GRAVITATIONAL SEDIMENTATION OF FLOCCULATED WASTE ACTIVATED SLUDGE

This paper reported the spatio-temporal gravitational settling characteristics of activated sludges using Computerizes axial Tomography Scanner. The tests with kaolin slurries were conducted for comparison. The settling velocity for the waste activated sludge was much lower than the kaolin slurries. The transient settling for the investigated activated sludges was described using the plastic rheological model by Buscall and White. flocculation would produce a lower yield stress. Therefore, althrough the flocculated sludge was tougher than the original sample in the final sediment, the latter was more compressible than the former in the transient settling stage.