Measurement of chemical sludge floc density and implications related to sludge dewatering

Abstract

ABSTRACT: An isopyenic centrifugation procedure was developed for estimating the characteristic floc density present in several chemical sludges. Issues addressed included selection of a low osmotic pressure gradient medium; selection of appropriate centrifugal acceleration and time values for testing; viscosity effects; and need for temperature control. Increases in sludge floc density were predictive of an increase in cake solids concentration following mechanical dewatering. Most sludge water removal during dewatering was hypothesized to be external to the floc structure.