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Mineralization of Catechol by Fenton and Photo‐Fenton Processes
Author(s) -
M'hemdi Asma,
Dbira Bechir,
Abdelhedi Ridha,
Brillas Enric,
Ammar Salah
Publication year - 2012
Publication title -
clean – soil, air, water
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 66
eISSN - 1863-0669
pISSN - 1863-0650
DOI - 10.1002/clen.201100376
Subject(s) - mineralization (soil science) , chemistry , catechol , aqueous solution , oxalic acid , muconic acid , formic acid , fenton reaction , nuclear chemistry , acetic acid , radical , organic chemistry , benzene , nitrogen
Abstract Catechol is one of the most abundant phenolic components of olive mill wastewaters. In this article, the mineralization of this compound in synthetic aqueous solutions by the Fenton and photo‐Fenton processes is studied. It has been found that for 1.44 mM catechol, the total organic carbon of solutions is reduced about 94.4% at best after 60 min of Fenton treatment at optimized conditions of pH 3.0, 0.2 mM Fe 2+ , 7.09 mM H 2 O 2 , and 25°C. A faster and overall mineralization is attained by applying photo‐Fenton with UVA irradiation. o ‐Benzoquinone, 1,2,3‐trihydroxybenzene and 1,2,4‐trihydroxybenzene were identified by GC–MS as primary quinonic and polyhydroxylated derivatives. Small amounts of generated carboxylic acids like muconic, maleic, malonic, acetic, oxalic, and formic acids were detected by ion‐exclusion chromatography. The Fe(III) complexes of these acids persist in the medium under Fenton conditions, while their photolysis by UVA light and that of other by‐products account for by the faster degradation and total mineralization achieved in the photo‐Fenton process. A reaction sequence for catechol mineralization by Fenton and photo‐Fenton involving all intermediates detected is proposed.