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EMERGING TECHNOLOGY SUMMARY: REMOVAL AND RECOVERY OF METAL IONS FROM GROUNDWATER
Citation:
U.S. EPA. EMERGING TECHNOLOGY SUMMARY: REMOVAL AND RECOVERY OF METAL IONS FROM GROUNDWATER. U.S. Environmental Protection Agency, Washington, DC, EPA/540/S5-90/005, 1990.
Impact/Purpose:
to inform the public
Description:
A series of bench-scale tests and an onsite pilot scale demonstration of Bio-Recovery Systems' AlgaSORB® technology for the removal and recovery of mercury-contaminated groundwaters were conducted under the SITE program. The AlgaSORB® process is based on the natural, very strong affinity of biological materials, such as the cell walls of plants and microorganisms, for heavy metal ions. Biological materials, primarily algae, have been immobilized in a polymer to produce a "biological" ion exchange resin called AlgaSORB®. The material has a remarkable affinity for heavy metal ions and is capable of concentrating these ions by a factor of many thousandfold. Additionally, the bound metals can be stripped and recovered from the algal material in a manner similar to conventional resins. This new technology has been demonstrated to be an effective method for removing toxic metals from groundwaters. Metal concentrations can be reduced to low parts per billion (ppb) levels. Optimum conditions were determined for binding mercury to AlgaSORB®. Conditions under which mercury could be stripped from AlgaSORB® were also developed. Onsite, pilot-scale demonstrations with a portable waste treatment system incorporating columns containing two different AlgaSORB® preparations confirmed laboratory tests. Over 500 bed volumes of mercury-contaminated groundwater could be successfully treated before regeneration of the system was required. Mercury was removed to levels below the discharge limit of 10 mg/L.