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Permeable Reactive Barrier FeasibilityLos Alamos, NMSource: The following text was excerpted from project summary information provided by representatives of Los Alamos National Laboratory, April 2001 Project Summary: The following text was excerpted from project summary information provided by representatives of Los Alamos National Laboratory, April 2001: Groundwater in Mortandad Canyon at Los Alamos National Laboratory, Los Alamos, NM, is being treated using a Multi-Barrier technology that consists of four different layers of materials arranged as a Permeable Reactive Barrier (PRB). Among the targeted contaminants is perchlorate. The perchlorate in the groundwater results from the use of perchloric acid in the chemical oxidation and dissolution of plutonium and other actinides during processing and analysis. Removal of perchlorate from process wastewater has not been attempted until recently, resulting in a plume of the highly-mobile perchlorate anion in groundwater emerging from the discharge point in Mortandad Canyon. Treatment to remove perchlorate from LANL wastewater was initiated when the EPA and other agencies clearly identified it as an emerging and wide-spread concern in the nation's groundwaters, and as the health effects were shown to be of concern as a risk to human health. The contaminated groundwater that exists in Mortandad Canyon is the subject of in situ treatment using our PRB technology. The perchlorate removal mechanism in the LANL Multi-Barrier is through microbial reduction to harmless chloride ions. The Multi-Barrier uses two layers that provide biological activity sufficient to reduce perchlorate to non-detectable levels. Both of these layers are made from inexpensive waste materials. Both hydroxyapatite obtained as fishbone, and a carbon-based support material (pecan shell waste) are capable of supporting the growth of a microbial biofilm that is highly effective at reducing both nitrate, the primary contaminant targeted in this groundwater, and perchlorate to non-detectable levels as the groundwater flows through the barrier. Both materials also serve other purposes in the system, primarily radionuclide and metal removal processes. Laboratory studies have been performed using both batch and column systems, as well as a 2-dimensional mock-up of a full-scale Multi-Barrier system. The groundwater used in these tests is from a single well, MCO-5 in Mortandad Canyon. The perchlorate concentration in this well at the time of sampling was about 350 ppb. These results have been or will be reported at several national and international conferences in early 2001, and are to be published in a book chapter. The Multi-Barrier is also targeted at removal of actinidecontaminated colloidal particles, soluble actinides and metals, and other minor biodegradable wastewater contaminants such as organic nitrogen and carbon compounds (VOC/SVOCs). A field-scale system will be installed in Mortandad Canyon in the fall of 2001 at a site downstream from the discharge point for the LANL Radioactive Liquid Waste Treatment Facility, an NPDES-permitted surface water discharge outfall (see PERC0051). This project is a field-scale demonstration of the Multi-Barrier system that will have multiple sampling points at strategic locations in each layer, and at points above and below the barrier. It will be used to provide data on the efficacy of the approach, and on the persistance of the barrier materials over long time periods. The barrier is expected to perform the groundwater cleanup function for 10 years or more, and will be sampled periodically throughout this period for characterization of the groundwater and to document performance. The materials will also be sampled periodically to assess their persistance and to analyze changes in material structure and composition, and in microbial population composition with time. Additional Info Source: B.A. Strietelmeier, M.L. Espinosa, M.W. Jones, J.D. Adams, E.M. Hodge, S.D. Ware, P.A. Leonard, P. Longmire, J.P. Kaszuba and J.L. Conca, 2001, Remediation of Nitrate-Contaminated Groundwater Using a Biobarrier, Environmental Science and Waste Technology Division, Facilities and Waste Operations Division, and Earth and Environmental Systems Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, proceedings from the Waste Management 2001 Conference, Tucson, AZ, March-April 2001. Taylor, T.P. and N.N. Sauer, 2000, Remediation of Inorganic Contaminated Groundwater Using Multi-Barrier Reactive Treatment Wall Technology, Gordon Research Conference, Modeling of Flow in Permeable Media, Andover, NH. Habas, S.E., T.P. Taylor, N.N. Sauer, J.L. Conca, B.A. Strietelmeier, J.P. Kaszuba, M.L. Espinosa and S.D. Ware, 2000, Multiple Reactive Barrier Wall Technology for Remediation of Inorganic Contaminated Groundwater, Robert A. Laudise, ACS Symposium, Union College, NY. T P. Taylor, B.A. Strietelmeier, S.D. Ware, M.L. Espinosa, N.N. Sauer, J.L. Conca, 2001, Use of Novel Reactive Barrier Materials for Treatment of Strontium, Uranium, Nitrates and Perchlorates in Groundwater, Los Alamos National Laboratory, Los Alamos, NM 87545, to be presented at the 2001 International Containment & Remediation Technology Conference and Exhibition in Orlando, FL, June 10-13, 2001. (Abstract accepted) B.A. Strietelmeier, M.L. Espinosa, J.D. Adams, P.A. Leonard and E.M. Hodge, 2001, Use of a Unique Biobarrier to Remediate Nitrate and Perchlorate in Groundwater, Los Alamos National Laboratory, Los Alamos, NM 87545, to be presented at the 2001 International Containment & Remediation Technology Conference and Exhibition in Orlando, FL, June 10-13, 2001. (Abstract accepted) T.P. Taylor, N.N. Sauer, J.L. Conca, B.A. Strietelmeier, J.P. Kaszuba, M.W. Jones and S.D. Ware, 2001, Reactive Barrier Treatment Wall Technology for Remediation of Inorganic Contaminated Groundwater, Los Alamos National Laboratory, Los Alamos, NM 87545, USA, to be presented at the Groundwater 2001 conference, Sheffield, England. (Abstract accepted) J. Conca, E. Strietelmeier, N. Lu, S.D. Ware, T.P. Taylor, J. Kaszuba and J. Wright, 2001, Remediation of Groundwater Contaminated with Radionuclides, Metals and Nitrates Using a Four-Component Permeable Reactive MultiBarrier - Treatability Study and Field Design, Los Alamos National Laboratory, Los Alamos, NM 87545, UFA Ventures, Inc., Richland, WA 99352, submission to book entitled "Handbook of Groundwater Remediation of Trace Metals, Radionuclides, and Nutrients with Permeable Reactive Barriers," D. Naftz, S.J. Morrison, J.A. Davis and C.C. Fuller, editors, due fall 2001 from Academic Press, San Diego, CA. (In preparation) D. Krier, J. Kaszuba, J. Conca, P. Longmire, E. Strietelmeier and D. Meadows, 2001, A Multiple Permeable Reactive Barrier Installation at Los Alamos National Laboratory, NM: Progress Report, Los Alamos National Laboratory, Los Alamos, NM 87545 and The IT Group, Los Alamos, NM 87544, to be presented to the Association of Engineering Geologist annual meeting, St Louis, MO, September, 2001. (Abstract submitted) |
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