Electrodialysis unit (EDU) is using for desalting brackish water, drinking water, water treatment in processes of production, regulating the concentration of brines and much more.
Electrodialysis modules is a hardware filter-press type, consists of two repeated sections: the concentrate (brine) and demineralization section (desalination). Before switching DC all sections of electrodialyzer uniformly filled by cations and anions of the electrolyte (serum, in this case,). When the DC is switched on, the cations migrate through the cation membrane to the cathode, however, further electromigration to the cathode limited permeability for them anionic membrane. Accordingly, the anions in the presence of a constant electricity currently migrate to the anode through anonic membrane, but further electromigration, to prevent the anode cation membrane that little permeable to anions. The result is a symmetric process in which cations and anions from the even-numbered sections called desalting partitions, migrating to the odd, where they accumulating, and sections called partitions concentrate (brine).
The main directions of application of electrodialysis.
Purification of non-electrolytes from mineral impurities:
• Clean from salt solutions and aqueous mixtures of organic compounds and substances: serum, amino acids, vitamins, milk;
• sugar, molasses and intermediates for their production;
• juice, latex, photographic emulsions, cellulose pulp, black liquor.
• Demineralization of glycerol, organic acids, monomers, intermediates in organic synthesis.
• Cleaning milk from radioactive elements.
Treatment of water and aqueous solutions of electrolytes:
• Desalination solutions of electrolytes.
• Reduced wastewater (production of ammonium nitrate, electroplating, etching household).
• Preparation of water to heat.
• Cleanup of radioactive wastewater.
Concentration of solutions:
• The concentration of wastewater containing valuable components (a rare and precious metals for subsequent retrieval), solutions of salts of uranium.
• Conversion of waste carbonate-sulfate solutions.
• The concentration of electrolyte solutions before residue.
• The concentration of radioactive water.
• Obtaining of acid and alkali salts of, for example, NaOH and formic cyclotis of sodium formiate; Zola silicic acid from sodium silicate; Hydrobromic acid from ammonium bromide.
• Regeneration of acids from the acidic etching solutions using electrodialysis plants.
The fractionation processes:
• Department of multivalent cations from monovalent.
• Division of protein hydrolysates on the amino acid fraction; separation of amino acids.
• Changing the ionic composition of the fluid, for example, the ratio of CA:PA in milk.
Application in the dairy industry
Currently, necessity, desirability and feasibility of industrial processing whey have no doubt among professionals in the dairy industry all over the world.
As a byproduct of processing milk, whey has a high nutritional and biological value (which contains about 50% solids milk proteins, vitamins and minerals) at low energy values (in serum goes a small amount of milk fat).
Such a unique product properties open up broad prospects for its application in various industries:
In that case, the dumping of whey drains is not only the factor of environmental pollution, but also lost profits from the loss of a promising resource.
Low using of serum in industrial processing caused by a high content of minerals and lactic acid. However, modern technology demineralization of whey allow you to easily solve this problem.
One of the leading tendency recent years in conversation of serum in our country and abroad is the widespread use of membrane processing techniques, particular - electrodialysis.