A5016499476- Mercury impact and mitigation studies
- Radioactive element chemistry and processing
- Heavy metals in environment
- Toxic Organic Pollutants Impact
- Chemical Synthesis and Characterization
- Radioactive contamination and transfer
- Analytical chemistry methods development
- Marine animal studies overview
- Marine and coastal ecosystems
- Water Quality and Pollution Assessment
- Extraction and Separation Processes
- Geochemistry and Elemental Analysis
- Water Quality and Resources Studies
- Water Treatment and Disinfection
- Heavy Metal Exposure and Toxicity
- Geology and Paleoclimatology Research
- Environmental Toxicology and Ecotoxicology
- Marine and fisheries research
- Radioactivity and Radon Measurements
- Isotope Analysis in Ecology
- Nuclear Materials and Properties
- Electrochemical Analysis and Applications
- Covalent Organic Framework Applications
- Groundwater and Isotope Geochemistry
- Fish Ecology and Management Studies
Pacific Northwest National Laboratory
2014-2023
Olympic Medical Center
2014
Battelle
2008
Texas A&M University at Galveston
1998-2007
California Department of Fish and Wildlife
2007
Moss Landing Marine Laboratories
2007
University of Washington
1978-2004
Alcoa (United States)
1998
University of Ottawa
1997
Texas A&M University
1992-1995
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSubnanogram determination of mercury by two-stage gold amalgamation and gas phase detection applied to atmospheric analysisWilliam F. Fitzgerald Gary A. GillCite this: Anal. Chem. 1979, 51, 11, 1714–1720Publication Date (Print):September 1, 1979Publication History Published online1 May 2002Published inissue 1 September 1979https://pubs.acs.org/doi/10.1021/ac50047a030https://doi.org/10.1021/ac50047a030research-articleACS PublicationsRequest reuse...
Uranium recovery from seawater has been investigated for several decades the purpose of securing nuclear fuel energy production. In this study, field column experiments have performed at Marine Sciences Laboratory Pacific Northwest National (PNNL) using a laboratory-proven, amidoxime-based polymeric adsorbent developed Oak Ridge (ORNL). The was packed either in in-line filters or flow-through columns. maximum amount uranium uptake 3.3 mg U/g after 8 weeks contact between and seawater. This...
A new family of high-surface-area polyethylene fiber adsorbents named the AF series was recently developed at Oak Ridge National Laboratory (ORNL). The were synthesized by radiation-induced graft polymerization acrylonitrile and itaconic acid (at different monomer/comonomer mol ratios) onto high surface area fibers. degree grafting (%DOG) found to be 154–354%. grafted nitrile groups converted amidoxime treating with hydroxylamine. amidoximated then conditioned 0.44 M KOH 80 °C followed...
Sediment depth profiles of total mercury (THg) and monomethylmercury (MMHg) were collected at 15 sites in an anthropogenically contaminated estuarine system (Lavaca Bay, TX). THg the solid phase increased with to a maximum located 10−30 cm, which corresponds historic industrial discharges bay. MMHg was highest upper 0−3 cm cores, decreasing rapidly depth. The content surface sediment narrowly constrained fraction (0.65 ± 0.34%) over range types, while making up only 0.01−0.05% Porewater...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMercury speciation in surface freshwater systems California and other areasGary A. Gill Kenneth W. BrulandCite this: Environ. Sci. Technol. 1990, 24, 9, 1392–1400Publication Date (Print):September 1, 1990Publication History Published online1 May 2002Published inissue 1 September 1990https://pubs.acs.org/doi/10.1021/es00079a014https://doi.org/10.1021/es00079a014research-articleACS PublicationsRequest reuse permissionsArticle...
The formation of dissolved gaseous mercury (DGM, mainly composed elemental mercury, Hg0) in the surface ocean and its subsequent removal through volatilization is an important component global (Hg) cycle. We studied DGM production loss coastal waters Gulf Mexico using 4−26 h situ incubation experiments. was only induced presence sunlight. Once produced, rapidly lost from solution (with a first order rate constant k = 0.1 h-1), apparently as result oxidation. Furthermore, labora tory...
Fiber adsorbents synthesized<italic>via</italic>ATRP.
The need to secure future supplies of energy attracts researchers in several countries a vast resource nuclear fuel: uranium seawater (estimated at 4.5 billion tons seawater). In this study, we developed effective adsorbent fibers for the recovery from via atom-transfer radical polymerization (ATRP) poly(vinyl chloride)-co-chlorinated chloride) (PVC-co-CPVC) fiber. ATRP was employed surface graft acrylonitrile (AN) and tert-butyl acrylate (tBA), precursors uranium-interacting functional...
A new series of adsorbents (AI10 through AI17) were successfully developed at ORNL by radiation induced graft polymerization (RIGP) acrylonitrile (AN) and vinylphosphonic acid (VPA) (at different mole to ratios) onto high surface area polyethylene fiber, with degrees grafting (DOG) varying from 110 300%. The grafted nitrile groups converted amidoxime reaction 5 wt % hydroxylamine 80 °C for 72 h. amidoximated then conditioned 0.44 M KOH followed screening prescreening brine spiked 8 ppm...
The Pacific Northwest National Laboratory (PNNL) is evaluating the performance of adsorption materials to extract uranium from natural seawater. Testing consists measurements and other elements seawater as a function time using flow-through columns recirculating flume determine adsorbent capacity kinetics. amidoxime-based polymer AF1, produced by Oak Ridge (ORNL), had 56-day 3.9 ± 0.2 g U/kg material, saturation 5.4 half-saturation 23 2 days. ORNL AF1 has very high affinity for uranium,...
The Marine Science Laboratory at the Pacific Northwest National evaluated impact of biofouling on performance or uranium adsorbents. A surface-modified polyethylene adsorbent fiber provided by Oak Ridge Laboratory, AF adsorbent, was tested in either presence absence light to simulate deployment shallow deep marine environments. Samples were exposed seawater as loose fibers packed with glass beads columns and >10-cm-long braids placed a flume that continuous flow representative natural ocean...
The primary goal of the Florida Atmospheric Mercury Study (FAMS) was to quantify atmospheric deposition Hg throughout Florida. Monthly integrated precipitation and weekly particulate samples were collected at 10 sites in for periods ranging from 2 5 yr. monthly rainfall across state concentrations wet-only bulk increased by a factor 2-3 during summertime "wet season" (May-October). These parallel increases amount concentration resulted 5-8-fold wet season. annual volume-weighted ranged 14...
The aqueous flux of inorganic Hg and monomethyl from sediments to the water column was determined at several sites in Lavaca Bay, an estuary along Texas Coast, historically impacted by discharges. Diffusive fluxes were calculated 15 using interstitial pore gradients compared direct measurements obtained two benthic chambers. diffusive mercury (MMHg), when modeled as a chloride species, varied over 3 orders magnitude 0.2 1500 ng m-2 day-1. single site revealed that MMHg seasonally; maximal...
Surface‐water samples were collected from Galveston Bay, Corpus Christi Sabine Lake, and Laguna Madre analyzed for Hg in the <0.45‐ µ m, 0.45‐ m‐1‐kDa, <1‐kDa fractions. Colloidal material was isolated with an Amicon cross‐flow ultrafiltration system which rigorously tested. Filter‐passing concentrations (< 0.45 m) ranged 0.12 to 13.6 pM, highest values Bay. Within Bays, filter‐passing exhibited nonconservative estuarine mixing behavior. The colloidal fraction 12 93% of pool...
Concentration and phase speciation of Ag in selected Texas rivers the Trinity River estuary were measured order to establish major factors that control its fate aquatic environment from source sink. Concentrations filter-passing fractions ranged <0.01 62 ng/L. In (Galveston Bay), they 0.4 6.4 ng/L showed a non-conservative estuarine mixing behavior. An internal (≤0.45 μm) colloidal (1 kDa−0.45 was observed upper Bay. Silver, associated with macromolecular organic matter, which isolated using...
Five field trips were conducted in the San Francisco Bay‐Delta between May 2000 and October 2001 to investigate sediment‐water exchange of total mercury (Hg) monomethyl (MMHg). Solid‐phase Hg averaged ~1 nmol g −1 did not show any variability with depth or time among sites. In contrast, solid‐phase MMHg showed considerable vertical, temporal, spatial (0.4–66 pmol ), highest values occurring at a peat‐rich environment 2001, suggesting that production was largely controlled by temporal factors...
Total mercury (Hg) concentration was determined in the tissues of 10 pelagic fishes northern Gulf Mexico, and dietary tracers (stable isotopes fatty acids) were used to evaluate relationship between Hg feeding history. Highest levels observed blue marlin (Makaira nigricans), carcharhinid sharks (Carcha rhinus spp.), little tunny (Euthynnus alletteratus), ranging from 1.08 10.52 ppm. Moderate low concentrations (<1.0 ppm) blackfin tuna (Thunnus atlanticus), cobia (Rachycentron canadum),...