Electrodialysis
Electrodialysis is an electro-membrane process in which direct electric field drives the movement of dissociated components of salts in aqueous solution so that cations moving towards the cathode are transmitted through cation-exchange membranes and held by anion-exchange membranes, while anions attracted towards the anode are transmitted through anion-exchange membranes and held on cation-exchange membranes.
By a proper combination of cation- and anion-exchange membranes, ions in the inflow solution are separated, generating the desalinated strem called the diluate and the concentrated stream called the concentrate. This separation is achieved due to the influence of electric field and on the basis of different permselectivity of ion-exchange membranes for individual components in the solution. By both electrodes, so-called electrode solution circulated (usually a solution of indifferent salt or inflow treated solution), washing their surface regularly and not participating in the electrodialysis separation.
The goal of electrodialysis can be acquiring products of one type of solution only (diluate or concentrate); however, in some cases there are quality requirements concerning both products (especially in waste water treatment), e.g. when the diluate must meet criteria for being released into the watercourse and the concentrate must have the best possible parameters for further processing.
Electrodialysis utilization
in water treatment
- desalination of brackish and surface water
- purification of mine water
- water desalination after tertiary biological treatment
in industry
- purification of waste water from galvanic baths
- purification of waste water in fertilizer production
- separation of inorganic and organic solutions
- purification of organic substances
in food-processing industry
- demineralization of whey
- stabilization of wine
in pharmacy
- purification of fermentation solutions
- purification of sera and vaccines
MemBrain s.r.o. offers
- development of electrodialysis modules – optimization of individual module components
- development of technological layout of electrodialysis
- based on the client’s needs, we perform laboratory or pilot verification tests to find out the electrodialysis process suitability
