Removal kinetic model of oil droplet from o/w emulsion by adding methylated milk casein in flotation.

In this study, o/w emulsion flotation experiments were conducted by adding methylated milk casein (MeSC). Emulsion used in this study was prepared by ultrasonic emulsification of heavy oil (bunker-A) and sodium dodecyl sulfate (SDS) solution. A simple kinetic model was proposed to estimate the removal rate of the oil droplets within the column. The model was based on main assumption that adsorption of single droplet adsorbed MeCS or floc onto bubble surface within flotation column. Removal rate constant, K, was defined by k(a)X(s) (S(b)τ/V), where k(a) and X(s) are overall adsorption rate and saturated adsorption density of oil droplet or floc, S(b), τ and V are bubble surface production rate, retention time of bubble swarms and emulsion volume within the column, respectively. The experiments were conducted with varying operating conditions; superficial gas velocity, column dimension and emulsion volume. K was evaluated from slope value of obtained straight line by plotting time versus ln (T/T(0)), where T/T(0) is relative turbidity. K was mostly proportional to (S(b)τ/V), which corresponds to specific surface area of bubble swarms per unit volume within the column, in the present experimental region. This result suggested that efficiency of this removal process was mainly controlled by the specific surface area of bubble swarms, and proposed model was fundamentally verified.