SciTech Connect

Title: Selective sorption of technetium from groundwater

Selective sorption of technetium from groundwater Groundwater used for processing uranium or plutonium at DOE sites is frequently contaminated with the radionuclide {sup 99}Tc. DOE`s Paducah and Portsmouth sites are typical of the contamination problem. Solutions contaminated with radionuclides were poured into lagoons and burial pits, which created a plume that has seeped into the sandy aquifers below the vadose zone. Technetium is the principal radioactive metal-ion contaminant in Paducah site ground-water, and it is present at a concentration of about 25 ng/L. At Portsmouth, Tc is present in the groundwater at a concentration that varies greatly with distance from the source, and concentrations of >400 ng/L have been reported. Commercially available anion-exchange resins can remove the TcO{sub 4}{sup {minus}} ion in the presence of typical anions found in groundwater, but improving the selectivity will result in substantial cost savings in terms of the quantity of resin needed and the scale of the equipment required to treat huge flows rates. The pertechnetate anion is strongly sorbed on commercially-available strong-base anion-exchange resins, but in view of the low (typically nanomolar) concentrations of Tc involved, enhanced selectivity for the pertechnetate anion over other anions commonly found in groundwater such as chloride, sulfate, and nitrite will be needed. The more » authors have prepared and evaluated new anion-exchange resins that were designed to be highly selective for pertechnetate. The technology involves building those features that are known to enhance the selectivity of pertechnetate over other anions into the exchange sites of the resin (hydrophobicity), while at the same time maintaining favorable exchange kinetics. « less
Authors:
Publication Date:
OSTI Identifier:527190
Report Number(s):PNNL-SA--28461-Rev.1; CONF-970148--Rev.1
ON: DE97052111; TRN: 97:015033
DOE Contract Number:AC05-96OR22464
Resource Type:Conference
Data Type:
Resource Relation:Conference: Efficient Separations and Processing (ESP) Crosscutting Program FY 1997 technical exchange meeting, Gaithersburg, MD (United States), 28-30 Jan 1997; Other Information: PBD: [1997]; Related Information: Is Part Of Proceedings of the efficient separations and processing crosscutting program 1997 technical exchange meeting; Gephart, J.M. [ed.]; PB: 211 p.
Research Org:Science, Inc., Anaheim, CA (United States)
Country of Publication:United States
Language:English
Subject: 54 ENVIRONMENTAL SCIENCES; GROUND WATER; REMEDIAL ACTION; TECHNETIUM 99; SORPTION; PERTECHNETATES