Hydrogen production from electrochemical treatment of textile dyeing wastewaters
Textile dyeing processes produce non-biodegradable, intensively coloured effluents, which contain unreacted dye molecules and are not efficiently treated by conventional biological treatments. Electrochemical processes are an alternative with an added value that is normally ignored because of a lack...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/411616 |
| Acceso en línea: | https://hdl.handle.net/2117/411616 https://dx.doi.org/10.1016/j.jwpe.2024.105628 |
| Access Level: | acceso abierto |
| Palabra clave: | Hydrogen Sewage--Purification Electrolysis Hydrogen production Wastewater treatment Textile industry Alkaline electrolysis Hidrogen Aigües residuals--Depuració Aigua--Electròlisi Àrees temàtiques de la UPC::Enginyeria química::Química física::Electroquímica Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament de l'aigua |
| Sumario: | Textile dyeing processes produce non-biodegradable, intensively coloured effluents, which contain unreacted dye molecules and are not efficiently treated by conventional biological treatments. Electrochemical processes are an alternative with an added value that is normally ignored because of a lack of evidence and supporting studies: the simultaneous production of hydrogen and its potential. This study assesses the capability of electrochemical processes to eliminate the colour from textile dyeing wastewaters while hydrogen is produced as a by-product. Four textile dyeing effluents containing the four most commonly used reactive azo dyes were treated in a Hofmann Voltameter. The results indicate that lower current densities are more energy-efficient working conditions for both studied variables (discolouration and hydrogen production), although they lead to a slower process. Discolouration of the effluents is >90 % with a consumption of 5 kWh/m3 in the most efficient conditions. The presence of the dye has no effect on hydrogen generation flows or performance in function of the applied current. Hydrogen production efficiencies of around 80–95 % are achieved, compared to the theoretical maximum. The effluent's electrical conductivity is the only variable that affects the results, with greater conductivity implying better energy performance. The hydrogen produced had no impurities due to the effluent composition and stored up to 20 % of the energy consumed during the treatment under the most efficient working conditions (20–25 mA/cm2). Therefore, it is available for energy recovery and represents an incentive to use electrochemical treatment of wastewaters with anode-cathode separation and hydrogen capture on the cathode. |
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