Electrodialysis main industrial applications

This membrane industry is very fragmented. Industrial applications are divided into six main sub-groups reverse osmosis ultrafiltration microfiltration gas separation pervaporation and electrodialysis. Medical applications are divided into three more artificial kidneys blood oxygenators and controlled release pharmaceuticals. Few companies are involved in more than one sub-group of the industry. Because of these divisions it is difficult to obtain an overview of membrane science and technology this book is an attempt to give such an overview. 

Electrodialysis is now a mature technology, with Ionics remaining the worldwide industry leader except in Japan. Desalting of brackish water and the production of boiler feed water and industrial process water were the main applications until the 1990s, but electrodialysis has since lost market share due to stiff competition from improved reverse osmosis membranes. Beginning in the 1990s,... 

This review summarizes the monopolar and BPM principles of operation. Moreover, this review presents shortly the main applications in chemical processing, pollution control, and resource recovery, and details the specific applications of electrodialysis with BPMs to food and bio-industries. 

Ion exchange membranes have been used in various industrial fields, and have great potential for use in new fields due to their adaptable polymer membrane. As mentioned in the Introduction, membranes are characterized mainly by ion conductivity, hydrophilicity and the existence of carriers, which originate from the ion exchange groups of the membrane. Table 6.1 shows reported examples of applications of ion exchange membranes and the membrane species used in various fields. Various driving forces are usable for separation electrochemical potential, chemical potential, hydraulic pressure such as piezodialysis and pervaporation, temperature difference (thermo-osmosis), etc. Of these, the main applications of the membrane are to electrodialysis, diffusion dialysis, as a separator for electrolysis and a solid polymer electrolyte such as in fuel cells. 

The technically and economically most important electrodialytical process used for the separation of ionic components from an aqueous solution is conventional electrodialysis. The main application of electrodialysis is the desalination of brackish water. However, other uses, especially in the food, drug, and chemical process industry as well as in biotechnology and waste water treatment, have recently gained a broader interest. In its basic form electrodialysis can be utilized to perform several general types of separations, such as the separation and concentration of salts, acids, and bases from aqueous solutions, or the separation of monovalent ions from multiple charged components, or the separation of ionic compounds from uncharged molecules. 

This paper covers mainly the industrial and medical applications of electrodialysis, ultrafiltration and microfiltration rather than those of reverse osmosis, which have been covered by many authors elsewhere. 

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