The kinetics of nonylphenol and p-cresol destruction by hydrogen peroxide photolysis and Fenton's reaction was investigated under a variety of operating conditions in homogeneous, laboratory-scale batch reactor experiments. Models with no adjustable parameters successfully accounted for radical initiation by photolysis of H2O2 or radical initiation by Fenton's mechanism, reaction of organic targets with hydroxyl radical, and radical scavenging and recombination mechanisms, as well as changes in solution pH due to evolution of carbon dioxide because of target mineralization. Simulations of the UV/H2O2 and Fenton-based models can be used to anticipate the kinetics of advanced oxidation involving any target compound for which there is a known apparent second-order rate constant for reaction with hydroxyl radical. The presence of radical scavengers was successfully treated by the model, suggesting that the model can be generalized to the treatment of complex matrixes.