Electrodialysis

Electrodialysis is the method of purification of liquid dispersed systems (colloidal solutions, suspensions and other, and also solutions of high-molecular substances, such as proteins) from impurities of low-molecular substances, dissolved in the dispersive environment. Electrodialysis is based on the acceleration of diffusion of ions through the membrane under the influence decent electric field. Electrodialyzer usually consists of three consecutive chambers, separated validazione membranes; in the middle is the feed solution, in the side - distilled water. In the side branches fortified electrodes connected to the poles of a constant current source. As the anode use materials which are not soluble in the conditions of electrolysis, such as platinum graphite or charcoal. During electrodialysis solution, located in the middle division, molten glass mixer. Sometimes in electrodialyzers applied concentric arrangement of cameras. Electrodialysis solutions substances, oxidizing in the air, carried out in the atmosphere of inert gases. Over the course of electrodialysis is monitored by measuring the conductivity is obtained by electrodialysis solution (electrodialysis) or the concentration of electrolytes. Great importance in the electrodialysis has the choice of material membranes. Depending on the surface charge and other terms they can be prepared so that they are easily missed ions carrying a charge of one sign, and were virtually impenetrable for ions with a charge of opposite sign. Membrane easily passing cations, set near the cathode; membrane is selectively permeable for anions,near the anode. Method of electrodialysis is widely used in biochemical studies with a clean (and highlight) proteins, hormones, antibiotics and other biologically active substances. Electrodialysis is used in the production for cleaning the protein solutions, dyes, tannins and Sometimes use other devices in which the electrodialysis combine with ultrafiltration (see) (electrolatrine). Cm. also Dialysis.