Removal of imidazolium-based ionic liquid by coupling Fenton and biological oxidation

In this work, we assessed the potential of combining Fenton´s reagent and biological oxidation for removing the imidazolium-based ionic liquid 1-Ethyl-3-methylimidazolium chloride (EmimCl). Fenton-like oxidation was conducted at variable H2O2 doses from 20 to 100% the stoichiometric value as calcula...

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Detalles Bibliográficos
Autores: Gómez Herrero, Esther, Tobajas Vizcaíno, Montserrat, Polo Díez, Alicia Marta, Rodríguez Jiménez, Juan José, Fernández Mohedano, Ángel
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/711417
Acceso en línea:http://hdl.handle.net/10486/711417
https://dx.doi.org/10.1016/j.jhazmat.2018.10.097
Access Level:acceso abierto
Palabra clave:Biodegradability
Biological treatment
Ecotoxicity
Fenton-like oxidation
Ionic liquid
Ingeniería Industrial
Química
Descripción
Sumario:In this work, we assessed the potential of combining Fenton´s reagent and biological oxidation for removing the imidazolium-based ionic liquid 1-Ethyl-3-methylimidazolium chloride (EmimCl). Fenton-like oxidation was conducted at variable H2O2 doses from 20 to 100% the stoichiometric value as calculated from the theoretical chemical oxygen demand (COD). The stoichiometric H2O2 dose afforded Total Organic Carbon (TOC) conversion and COD removal of 50 and 62%, respectively. Identifying the reaction by-products formed at low hydrogen peroxide doses allowed a plausible pathway for EmimCl oxidation to be proposed. The effluents from Fenton-like oxidation at substoichiometric H2O2 doses were less ecotoxic and more biodegradable than was the parent ionic liquid. The effluent from Fenton-like oxidation with the 60% H2O2 dose (TOC conversion ≅ 41%, COD removal ≅ 31%) was subsequently subjected to an effective biological treatment that allowed complete removal of the starting compound, increased its ecotoxicity to a low–moderate level and rendered it acceptably biodegradable. Biological oxidation was performed in 8-h and 12-h cycles in a sequencing batch reactor. Combining Fenton and biological oxidation of EmimCl afforded TOC conversion and COD removal of around 90%