The Removal of Anionic Surfactant Using Multistage Foam Separation Equipment

Abstract

The following study deals with the equipment design of a foam separation technique used for removal of an anionic surfactant, sodium dodecylbenzenesulfonate, from its aqueous solution. This technique eliminates the use of the bubble size parameter which is difficult to control and measure. Two possible methods are feasible in the design of a multistage foaming equipment. One is similar to the multistage concurrent ion exchanger design which takes account of the interrelationships of experimental surface excess equilibrium, bubble diameter and foamate, while the other method which this paper presents is based on the interrelationships of the foamate concentration, the foamate and pool concentration under a given experimental equipment. In this study, the latter method which the bubble diameter is included as an implicit function proves to be preferable to the former because here the surface excess depends on the pool depth and the bubble diameter which is also a weak function of the bulk concentration.
For this study, a 4-stage foaming equipment was utilized which was operated under the optimum gas flow rates, and discrepancies between the calculated and experimental values were found to be small.