Ion Exchange

 

Typical ion exchangers are ion exchange resins (functionalized porous or gel polymer) and zeolites. Ion exchangers are either cation exchangers that exchange positively charged ions (cations) or anion exchangers that exchange negatively charged ions (anions). There are also amphoteric exchangers that are able to exchange both cations and anions simultaneously. However, the simultaneous exchange of cations and anions can be more efficiently performed in mixed beds that contain a mixture of anion and cation exchange resins, or passing the treated solution through several different ion exchange materials.

 

EDI is a process that combines semi-impermeable membrane technology with ion-exchange media to provide a high efficiency demineralization process.

 

Electrodialysis employs electrical current and specially-prepared membranes which are semi permeable to ions based on their charge, electrical current, and ability to reduce the ions based to their charge. Through electrodialysis an electrical potential transports and segregates charged aqueous species. The electrical current is used to continuously regenerate the resin, eliminating the need for periodical regeneration.