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Remediation and Treatment Technology Development and Support. Raul Dominguez Guillermo Brailly Mentor: Prabhakar Pant Florida International University Miami, FL. Agenda. Background Task Assigned Research on Mercury Speciation Laboratory Support Documentation Future Work Conclusion.
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Remediation and Treatment Technology Development and Support Raul Dominguez Guillermo Brailly Mentor: Prabhakar Pant Florida International University Miami, FL
Agenda • Background • Task Assigned • Research on Mercury Speciation • Laboratory Support • Documentation • Future Work • Conclusion
Background • Mercury contamination at the Oak Ridge National Laboratory. The study of Mercury concentration in soil samples collected from the Oak Ridge National Laboratories is important because it will help the analysis of the Total Maximum Daily Load (TMDL) as required by the U.S. Environmental Protection Agency (USEPA) and National pollutant discharge elimination system (NPDES).
Background • Uranium contamination at the Hanford National Laboratory. The Hanford site lies beside the Columbia River. During WWII and the Cold War the Hanford site was used to create uranium fuel for the production of plutonium for the nations weapons program. The site is still contaminated to this day. The contaminants were expected to dissipate naturally, but they haven’t. This project is of high importance because by understanding the fate and transport of the uranium, where it goes, where it comes from, how much of it will attach to soil, and how much will dissolve into ground water, we will be able to prevent any further contamination.
Task Assigned • Research on Mercury Speciation • Fractionation • Methods of Extraction Hg • Laboratory Support • Soil Sample Processing • Documentation • Table of the properties of Mercury.
Fractionation • Evaluate whether Hg concentration and speciation in this soil sample was affected by soil composition • Redoximorphic depletions and concentrations were manually separated. RD was grey and RC was brownish. • Abundant RC also contained higher concentrations of Fe, Mn, Ca, and Mg • Split in two, one sample stored in freezer and the other freeze dried for 72 hours
Fractionation • Dried samples were then ground with a mortar • Coarse(500 μm) and fine particles (250 μm) seperated by No. 35 and No. 60 sieves. • To determine later if particle size has correlation with Hg concentration.
Methods of Extraction of Hg Sequential extraction • Can be utilized for a wide variety of environmental soil samples • Separate mercury compounds into 5 different compound classes, shown in Figure 1 • These classes, and the more common mercury compounds predicted to be included in each class, are shown in Table 1
Methods of Extraction of Hg Thermal Desorption • Uses heat to physically separate the contaminants from the soil. • Temperatures of 200-1,000 degrees F, contaminants with low boiling points will vaporize or turn into gas and separate from the soil. • Post-treatment system for both the gas contaminants and the remaining soil
Laboratory Support • Task #8: Soil Sample processing 1) The soil samples are kept frozen, in order to prevent any lose of Hg. Refrigeration keeps microorganism in the soil from turning the inorganic Hg into elemental Hg.
Laboratory Support 2) The samples are labeled to distinguish the depth and exactly where at Oak Ridge the samples were collected. This sample is labeled “MB E-10ft(M2)” 3) The samples retain a lot of moister during the refrigeration process, as can be seen by the ice in the soil. 4) When working with different samples I changed my gloves in between each sample to prevent errors caused by cross contamination.
Laboratory Support 5) If the samples get heated they begin to lose mercury. There fore we placed the samples in large beakers and set them to dry in a air sentry. 6) Paper towels were placed over the samples to prevent cross contamination.
Laboratory Support 7) In order to obtain accurate results the samples must be homogenized thoroughly, after being air dried properly. 8) Once the samples have been homogenized they are taken back to the lab for analysis with the Direct Mercury Analyzer.
Laboratory Support Soil samples set to dry on January 28, 2008 • 2 1000mL beakers of soil sample MC3C E-10ft approximation. • 1 600mL beaker of MA5C height approximation 10ft. • 1 1000mL beaker of MB2C • 1 1000mL beaker of MA1C • 1 1000mL beaker of MC3opp.C
Documentation Chemical Properties of Mercury
Future Work • Mercury contamination at the Oak Ridge National Laboratory. • My mentor has been working on a new system that will allow us to air dry more samples, faster and more efficiently with less possibilities of cross contamination. • Uranium contamination at the Hanford National Laboratory • More research on Uranium contamination at Hanford will be completed. • Soil work with Uranium will be conducted. • A table of the radioactive properties of Uranium will be developed
Reference • Liu, G., Cabrera, J., Allen, M. and Cai, Y.(2006).メMercury characterization in a soil sample collected nearby the DOE Oak Ridge Reservation utilizing sequential extraction and thermal description method.モ, Science of Total Environment 369, 384-392 • U.S. EPA. "Speciation of Mercury in Soils by Sequential Extraction." [Online] <http://www.epa.gov/nerlesd1/pdf-ecb/542asd95.pdf>. • U.S. EPA, " EPA Technology Fact Sheet: EPA 542-F-96-005." [Online] < www.epa.gov/tio/download/remed/inntech.pdf >. • 1. http://www.nyenvirolaw.org/PDF/Shiue-4-24-02-MercuryMemo.pdf • 2. Environmental health & Safety, Material Safety Data Sheet www.jtbaker.com/msds/englishhtml/ml547.htm • 3. International labour organization, International occupation safety health information centre (CIS) http://www.ilo.org/public/english/protection/safework/cis/products/icsc/ dtasht/_icsc09/icsc0982.htm • 4. International safety Cards, http://www-old.itcilo.org/actrav/actrav- english/telearn/osh/ic/7783359.htm • 5. Australia Government Department of the Environmental Water Resources. http://www.npi.gov.au/database/substance-info/profiles/53.html • 6. California Poison Control System (CPCS) and Regents, University of California 2000- 2006 www.calpoison.org/public/mercury.html
Recognition THANKS to:Dr. Leonel Lagos - ARC, Prabhakar Pant - ARC and my partner.