Comparative study of the removal of direct red 23 by anodic oxidation, electro-Fenton, photo-anodic oxidation and photoelectro-Fenton in chloride and sulfate media

Photo‐Alternating Current‐Electro‐Fenton Process for Pollutant Removal and Energy Usage from Industrial Wastewater: Response Surface Approach Optimization of Operational Parameters

“…This was shown by the fact that the UV+AC+EF process produced the best outcomes [41] . In addition, the data indicate that light and electricity work together to provide a synergistic effect [24,42,43] …”

“…PEF process with the assistance of UV light is advantageous in accelerating the degradation process through the photo‐reduction of Fe(III)‐hydroxyl species (Fe(OH) 2+ ) and photodecomposition of Fe(III)‐carboxylate intermediates (Fe(RCOO) 2+ ) in the working solution (eqs. (5–8)) [24,25] . A constraint of the PEF method is the need for an external power source to run the process. $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr Fe{\left(OH\right)}^{2+}+hv\to H{O}^{\bullet }+{Fe}^{2+}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {H}_{2}{O}_{2}+hv\ \to 2H{O}^{\bullet }\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr Fe{\left(OOCR\right)}^{2+}+hv\to {Fe}^{2+}+{CO}_{2\left(g\right)}+\ {R}^{\bullet }\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr Organic\ polltant+hv\ \to Oxidation\ products{\rm \ }\hfill\cr}}$$$ …”

“…They discovered that the BRDR system considerably enhanced ciprofloxacin elimination efficiency to 99.9 % when compared to individual efficiencies of photoelectrocatalysis (71 %) and photo‐electro‐Fenton (78.8 %). Titchou et al [24] . studied the degradation and mineralization of an 80 mg L −1 dye DR23 solution by several EAOPs such as AO‐H 2 O 2 , EF, PAO, and PEF.…”

Boosting Hydroxyl Radical Yield via Synergistic Activation of Electrogenerated HOCl/H2O2 in Electro-Fenton-like Degradation of Contaminants under Chloride Conditions

“…Nevertheless, it is interesting to note that TOC removal under chloride conditions is almost the same as in sulfate only media (above 60%) in just 2 h (Figure d), which is contrary to previous studies where mineralization was seriously inhibited under chloride conditions, which the authors associated with the formation of iron–chloro complexes that could inhibit • OH generation from HOCl activation by metal catalyst, ,, whereas the activation of HOCl into a large amount of high oxidation power • OH by the metal-free BNDC/GF6 cathode in this study resulted in high mineralization efficiency. Slightly lower TOC removal at 70 mM NaCl could be due to highly resistant organo-chlorines produced under high chloride concentrations. , These results show that highly efficient performance by the BNDC/GF6 cathode can be attributed to the synergetic activation of H 2 O 2 and HOCl to • OH under high chloride conditions.…”

Recent advances in electro-Fenton process and its emerging applications

“…Ability of BDD to generate persulfate and sulfate radicals from electrolyte containing sulfate ions (Divyapriya & Nidheesh, 2021) in addition to • OH generation via Fenton reaction and anodic oxidation of water, enhanced the efficiency of EF process significantly(Midassi et al, 2020). The enhancement in treatment efficiency of EF process, further improved by coupling with other process such as anodic photo-electrochemical oxidation(Orimolade et al, 2020;Titchou et al, 2022), photo-EF (Ye…”