The increasingly automated industrial processes are responsible for a large part of the generation of oily effluents, which present great difficulty of treatment due to the complexity of removal of fine particles of oil. The application of biosurfactants and the dimensionless number of Damköhler (Da) in a prototype of dissolved air flotation (DAF) allowed predictions of efficiency of oil removal in oily waters. Two different biosurfactants were used in order to confirm a first-order kinetic law for the DAF process in the water-oil separation. The kinetic behavior of the DAF process was associated by analogy with a perfect blending reactor (Continued Stirred Tank Reactor – CSTR). In this way, a laboratory float was used in order to allow experiments with the biosurfactants produced by the bacteria Bacillus sp. and Pseudomonas aeruginosa. A first-order kinetic model was fitted to the experimental data, using Quasi-Newton numerical optimization methods The application of the dimensionless number of Damköhler, together with the use of the biosurfactants, allowed prediction of the oil removal efficiency, around 90%. It has been observed that it is also possible to predict the flotation chamber volume based on a desired value of removal efficiency.