In this study, mineralization and color removal performance of electro-Fenton method were examined in water containing naphthol blue black (NBB), a diazo dye. NBB was totally converted to intermediate species in a 15-min electrolysis at 60 mA, but complete de-colorization took 180 min. A very high oxidation rate constant ((3.35 ± 0.21) x 10 Ms) was obtained for NBB, showing its high reactivity towards hydroxyl radicals. A very high total organic carbon (TOC) removal value (45.23 mg L) was obtained in the first 60 min of the electro-Fenton treatment of an aqueous solution of NBB (0.25 mM) at 300 mA, indicating the mineralization efficiency of the electro-Fenton method. Mineralization current efficiency values obtained at 300 mA gradually decreased from 24.18% to 4.47% with the electrolysis time, indicating the presence of highly parasitic reactions. Gas chromatography-mass spectrometry analyses revealed that the cleavage of azo bonds of NBB led to formation of different aromatic and aliphatic oxidation intermediates. Ion chromatography analysis showed that ammonium, nitrate and sulfate were the mineralization end-products. The concentration of sulfate ion reached to its quantitative value at the 4th h of electrolysis. On the other hand, the total concentration of ammonium and nitrate ions reached to only 61% of the stoichiometric amount of initial nitrogen after a 7 h electrolysis. Finally, it can be said that the electro-Fenton method is a suitable and efficient method for the removal of NBB and its intermediates from water.
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http://dx.doi.org/10.1016/j.chemosphere.2018.03.125 | DOI Listing |
Chemosphere
February 2025
São Carlos Institute of Chemistry, University of São Paulo, Avenida Trabalhador São Carlense, 400, São Carlos, 13566-590, Brazil. Electronic address:
The present work investigated the application of UVC combined with electrogenerated HO (UVC/e-HO) for BTA degradation using a Printex L6 carbon-based (PL6C) gas diffusion electrode (GDE). The studies were carried out by analyzing the influence of the current density, pH and initial BTA concentration in the contaminant degradation process. Under optimal conditions using 0.
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December 2024
College of Resources and Environment, Chengdu University of Information Technology, Chengdu 610225, Sichuan, China. Electronic address:
In this study, a petal-like ternary metal-layered double hydroxide (FeCoLa-LDH) was synthesized through a facile one-step hydrothermal method and in situ grown on carbon felt (CF). The FeCoLa-LDH/CF composite electrode was applied in a heterogeneous electro-Fenton (HEF) system for the degradation of moxifloxacin hydrochloride (MOX). Characterization revealed that La-doped FeCo-LDH/CF exhibited petal-like layered structure rather than particle's structure, with higher surface defect degree and an increased electroactive surface area (ESA) compared to FeCo-LDH/CF.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Institut Européen des Membranes-IEM (UMR 5635), Univ Montpellier, CNRS, ENSCM 34095 Montpellier France
Per-and polyfluoroalkyl substances (PFAS), known as "forever chemicals", are posing a considerable threat to human health and the environment, that conventional treatment methods are unable to treat. In recent years, electrochemical advanced oxidation emerged as a promising technology for the degradation of recalcitrant pollutants such as PFAS. This work reports the degradation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), using a Magnéli phase-based anode type TiO by electro-oxidation and electro-oxidation combined with electro-Fenton.
View Article and Find Full Text PDFTalanta
March 2025
Department of Analytical and Food Chemistry, University of Vigo, Campus As Lagoas-Marcosende, Vigo, 36310, Spain. Electronic address:
Sulfamethoxazole is an antibiotic that is among the drugs most frequently found in waters around the world because of its habitual consumption and its high chemical stability that prevents it from being eliminated from the environment. In this study, an electroanalytical methodology based on differential pulse voltammetry is developed for the analysis of sulfamethoxazole at trace levels in water. After the optimization of the instrumental parameters a linear range from 6.
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November 2024
Institute of Environmental Engineering, National Sun Yat-sen University, Taiwan.
High-strength wastewater containing elevated levels of chloride salt and N, N-dimethylformamide (DMF) solvent was collected from manufacturing of sunscreen cream (for UVA/UVB protection) at a cosmetic factory. In evaporation process, precipitates, formed due to the high chloride content (around 160 g/L), clog the pipeline, seriously reducing the treatment efficiency. This study aimed to develop a two-stage process integrating chemical precipitation and electrochemical oxidation to specifically remove the concentrated chloride salt and organic compounds (COD >100 g/L).
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