Effects of an electric or magnetic field on the radiolytic degradation of two biorefractory contaminants, Acid Orange 7 (AO7) and nitrobenzene (NB), were evaluated in this work. A continuous DC electric current with a low density (similar to 2.8-5.6 mA cm(-2)) applied during the radiolytic degradation of AO7 and NB solutions only led to slight enhancement in their degradation rate constants, but altered significantly the degradation mechanisms. On the other hand, application of a magnetic field (0.4 T) in irradiation processes slightly enhanced the degradation kinetics without leading to any change in degradation mechanisms. (c) 2004 Elsevier B.V. All rights reserved.