No abstract

An isopyenic centrifugation procedure was developed for estimating the characteristic floe 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 floe 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 floe structure. Water Environ. Res., 65, 735 (1993).