A new method for calculation of flocculation kinetics combining Smoluchowski model with fractal theory

In this study, the widely applied modified Smoluchowski model of flocculation kinetics based on the existence of two simultaneous processes, namely aggregation and breakup, is further developed by combining it with the fractal theory. The floc properties including the floc size and fractal dimension are extracted using online data acquisition through light scattering technique and combined into the model. The new method has been carefully examined by three flocculation systems using kaolin suspension as synthetic water and different typical flocculants. The theoretic flocculation kinetic curves are in good agreement with the experimental data with the determination coefficients larger than 0.9 by nonlinear regression. Moreover, the flocculation kinetic characteristics of different flocculation systems under various conditions are discussed based on the kinetic rates calculated from the modified model in detail. In summary, the new method for calculation of flocculation kinetics is more universal and simpler to operate, and is expected to be a useful tool in real water treatment operations.