Electro–oxidation of industrial wastewater containing 1,4-dioxane in the presence of different salts

The treatment of 1,4-dioxane solution by electrochemical oxidation on boron-doped diamond was studied using a central composite design and the response surface methodology to investigate the use of SO42- and HCO3- as supporting electrolytes considering the applied electric current, initial COD value...

Descripción completa

Detalles Bibliográficos
Autores: Barndok, Helen, Hermosilla Redondo, María Daphne, Cortijo, Luis, Torres, Esperanza, Blanco Suárez, María Ángeles
Tipo de recurso: artículo
Fecha de publicación:2014
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/33914
Acceso en línea:https://hdl.handle.net/20.500.14352/33914
Access Level:acceso abierto
Palabra clave:628.3
66.0
Electro-oxidation
1
4-dioxane
Boron doped diamond
Biodegradability
Pseudomonas putida
Central composite
Agua
Ingeniería química
Química industrial
Residuos
2303.31 Química del Agua
3303 Ingeniería y Tecnología Químicas
Descripción
Sumario:The treatment of 1,4-dioxane solution by electrochemical oxidation on boron-doped diamond was studied using a central composite design and the response surface methodology to investigate the use of SO42- and HCO3- as supporting electrolytes considering the applied electric current, initial COD value, and treatment time. Two industrial effluents containing bicarbonate alkalinity, one just carrying 1,4-dioxane (S1), and another one including 1,4-dioxane and 2-methyl-1,3-dioxolane (S2), were treated under optimized conditions, and subsequently subjected to biodegradability assays with Pseudomonas putida culture. Electro-oxidation was compared with ozone oxidation (O3) and its combination with hydrogen peroxide (O3/H2O2). Regarding the experimental design, the optimal compromise for maximum COD removal at minimum energy consumption was shown at the maximum tested concentrations of SO42- and HCO3- (41.6 and 32.8 mEq•L-1, respectively), and the maximum selected initial COD (750 mg•L-1), applying a current density of 11.9 mA•cm-2 for 3.8 hours. Up to a 98% of the COD was removed in the electro–oxidation treatment of S1 effluent using 114 kWh per kg of removed COD; and about a 91% of the COD from S2 wastewater applying 49 kWh per kg of removed COD. The optimal biodegradability enhancement was achieved after 1 h of electro-oxidation treatment. In comparison with O3 and O3/H2O2 alternatives, electrochemical oxidation achieved the fastest degradation rate per oxidant consumption unit; as well as it also resulted to be the most economical treatment in terms of kWh consumption and price per unit of removed COD.