Impact of Inherent Factors on the Radiolytic Degradation of Biorefractory Contaminants

Experiments were carried out to gain insight into the effect of inherent factors on the radiolytic degradation of two biorefractory contaminants, Acid Orange 7 (AO7) and nitrobenzene (NB). The effects of irradiation dose rate (Dr), initial substrate concentration (C0), pH, and temperature of solutions were evaluated in terms of degradation kinetics, degradation efficiency, initial G values of substrate decomposition, and total organic carbon reduction. Higher C0 and lower Dr values were favorable for the efficient utilization of radiation energy, whereas higher Dr and lower C0 levels were beneficial for degradation rate. An increase in pH led to a reduction in degradation rate constant or degradation efficiency. The temperature of solutions had different effects on the radiolytic degradation of AO7 and NB. The degradation of AO7 followed the empirical Arrhenius law, whereas an increase in temperature led to a reduction in the degradation of NB.