skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on November 19, 2019

Title: Pertechnetate (TcO4−) sequestration from groundwater by cost-effective organoclays and granular activated carbon under oxic environmental conditions

Abstract

Technetium-99 (Tc-99) is a major risk driver at nuclear power plants and several US Department of Energy (DOE) sites. Pertechnetate (TcO4-), the most common chemical form present in liquid nuclear waste and the environment, displays limited adsorption onto sediments, making it highly mobile and difficult to immobilize. In this work, inexpensive organoclays and granular activated carbon (GAC) were investigated for TcO(4)(- )sequestration from artificial groundwater (AGW). The Tc adsorption capacities were 15 mg/g for organoclays and 25 mg/g for GAC from pH 3-12 AGW under oxic conditions. Competitive NO3- at two orders of magnitude greater concentration than TcO4- reduced the Tc adsorption capacity by only 9-25%. In addition, the adsorbed Tc was effectively desorbed by KI, but not Na2SO4, and the regenerated sorbents retained their Tc removal capacity. X-ray absorption spectroscopy demonstrated that the Tc species bound to the organoclays and GAC was Tc(VII) (i.e., TcO4-), rather than Tc(IV). Thus, the inexpensive organoclays and GAC are highly effective at sequestering Tc-99 in its naturally existing TcO4- without requiring costly reductive systems, which may provide a practical solution for removing (TcO4-)-Tc-99 from environmental systems.

Authors:
ORCiD logo; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States); Savannah River Site (SRS), Aiken, SC (United States); Univ. of Georgia, Aiken, SC (United States)
Sponsoring Org.:
USDOE Office of Environmental Management (EM); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); SRNL Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1512416
Alternate Identifier(s):
OSTI ID: 1510257
Report Number(s):
SRNL-STI-2018-00137
Journal ID: ISSN 1385-8947; 146810
Grant/Contract Number:  
AC02-06CH11357; AC09-08SR22470; FC09-07SR22506
Resource Type:
Accepted Manuscript
Journal Name:
Chemical Engineering Journal
Additional Journal Information:
Journal Volume: 360; Journal Issue: C; Journal ID: ISSN 1385-8947
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
Synchrotron XANES and EXAFS; granular activated carbon; organoclays; pertechnetate; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; synchrotron XANES and EXAFS

Citation Formats

Li, Dien, Seaman, John C., Kaplan, Daniel I., Heald, Steve M., and Sun, Chengjun. Pertechnetate (TcO4−) sequestration from groundwater by cost-effective organoclays and granular activated carbon under oxic environmental conditions. United States: N. p., 2019. Web. doi:10.1016/j.cej.2018.11.146.
Li, Dien, Seaman, John C., Kaplan, Daniel I., Heald, Steve M., & Sun, Chengjun. Pertechnetate (TcO4−) sequestration from groundwater by cost-effective organoclays and granular activated carbon under oxic environmental conditions. United States. doi:10.1016/j.cej.2018.11.146.
Li, Dien, Seaman, John C., Kaplan, Daniel I., Heald, Steve M., and Sun, Chengjun. Fri . "Pertechnetate (TcO4−) sequestration from groundwater by cost-effective organoclays and granular activated carbon under oxic environmental conditions". United States. doi:10.1016/j.cej.2018.11.146.
@article{osti_1512416,
title = {Pertechnetate (TcO4−) sequestration from groundwater by cost-effective organoclays and granular activated carbon under oxic environmental conditions},
author = {Li, Dien and Seaman, John C. and Kaplan, Daniel I. and Heald, Steve M. and Sun, Chengjun},
abstractNote = {Technetium-99 (Tc-99) is a major risk driver at nuclear power plants and several US Department of Energy (DOE) sites. Pertechnetate (TcO4-), the most common chemical form present in liquid nuclear waste and the environment, displays limited adsorption onto sediments, making it highly mobile and difficult to immobilize. In this work, inexpensive organoclays and granular activated carbon (GAC) were investigated for TcO(4)(- )sequestration from artificial groundwater (AGW). The Tc adsorption capacities were 15 mg/g for organoclays and 25 mg/g for GAC from pH 3-12 AGW under oxic conditions. Competitive NO3- at two orders of magnitude greater concentration than TcO4- reduced the Tc adsorption capacity by only 9-25%. In addition, the adsorbed Tc was effectively desorbed by KI, but not Na2SO4, and the regenerated sorbents retained their Tc removal capacity. X-ray absorption spectroscopy demonstrated that the Tc species bound to the organoclays and GAC was Tc(VII) (i.e., TcO4-), rather than Tc(IV). Thus, the inexpensive organoclays and GAC are highly effective at sequestering Tc-99 in its naturally existing TcO4- without requiring costly reductive systems, which may provide a practical solution for removing (TcO4-)-Tc-99 from environmental systems.},
doi = {10.1016/j.cej.2018.11.146},
journal = {Chemical Engineering Journal},
number = C,
volume = 360,
place = {United States},
year = {2019},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 19, 2019
Publisher's Version of Record

Save / Share: