(160o) Design of an Electrochemical Adsorption Cell with under Control Particles Deposition

Deposition of colloidal particles substrate is encountered in a variety of naturally occurring processes such as particulate fouling of heat exchangers, thrombus formation in vascular prostheses and other artificial organs and aerosols entering the lungs. Deep bed filtration of waste waters is perhaps the most prominent example of importance to industry. Design of an electrochemical adsorption cell utilizing reticulated vitreous carbon (R. V.C.) as the working electrode ,stainless steel as the counter electrode and a cellulose acetate membrane ,for separating the anodic and cathodic, is described for the separation of 5.4 m polystyrene latex colloidal particles from a KCI solution. The experimental results are compared with the Derjaguin-Landau-Verwey-Ovdrbeek (D.L.V.O.) prediction for the occurrence of favorable and unfavorable deposition conditions. In the theoretical section of this work it will be assumed that the main energies contributing adsorption interaction between the surfaces will be due to electrical double layer to Van der Waals attraction . The some of these energies provides the total interaction energy between surfaces and this constitutes the underlying assumption for the classical D.L.V.O. theory of colloidal stability. In this way , for the present experimental conditions the main forces contributing to deposition process are the surface forces and hydrodynamics . At the highest flow rate of 34 cm 3 / min 1 the colloidal forces were shown to be negligible compared to the hydrodynamics . Indeed the effect of surface at the KCI concentration of 0.001 mol/dm3 apparently only became significant at flow rate of 1.7 cm 3 / min 1 . At this flow rate and KCI concentration of 0.001 mol / dm3 experimental results show Clear evidence of conditions governing the of favorable and unfavorable deposition conditions . The variation of collector potential under unfavorable deposition condition does not produce large changes in the deposition rate whereas variation collector potential under favorable condition produce significant change in the deposition state.