Electrodegradation of naphthalenic amines: Influence of the relative position of the substituent groups, anode material and electrolyte on the degradation products and kinetics
Autor: | Ana Lopes, J.N. Silva, Ana Sofia Rodrigues, Lurdes Ciríaco, M.J. Nunes, Maria José Pacheco |
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Rok vydání: | 2018 |
Předmět: |
Environmental Engineering
Nitrogen Health Toxicology and Mutagenesis Sodium Oxalic acid chemistry.chemical_element 02 engineering and technology Electrolyte Naphthalenes 010501 environmental sciences 01 natural sciences Chloride Electrolysis law.invention Acetic acid chemistry.chemical_compound law Sodium sulfate medicine Environmental Chemistry Amines Sulfate Electrodes 0105 earth and related environmental sciences Titanium Sulfates Public Health Environmental and Occupational Health General Medicine General Chemistry 021001 nanoscience & nanotechnology Pollution Kinetics chemistry Sulfonic Acids 0210 nano-technology Oxidation-Reduction Water Pollutants Chemical medicine.drug Nuclear chemistry |
Zdroj: | Chemosphere. 205:433-442 |
ISSN: | 0045-6535 |
DOI: | 10.1016/j.chemosphere.2018.04.104 |
Popis: | The electrodegradation of the 4-aminonaphthalene-1-sulfonic acid (4AN1S), 5-aminonaphthalene-2-sulfonic acid (5AN2S) and 8-aminonaphthalene-2-sulfonic acid (8AN2S) was studied, using two electrode materials as anode, BDD and Ti/Pt/PbO2, and two different electrolytes, sodium sulfate and sodium chloride. The highest COD removal rates were obtained at BDD: for 5AN2S and 8AN2S results were similar in both electrolytes; for 4AN1S, results were better in sodium chloride. The lowest COD removal rates were obtained at the system Ti/Pt/PbO2-sodium sulfate, for all the studied amines. The dissolved organic carbon (DOC) removal was much higher at BDD for all the amines, in sulfate for 5AN2S and 8AN2S and in chloride for 4AN1S. Nitrogen removal was always almost irrelevant in sulfate medium but higher than 60%, after 6-h assays, in chloride. The highest combustion efficiencies were attained at the system BDD-sodium sulfate and were: 4AN1S-75%; 5AN2S-84%; 8AN2S-74%. HPLC results show that total degradation of the studied aminonaphthalene sulfonates is attained at both anode materials, utilizing any of the electrolytes, with a first order kinetics. However, kinetic constants obtained with the variation of the amines concentration in time are 10-40 times higher in chloride, being slightly higher at Ti/Pt/PbO2 than at BDD. Regarding the presence of carboxylic acids during the degradation assays, it was observed that the electrolysis of the amines 5AN2S and 8AN2S always lead to higher amounts of oxalic acid and lower quantities of acetic acid than the electrolysis of the amine 4AN1S. |
Databáze: | OpenAIRE |
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