Abstract
The adsorption rate of surfactant ion in foam separation technique was experimentally studied. By using SDBS (sodium dodecylbenzene sulphonate) as surfactant and NaCl as coexisting salt, foam separation experiments in a continuous-flow foam column were carried out, and following facts were obtained.
It was found that there was a large amount of surface excess of DBS- at the liberation of bubbles from a sparger. In a non-salt system (SDBS solution), the adsorption rate equation of Langmuir''s type could be well applied to the adsorption of DBS-, in the region of bulk concentration of DBS- in which the Langmuir adsorption isotherm can be applied. In the case of 0.17-0.19 cm of bubble diameter, surface excess of DBS- attained to an adsorption equilibrium within one second, and the apparent adsorption rate became more rapid than that in the case of 0.06-0.07 cm of bubble diameter. Moreover, the adsorption rate increased more than that in a non-salt system, by the addition of NaCl.
