Effect of straggling parameters in the separation of oil in wastewater: Application in flotation columns.

Wastewaters of the Oil Company Tron Hnos. S. A. from C. V. (Morelia, Mich. Mexico) contain vegetable oils (corn, ajonjoli, soya, heliotrope), in proportions between 40% and 50% v/v, that form stable emulsions with the aqueous phase. In this work, the results of the experimental study about the separation of wastewater oils by flotation in laboratory columns are presented. The results of this research show that the recuperation of the organic compounds is 60% v/v in only one flotation stage; but considering series of 2, 3, and 4 columns, oil recuperations increase towards 90%, 95% and 97% v/v, respectively. The experiments showed that there is a lineal correlation between flotation kinetics and the parameters that determine the straggling effect. Besides, this study suggests that there is an optimum size of the bubbles, where oil recuperations are highest. This works shows that the application of flotation columns for oils separation in water is becoming very important.