ABSTRACT

Flocculation plays a key role in several natural processes in the aquatic and marine environment such as sediment erosion, transport, aggregation and deposition and it is often employed in several industrial purification and separation processes. A number of interfacial forces and interactions that play key roles in flocculation process are well-understood in the light of classical and extended DLVO theory, and therefore it provides a basis for any theoretical analysis of particle dispersion and colloidal stability. Flocculation kinetics deal with time-dependent changes in the dispersion or suspension and provides information on the flocculation rate, dispersion stability and particle interactions which depends on the number and efficiency of the particle collisions. In most practical applications of flocculation, the aggregation processes typically occur under turbulent conditions. The energy barrier to flocculation can be overcome in several other ways apart from the kinetic energy derived from the transport mechanisms.