Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, I.R. IRAN
The effects and influences of various parameters upon the efficiency and the overall volumetric mass transfer coefficients are important subjects to be studied in most liquid-liquid extraction processes. One of these important parameters is surface active agent (surfactant). In this paper, in order to study the effect of sodium dodecyl sulfate (SDS) concentration on the efficiency and the average overall volumetric mass transfer coefficients, several experiments were carried out in a ten stage mixer-settler. In these experiments the effect of surfactant concentration on above mentioned parameters at constant operational conditions are studied. In general the efficiency and mass transfer coefficients dropped significantly at low surfactant concentration and remained almost constant at the higher concentrations (Almost a minimum point was observed). Although the surfactant caused a decrease in mass transfer, but the amount of mass transfer coefficients in both phases are considerable and therefore the resistance against mass transfer in both phases cannot be neglected.