Predicting Fenton-driven degradation using contaminant analog

The reaction of hydrogen peroxide (H2O2) and Fe(II) (Fenton's reaction) generates hydroxyl radicals (.OH) that can be used to oxidize contaminants in soils and aquifers. In such environments, several factors can limit the effectiveness of chemical oxidation, including reactions involving H2O2 that do not yield .OH, .OH reactions with nontargeted chemicals, and insufficient iron in the soil or aquifer. Consequently, site-specific studies may be necessary to evaluate the feasibility of chemical oxidation using H2O2. Here, the degradation of a contaminant analog, alpha-(4-pyridyl-1-oxide) N-tert-butylnitrone (4POBN), was used to estimate .OH concentration and simplify testing procedures. A kinetic model was developed, calibrated using 4POBN degradation kinetics, and used to predict the disappearance of 2-chlorophenol (2CP), a representative target. Good agreement between predicted (Y) and measured (X) values for 2CP (Y = 0.95X) suggests that the kinetics of analogs degradation can be used to predict the degradation rate of compounds for which the rate constant for reaction with .OH is known.