Pulsed light for a cleaner dyeing industry: Azo dye degradation by an advanced oxidation process driven by pulsed light
Water pollution by wastewater containing dyes is an environmental issue that can be mitigated by the use of advanced oxidation processes (AOP). Pulsed light (PL) is an emerging food processing technology that uses eco-friendly lamps and can potentially be adapted as light source of an UV-based AOP....
| Autores: | , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2019 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/202555 |
| Acesso em linha: | http://hdl.handle.net/10261/202555 |
| Access Level: | acceso abierto |
| Palavra-chave: | Azo dyes Advanced oxidation processes Ferrioxalate Pulsed light Wastewater remediation |
| Resumo: | Water pollution by wastewater containing dyes is an environmental issue that can be mitigated by the use of advanced oxidation processes (AOP). Pulsed light (PL) is an emerging food processing technology that uses eco-friendly lamps and can potentially be adapted as light source of an UV-based AOP. In the present work, a PL/H 2 O 2 process was tested for the decolourization of two azo dyes, and a pulsed light/H 2 O 2 /ferrioxalate process was tested for the decolourization of one azo dye. The efficiency of the PL/H 2 O 2 process in a batch reactor under different parametric values: dye concentration, pH, H 2 O 2 and salt doses was followed by spectrophotometry and fitted to first-order kinetics; and several degradation products were detected. In the PL/H 2 O 2 process, decolourization rates increased at low dye concentrations and high H 2 O 2 doses, were pH-dependent and were inhibited by the addition of NaCl, Na 2 SO 3 or Na 2 CO 3. More than 50% decolouration was achieved with the PL/H 2 O 2 process for both dyes after applying 54 J/cm 2 (25 light pulses). The PL/H 2 O 2 /ferrioxalate process achieved >95% decolouration for Methyl orange when applying 21 J/cm 2 (10 pulses); that level of energy can be supplied by PL commercial systems in nine and four seconds respectively. No known toxic degradation products were detected. Results show that a PL/H 2 O 2 process has potential to be used for the efficient degradation of dyes from wastewater. Furthermore, the efficacy of this process can be improved by the use of ferrioxalate. PL technology could become an alternative light source to contribute to decrease the environmental impact of wastewater produced by the dyeing industry. © 2019 |
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