AWWA JAW10519

In addition to some theoretical considerations, this article presents data from experiments in which alum sludges, a lime sludge, and polymer-conditioned alum sludges were characterized. An attempt was made to correlate the sludge characteristics with observed sludge dewatering characteristics. Relationships between floc microproperties, such as size and density, and observed dewatering characteristics produced by sand bed and mechanical dewatering devices are examined. Floc properties such as size distribution and density showed a significant effect on both the rate and extent of dewatering obtained when water plant sludges were treated by mechanical filtration equipment. Polymer addition improved sludge dewatering rates but did not significantly affect cake solids concentrations, compressibility, or sludge handling characteristics. Includes 15 references, tables, figures.