The disintegration of waste active sludge was investigated by photo-Fenton processes. A batch study was conducted to evaluate parameters, such as Fe2+ and Fe-0 ions and H2O2, governing the activated sludge integration by the photo-Fenton process. Under optimum conditions, the concentration of soluble chemical oxygen demand (SCOD) with the classical Fenton process (CFP) increased very rapidly in the first five minutes due to the sufficient presence of reaction components in the medium, and then the rate of increase declined. In the modified Fenton process (FTP), the SCOD concentration increased more slowly as metallic iron powder must first be dissolved. The photo-Fenton process proved to be a feasible and efficient process for the disintegration of waste sludge.