Physical Aspects of Flocculation

Abstract

This article discusses a mathematical relation that describes the kinetics of flocculation. It takes into account flocculating time and intensity, coagulant dose, and volume and solids content of the floc. This relation indicates that the entrapment of suspended matter by floc is influenced by the volume of floc produced rather than by the size or appearance of floc particles. Jar test data confirm the hypothesis that floc volume is proportional to the coagulant dosage used and further indicate that floc can be made ten times more compact by extended agitation dose, and volume and solids content of the floc. This relation indicates that the entrapment of suspended matter by floc is influenced by the volume of floc produced rather than by the size or appearance of floc particles. Jar test data confirm the hypothesis that floc volume is proportional to the coagulant dosage used and further indicate that floc can be made ten times more compact by extended agitation (Gt = 200,000) than by limited agitation (Gt = 10,000), without impairing its settling characteristics.