Title
Insights into solar photo-Fenton process using iron(III)-organic ligand complexes applied to real textile wastewater treatment
Date Issued
05 April 2015
Access level
metadata only access
Resource Type
journal article
Author(s)
Manenti D.
Soares P.
Módenes A.
Boaventura R.
Bergamasco R.
Vilar V.
West Paraná State University
Publisher(s)
Elsevier B.V.
Abstract
The treatment of a real textile wastewater was accomplished using a conventional photo-Fenton reaction and mediated by different ferric-organic ligand complexes, performed in lab and pilot scale photoreactors irradiated by simulated and natural solar radiation, respectively. The textile wastewater presents a dark-blue colour, alkaline pH, a high organic content (COD=1239mgO2L-1; DOC=408mgCL-1) and moderate biodegradability (BOD5/COD=0.16). The conventional solar-photo-Fenton reaction showed limited efficiency in the mineralization of the textile wastewater, which is characterized by a fast initial dissolved organic carbon decay in the absence of light, mainly attributed to the formation of iron-organic pollutants complexes with a low solubility at acidic pH values, leading to iron precipitation, followed by a very slow reaction rate under UV-visible light associated to (i) low amounts of dissolved iron and (ii) low photoactivity of the iron precipitates. The addition of the organic ligands, such as oxalic acid, citric acid and EDDS, enhanced significantly the photo-Fenton reaction, avoiding the formation of iron-organic pollutants complexes, and consequently increase of the quantum yield for ferrous ions production through the photodecarboxylation of ferric-organic ligands complexes. The catalytic activity of the iron-organic ligand complexes increased in the following order: Fe(III)-EDDS<Fe(III)-citrate<Fe(III)-oxalate. All the tested processes mediated by ferric-organic ligands complexes contributed to an effective decolourization and mineralization, but the most efficient system was the photo-Fenton-ferrioxalate reaction with an optimum catalyst concentration of 100mgFe3+L-1, pH 2.8, temperature of 30°C leading to complete decolourization and 69.1% mineralization after less than 8.8kJUVL-1. An enhancement of the wastewater biodegradability was observed during the photo-Fenton-ferrioxalate reaction.
Start page
203
End page
212
Volume
266
Language
English
OCDE Knowledge area
Ingeniería química
Scopus EID
2-s2.0-84922567571
Source
Chemical Engineering Journal
ISSN of the container
1385-8947
Sponsor(s)
This work was supported by projects PEst-C/EQB/LA0020/2013 and NORTE-07-0162-FEDER-000050, financed by FEDER through COMPETE – Programa Operacional Factores de Competitividade, by FCT – Fundação para a Ciência e a Tecnologia and by QREN and ON2. We also thank the Araucaria Foundation for financial support of this study. Diego R. Manenti and Petrick A. Soares acknowledge their Ph.D. fellowships (BEX 9794/11-5 and 5512/10-7 processes) supported by CAPES. V.J.P. Vilar acknowledges the FCT Investigator 2013 Programme (IF/01501/2013). Aparecido N. Módenes and Fernando R. Espinoza-Quiñones thank to CNPq and CAPES for financial support.
Sources of information: Directorio de Producción Científica Scopus