Comparative degradation of indigo carmine by electrochemical oxidation and advanced oxidation processes

ABSTRACT: The remediation of aqueous effluents containing indigo carmine (IC), a highly toxic indigoid dye used as a textile coloring agent and an additive in pharmaceutical tablets and capsules, was studied using four promising technologies: Ultrasound (US), photo-Fenton (PF), TiO2 photocatalysis (...

Descripción completa

Detalles Bibliográficos
Autores: Palma Goyes, Ricardo Enrique, Silva Agredo, Javier, González, Ignacio, Torres Palma, Ricardo Antonio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Colombia
Institución:Universidad de Antioquia
Repositorio:Repositorio UdeA
Idioma:inglés
OAI Identifier:oai:bibliotecadigital.udea.edu.co:10495/13349
Acceso en línea:http://hdl.handle.net/10495/13349
Access Level:acceso abierto
Palabra clave:Dyes
Electrochemical oxidation
Indigo Carmine
Photo-Fenton
Water treatment
Índigo carmín
Tintes
Tratamiento de aguas
Descripción
Sumario:ABSTRACT: The remediation of aqueous effluents containing indigo carmine (IC), a highly toxic indigoid dye used as a textile coloring agent and an additive in pharmaceutical tablets and capsules, was studied using four promising technologies: Ultrasound (US), photo-Fenton (PF), TiO2 photocatalysis (TiO2/UV) and electrochemical oxidation with Ti/IrO2-SnO2-Sb2O5 as anode (EO). The main degradation pathway was determined for each system tested. Additionally, the comparative effects of initial pH and presence of chloride ions was investigated. The results showed that EO of IC was mediated by chloride, whereas IC degradation by TiO2/UV occurred directly in valence band holes of the catalyst. However, with PF and US systems hydroxyl radicals OH played the main role. In spite of the different degradation pathways, acidic pH increased the performance of all systems. The presence of chloride favored the efficiency of EO, but inhibited the IC removal by PF, as well as the elimination of Chemical Oxygen Demand (COD) by US and TiO2/UV. The results showed that, under working conditions, EO with Ti/IrO2-SnO2-Sb2O5 anodes is the best option to treat IC in effluents containing a significant concentration of chloride ions