Sonication pretreatment of sludge: preliminary study of operation parameters

Abstract

The objective of this work was to investigate effects of some key operation parameters serving sludge ultrasonication (US). First, a stirrer speed of 500 rpm was found to be convenient for sludge US pretreatment. A slight decrease in sludge US pretreatment efficacy due to the erosion of the probe surface was observed. Apart from DD_COD increase as a result of sludge floc disruption, apparent viscosity decreased as a function of ES during US pretreatment. Finally, sequential isothermal US showed significant improvement of sludge disintegration in some cases, especially at high US power and pressure.