya Saphira Radin Mohamed, Siti Nor Hidayah Arifin, Siti Nor Aishah Mohd Salleh
Electro-oxidation is also an effectual method for pollutant degradation by using electrochemically produced oxidants or anodic adsorbed oxidants to concurrently perform direct and indirect oxidation.[55] This procedure utilizes electric potential where ionized metallic species are coated on the cathode surface. This procedure needs less chemicals and generates fewer sludge, but the high initial capital cost and costly electricity source reduce its efficiency.[106] Bashir et al.[55] explored electro-oxidation of POME at optimum operational conditions with 45 mA/cm2 of current density, 45 minutes of contact time, pH 4 and 0.892 g of S2O82- and achieved COD removals of 77.70%, color removal of 97.96% and SS removals of 99.72%.
Synthesis and characterization of ternary metallic oxide electrodes containing (SnO2)93Sb5M2 (M = Ce, ta, Bi, Gd) using an ionic liquid as the precursor solvent
Published in Chemical Engineering Communications, 2020
Marilia Moura de Salles Pupo, Leticia Mirella da Silva, Géssica de Oliveira Santiago Santos, Katlin Ivon Barrios Eguiluz, Giancarlo Richard Salazar-Banda
One of the main restrictions in electrochemical systems is the electrodes used to promote electro-oxidation. In this sense, dimensionally stable anodes (DSAs) have received considerable attention due to their electrocatalytic advantages, such as long service lifetime and high electroactive area. In addition, they present low production cost and easy synthesis. Similarly, mixed metal oxide (MMO) electrodes are basically composed of a metallic substrate, normally Ti due to its stability and uniformity, and a metal oxide as a coating layer, such as RuO2, IrO3, TiO2, SnO2, PbO2, and Ta2O5 (Li et al. 2016; Pupo et al. 2013; Shao et al. 2014; Xu & Song 2015).
Pre-treatment of soft drink wastewater with a calcium-modified zeolite to improve electrooxidation of organic matter
Published in Journal of Environmental Science and Health, Part A, 2019
Rosa Elia Victoria-Salinas, Verónica Martínez-Miranda, Ivonne Linares-Hernández, Guadalupe Vázquez-Mejía, Monserrat Castañeda-Juárez, Perla Tatiana Almazán-Sánchez
However, in the electrooxidation processes, the optimum pH of operation is in the acidic range (2.8–4). Thus, the high stability provided by the alkaline species hinders chemical and biological oxidation processes. Generally, during electrochemical oxidation, the different ions in water, such as carbonates, sulphates, and phosphates, may act as scavengers of hydroxyl radicals.[24,25]