INFLUENCE OF CHLORIDE-MEDIATED OXIDATION ON THE ELECTROCHEMICAL DEGRADATION OF THE DIRECT BLACK 22 DYE USING BORON-DOPED DIAMOND AND β-PbO₂ANODES

Electrochemical degradation of the herbicide picloram using a filter-press flow reactor with a boron-doped diamond or β-PbO 2 anode

“…These highly oxidizing species are physically adsorbed on the anode surface [21,42,43]; thus, the oxidation of the organic species is highly dependent on its mass transfer to the anode surface. The BDD and β-PbO2 anodes have been extensively investigated in the electrooxidation of solutions/effluents containing organics due to their excellent chemical stability and high overpotential for the oxygen evolution reaction, which favors • OH electrogeneration [23][24][25]29,31]. Despite the fact that • OH is a potent oxidant, other types of oxidants may be electrolytically generated if certain chemical species are present in solution, such as Cl -or SO41 -ions, when their oxidation leads to the formation of active chlorine (Cl2, HOCl, or OCl -, whose individual concentrations are dependent on the concentration of Cl -and the solution pH, temperature, and ionic strength [44]) or persulfate ions (S2O8 2-) [26,45]; furthermore, hydrogen peroxide (H2O2) may be formed by the combination of hydroxyl radicals [43].…”

“…Electrochemical methods were used to degrade different types of organic compounds in aqueous solutions/effluents [21], including dyes [22][23][24][25][26][27][28][29][30], plasticizers [31,32], pharmaceuticals [33][34][35][36], as well as pesticides [4,[37][38][39][40][41]. These methods are based on the direct and/or indirect oxidation of the organic molecules (and their 4 degradation intermediates), which may lead to total mineralization [21].…”

Optimization of textile azo dye degradation by electrochemical oxidation using Box-Behnken Design

“…Considering that the mediated oxidation of COD by electrogenerated active chlorine is the main process, this behavior could be related to the less production of hypochlorite, which under higher current densities, convert to a chloro oxidants of higher oxidation states (Eq. (9)) 34 . In addition, the concomitant rise in the rate of parasitic anodic oxygen evolution reaction could also contribute and negatively affect the degradation efficiency (Eq.…”

Fenton and solar photo‐Fenton processes in the depuration of wastewater resulting from production of grape juice. A factorial design

“…Electrochemical oxidation is an alternative for the treatment of wastewater, because the production of hydroxyl radicals ( • OH) on the anode allows the mineralization of organic compounds . One disadvantage of this process to take into consideration is the high operational cost caused by the consumption of electrical energy …”

“…12,13 One disadvantage of this process to take into consideration is the high operational cost caused by the consumption of electrical energy. 14 As a way to enhance the performance of wastewater treatment, coagulation/flocculation can be used, which requires low operating and capital costs and is easily applied. 15 The addition of coagulant generates large particles that are agglomerated in the flocculation stage, thus allowing the removal of flocs by decantation or filtration.…”