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What is the principle of desalination by electrodialysis in Laboratory Electrolyzer
Electrodialysis is a transfer process of solution separation, purification and concentration by utilizing the selective permeability of Laboratory Electrolyzer ion exchange membranes under the action of a DC electric field to generate directional migration of anions and cations. Electrodialysis technology is a kind of membrane separation technology. It arranges anion and cation exchange membranes alternately between positive and negative electrodes, and separates them with special separators to form two systems of desalination (desalination) and concentration. Under the action of DC electric field, the potential difference is used as the driving force, and the selective permeability of the ion exchange membrane is used to separate the electrolyte from the solution, so as to realize the concentration, desalination, purification and purification of the solution.
Electrodialysis electrodes in Laboratory Electrolyzer are divided into several types: titanium platinum-coated electrodes, titanium-coated ruthenium electrodes, graphite electrodes, and stainless steel electrodes; the electrodes have different design specifications according to the size of the electrodialyzer. The correct selection of electrode materials is of great significance to prolong the service life of electrodes, reduce system investment and operating costs, and choose electrodes of different materials for different water quality:
(1) For chlorides as the main component, titanium-coated ruthenium electrodes can be used.
(2) For those with sulfate as the main component, lead plates and titanium-coated iridium-tantalum-coated electrodes can be used.
(3) For calcium bicarbonate as the main component, titanium-coated ruthenium electrodes can be used.
(4) For mixed ions, titanium-coated ruthenium-iridium, iridium-tantalum, titanium-plating and graphite electrodes can be used.