THE DENSITY OF PARTICLE AGGREGATES

Aggregates of particles formed in coagutation/flocculation processes v ery often have a fractal, self-similar structure, with the very import ant practical consequence that the effective density of aggregates dec reases as their size increases. This has very significant effects on s eparation processes such as sedimentation, notation and filtration. Th e fundamental factors which influence the density of aggregates (flocs ) are reviewed, with a discussion of the effects on aggregate size dis tribution, the rate of formation of flocs and their capture by collect ors. Several experimental methods for determining flee density are cri tically examined. (C) 1997 IAWQ. Published by Elsevier Science Ltd.