Kinetics Model of Destabilization of Oil Droplets in Oily Wastewater Emulsions

In this article, a mathematical model that accounts for the kinetics of flocculation and coalescence of emulsion drops was developed to quantify the kinetics of emulsion stability. The model is similar to that developed by Borwankar et al. in 1992 with corrections in coalescence rate constant and collision efficiency factor. It includes a term to describe efficiency of collisions. Also, the coalescence rate constant was defined as a function of the total number of particles that were present in the system at the moment. The model has four adjustable parameters, and nonlinear least square optimization is used to obtain the adjustable parameters. The obtained adjustable parameters by the model served as parameters that can be used to quantitatively evaluate the effectiveness of a set of different demulsifiers by measuring total numbers of drops versus time and by determining the adjustable parameters and comparing them. The results of the presented model and the model of Borwankar et al. were compared with experimental data. The results of the new model were in good agreement with experimental data and showed the model's ability for dispalying the behavior of droplets during the destabilization processes of emulsions.