A new method for assessment of the sludge disintegration degree with the use of differential centrifugal sedimentation

A novel method for assessing the disintegration degree (DD) of waste activated sludge (WAS) with the use of differential centrifugal sedimentation method (DCS) was shown herein. The method was validated for a WAS sample at four levels of disintegration in the range of 14.4-82.6% corresponding to the median particle size range of 8.5-1.6 mu m. From the several sludge disintegration methods used (i.e. microwave, alkalization, ultrasounds and peroxydisulfate activated by ultrasounds), the activated peroxydisulfate disintegration resulted in the greatest DD 83% and the smallest median particle size of WAS. Particle size distribution of pretreated sludge, measured by DCS, was in a negative correlation with the DD, determined from soluble chemical oxygen demand (SCOD; determination coefficient of 0.995). Based on the obtained results, it may be concluded that the DCS analysis can approximate the WAS disintegration degree.
WAS disintegration, differential centrifugal sedimentation, disintegration degree, chemical oxygen demand, sludge particle size