In this research study, the effectiveness of ultrasound pre-treatment on the solubilization of two different waste activated sludges (WAS1 and WAS2) was investigated by batch tests in order to improve their anaerobic digestion biodegradability. A physical, chemical and biological characterization of sludges was performed at different specific energy inputs. Moreover, sludge anaerobic biodegradability was tested at different F/I ratios and biogas production was also predicted by respirometric tests.
