Network strength of waste activated sludge using rheological tests

Abstract

A rheogram of waste activated sludge is used to estimate the non-Newtonian behavior of original and flocculated flocs. The shearing energy, input by the rheometer, represents the plastic contribution of the floc network strength. This study estimated the binding strength of network flocs in waste activated sludge from rheological tests. Two sludge samples from a wastewater treatment plant were considered. The binding strength increased with polymer dose, indicating the structure's higher resistance to hydrodynamic shear. Although the Es value could not be used as a single index for comparing the ease of dewatering various batches of sludge, it can be used for online monitoring to flocculation status for sludge.