Electrochemical incineration of cresols: a comparative study between PbO2 and boron-doped diamond anodes.
The electrooxidation of aqueous solutions containing 5mM of o-, m- and p-cresol at pH 4.0 has been investigated using a flow filter-press reactor with a boron-doped diamond (BDD) under galvanostatic electrolysis. All cresols are degraded at similar rate up to attaining overall mineralization. Comparable treatment of the m-cresol effluent on PbO(2) leads to partial electrochemical incineration. However, this pollutant is more rapidly removed with PbO(2) than with BDD. The decay kinetics of all cresols follows a pseudo-first-order reaction. Aromatic intermediates such as 2-methylhydroquinone and 2-methyl-p-benzoquinone and carboxylic acids such as maleic, fumaric, pyruvic, malonic, tartronic, glycolic, glyoxylic, acetic, oxalic and formic, have been identified and followed during the m-cresol treatment by chromatographic techniques. From these oxidation by-products, a plausible reaction sequence for m-cresol mineralization on both anodes is proposed. The energy consumption for the corresponding electrochemical process is also calculated.
Flox
Cristina
C
Departament de Química Física, Facultat de Química, Laboratori d'Electroquímica dels Materials i del Medi Ambient, Universitat de Barcelona, Martí i Franquès 1-11, Barcelona, Spain.
Arias
Conchita
C
Brillas
Enric
E
Savall
André
A
Groenen-Serrano
Karine
K
D001895:Boron / Q000737:chemistry*; D003408:Cresols / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D017745:Incineration; D007854:Lead / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*
D003408:Cresols; D010087:Oxides; D007854:Lead; C047365:lead oxide; D018130:Diamond; D001895:Boron