New insights into the mechanism of Fered-Fenton treatment of industrial wastewater with high chloride content: Role of multiple reactive species
Hydroxyl radical (¿OH) is considered the dominant reactive species in the electro-Fenton (EF) and Fered-Fenton (EFFere) processes for wastewater treatment. However, in chloride-rich media, this is arguable due to the obscure mechanisms for the oxidant speciation and pollutant degradation. Herein, th...
| Autores: | , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/199403 |
| Acceso en línea: | https://hdl.handle.net/2445/199403 |
| Access Level: | acceso abierto |
| Palabra clave: | Clorurs Electroquímica Contaminants Chlorides Electrochemistry Pollutants |
| Sumario: | Hydroxyl radical (¿OH) is considered the dominant reactive species in the electro-Fenton (EF) and Fered-Fenton (EFFere) processes for wastewater treatment. However, in chloride-rich media, this is arguable due to the obscure mechanisms for the oxidant speciation and pollutant degradation. Herein, the role of active chlorine and Fe(IV)-oxo species (FeIVO2+) as primary oxidizing agents in HClO-mediated Fered-Fenton (EF-Fere-HClO) process is discussed, along with the dependence of their contribution on the pollutant structure. HClO generated from anodic oxidation of Cl− can be consumed by added H2O2 to form singlet oxygen (1O2), which is detrimental because this species is quickly deactivated by water. The reaction between HClO and Fe2+ was proved to generate FeIVO2+, rather than ¿OH or Cl¿ suggested in the literature. The yield of FeIVO2+ species was proportional to the Cl− concentration and barely affected by solution pH. The long-lived HClO and FeIVO2+ can selectively react with electron-rich compounds, which occurs simultaneously to the non-selective attack of ¿OH formed from Fenton's reaction. The FeIVO2+ and ¿OH concentration profiles were successfully modelled. Although the accumulation of toxic chlorinated by-products from HClO-mediated oxidation might cause newenvironmental concerns, the toxicity of pesticide wastewater with 508mMCl− was halved upon EF-Fere-HClO treatment. |
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