Introduction of a new flocculation control factor based on kinetics and fractal dimension concept

Abstract:

Conventional flocculation kinetics based on velocity gradient law has several theoretical and applicable drawbacks.In this study,force analysis on flocs in turbulent flows was carried out and the results suggest that the vortex within characteristic scale is crucial in flocculation process,and the inertia effect of micro vortex causes the collision and aggregation of flocs.According to analysis of influenced factors on kinetic mass transfer and morphology of flocs,it is verified that the density of flocs is proportional to shear strength,whereas the strength of flocs presents inverse proportional correlation to shear strength.Furthermore,a new flocculation control factor defined as F r0is proposed based on kinetic and fractal morphology analysis.It is the modification of conventional flocculation control theory and provides a reference for practical design.