Investigation of the products of oxidation of methylpyridines under aqueous conditions by gas chromatography–mass spectrometry

Abstract

Wet air oxidation is a waste treatment process known to break down organic compounds at elevated temperatures and pressures under aqueous conditions. We have investigated, by gas chromatography–mass spectrometry, the products arising from the wet air oxidation of 2-, 3- and 4- methylpyridines carried out in a laboratory autoclave. The results indicate that radical chemistry is responsible for the products. The oxidation of each of the methylpyridines by use of Fenton's reagent was also studied, because this is known to generate hydroxyl radicals. Similarities were observed between products generated by Fenton-catalysed oxidations carried out in the laboratory and the uncatalysed autoclave reactions. Further experiments, where Fenton's reagent was incorporated in the laboratory autoclave reactions, were carried out. An improved level of decomposition of the methylpyridines was achieved by the incorporation of a hydroxyl radical-producing catalyst.