Ion Exchange

Description

Ion exchange is a remediation process that removes dissolved metals from liquids. An ion is an atom or group of atoms that has lost an electon (making it positively charged) or gained an electron (making it negatively charged). Liquids are passed over a resin bed where ions (i.e., cations and anions) in the resins and in contaminated materials are exchanged. The resins attract the metallic ions. After the resin capacity has been exhausted, resins can be regenerated for re-use.

Limitations and Concerns

Oil and grease in the groundwater may clog the exchange resin.

The acidity or alkalinity of the incoming water may limit ion exchange capability. This can usually be controlled.

Oxidants in groundwater may damage the ion exchange resin.

Wastewater is generated during the regeneration step and requires additional treatment and disposal.

Applicability

Ion exchange can remove dissolved metals and radionuclides from a contaminated liquids. It is used in a variety of purposes, including >ex-situ remediation of groundwater and processing of mixed liquids wastes from storage tanks.

Technology Development Status

This technology has long been used in industry and is commercially available.

Web Links

http://www.lgst.com/matrix/section4/4_52.html

Other resources

None have been identified.