Degradation of multicomponent pharmaceutical mixtures by electrochemical oxidation: Insights about the process evolution at varying applied currents and concentrations of organics and supporting electrolyte
[EN] Electrochemical oxidation is a treatment process that can achieve high degrees of removal of organic emerging pollutants from wastewater. The present study evaluates the removal and mineralization degrees achieved when treating by electrochemical oxidation multicomponent mixtures containing thr...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/229141 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/229141 |
| Access Level: | acceso abierto |
| Palabra clave: | Advanced oxidation Boron-doped diamond Electrochemical oxidation Hydroxyl radical Mineralization Pharmaceuticals Persulfate ion |
| Sumario: | [EN] Electrochemical oxidation is a treatment process that can achieve high degrees of removal of organic emerging pollutants from wastewater. The present study evaluates the removal and mineralization degrees achieved when treating by electrochemical oxidation multicomponent mixtures containing three model pharmaceuticals: atenolol, ibuprofen and norfloxacin. The progress of the removal process at different applied currents was followed through the evolution of the degree of mineralization and the concentration of ionic by-products. The three compounds can be effectively removed, although atenolol was found to be the most recalcitrant one. An increase in the degree of mineralization with current was noted for currents above 200 mA, reaching a maximum value of 98.8 % for an operation current of 800 mA. In general, total organic carbon declines linearly during the first stages of the process, while an exponential trend appears at the latter stages when complete mineralization is approached. Peak concentrations of some by-products, such as formate, ammonia and nitrite ions, were detected at intermediate operating times. Such compounds are further oxidized, thus being depleted from the solution towards the end of the process. On the contrary, a final plateau concentration is reached for fluoride and nitrate ions. Such events occur faster at higher operation currents, thus denoting an accelerated process of mineralization. However, higher currents also induce a decrease in the mineralization current efficiency and an increase in the specific energy consumption. Notably, for a given current, the process evolves at a similar pace regardless of the concentration of organics and supporting electrolyte. In terms of net mineralization, this implies a more efficient utilization of the generated hydroxyl radicals in the removal of organics for higher solution concentrations. Experiments conducted at constant current and organics concentration, but varying the concentration of sodium sulfate, confirmed that hydroxyl radicals are the main species responsible for the removal of pharmaceuticals, whereas the oxidation of the supporting electrolyte only plays a secondary role. |
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