Electrolysis with diamond anodes: Eventually, there are refractory species!

In this work, synthetic wastewater polluted with ionic liquid 1-butyl-3-methylimidazolium (Bmim) bis(trifluoromethanesulfonyl)imide (NTf2) undergoes four electrolytic treatments with diamond anodes (bare electrolysis, electrolysis enhanced with peroxosulfate promoters, irradiated with UV light and w...

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Detalles Bibliográficos
Autores: Cotillas, Salvador, Sáez Jiménez, Cristina, Fernández Mena, Ismael, Díaz, Elena, Rodríguez Jiménez, Juan José, Cañizares Cañizares, Pablo, Fernandez Mohedano, Ángel, Rodrigo Rodrigo, Manuel Andrés
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/17556
Acceso en línea:https://doi.org/10.1016/j.chemosphere.2017.12.120
https://hdl.handle.net/10578/17556
Access Level:acceso abierto
Palabra clave:Refractory
Ionic liquid
Bis(trifluoromethanesulfonyl)imide
1-Butyl-3-methylimidazolium
Electrolysis
Descripción
Sumario:In this work, synthetic wastewater polluted with ionic liquid 1-butyl-3-methylimidazolium (Bmim) bis(trifluoromethanesulfonyl)imide (NTf2) undergoes four electrolytic treatments with diamond anodes (bare electrolysis, electrolysis enhanced with peroxosulfate promoters, irradiated with UV light and with US) and results obtained were compared with those obtained with the application of Catalytic Wet Peroxide Oxidation (CWPO). Despite its complex heterocyclic structure, Bmim+ cation is successfully depleted with the five technologies tested, being transformed into intermediates that eventually can be mineralized. Photoelectrolysis attained the lowest concentration of intermediates, while CWPO is the technology less efficient in their degradation. However, the most surprising result is that concentration of NTf2- anion does not change during the five advanced oxidation processes tested, pointing out its strong refractory character, being the first species that exhibits this character in wastewater undergoing electrolysis with diamond. This means that the hydroxyl and sulfate radicals mediated oxidation and the direct electrolysis are inefficient for breaking the C-S, C-F and S-N bounds of the NTf2- anion, which is a very interesting mechanistic information to understand the complex processes undergone in electrolysis with diamond.