Expression characteristics of polyelectrolyte flocculated sludges
Journal
Journal of the Chinese Institute of Chemical Engineers
Journal Volume
31
Journal Issue
4
Pages
321-331
Date Issued
2000
Author(s)
Chu C.P.
Abstract
This work investigates how polyelectrolyte flocculation affects the dewatering efficiency of activated sludge and ball clay slurry. Although the activated sludge is much more difficult to dewater than the clay slurry, polyelectrolyte flocculation markedly enhances the dewatering efficiency of both sludges, with the maximum improvement occurring at the charge neutralization point. Flocculation yields a stiff cake structure and transforms the major dewatering mechanisms from primary to secondary consolidation. The creeping of particles in the sludge is enhanced since the presence of flocculant molecules causes moisture to be expelled from the solid surface. This moisture loss reduces the total consolidation time and diminishes the tertiary consolidation stage in the activated sludge, which is advantageous to dewatering.This work investigates how polyelectrolyte flocculation affects the dewatering efficiency of activated sludge and ball clay slurry. Although the activated sludge is much more difficult to dewater than the clay slurry, polyelectrolyte flocculation markedly enhances the dewatering efficiency of both sludges, with the maximum improvement occurring at the charge neutralization point. Flocculation yields a stiff cake structure and transforms the major dewatering mechanisms from primary to secondary consolidation. The creeping of particles in the sludge is enhanced since the presence of flocculant molecules causes moisture to be expelled from the solid surface. This moisture loss reduces the total consolidation time and diminishes the tertiary consolidation stage in the activated sludge, which is advantageous to dewatering.
Subjects
Bound Water
Consolidation
Creeping Factor
Filtration
Specific Resistance
Type
journal article