Absorption of NOx up to partial pressures of 500 Pa was experimented at 20 degrees C and atmospheric pressure with aqueous and nitric acid solutions containing hydrogen peroxide. Various NOx oxidation ratios in the gas phase, and different concentrations of nitric acid and hydrogen peroxide in the scrubbing liquid were investigated. It was shown that the absorption rate was enhanced by H2O2 but remains constant if increasing excess quantities of H2O2 are used. Absorption of NOx into H2O2 is considerably catalyzed by nitric acid. A mathematical model was developed in which all these experimental observations were included, and overall kinetic parameters for different NOx species were determined. Favorable agreement was shown between the model predictions and the experimental results obtained both in a laboratory-scale and a pilot-scale absorption column.