DEGRADATION KINETICS OF FORMIC ACID IN WATER SOLUTION EMPLOYING THE PHOTO-FENTON REACTION

摘要

The Fenton reaction is a chemical system involving hydrogen peroxide and ferrous salts that generates highly reactive hydroxyl radicals at low temperature; these radicals react rapidly and non selectively with most toxic organic compounds (Zepp et al., 1992; Bigda, 1995). A modern application of this reaction is the degradation of pollutants that may be present in water and wastewater streams. The oxidation ability of the Fenton mixture can be greatly enhanced using UV or UV/visible radiation (the light-enhanced Fenton or the photo-Fenton reaction) in order to increase the production rate of hydroxyl radicals (Rupper and Bauer, 1993; Pignatello and Sun, 1995). In this study the photodegradation of a specific organic pollutant (formic acid) in aqueous solution, using the photo-Fenton system, has been modeled and experimentally verified. It must be noted that two parallel reactions must be taken into account: (ⅰ) the Fenton (thermal) reaction and (ⅱ) the photo-Fenton (light activated) reaction. This is particularly important when the reaction volume is not equal to the photoreactor volume.