A5019404893- Groundwater and Isotope Geochemistry
- Groundwater flow and contamination studies
- Radioactive contamination and transfer
- Isotope Analysis in Ecology
- Hydrology and Watershed Management Studies
- Water Quality and Resources Studies
- Geochemistry and Elemental Analysis
- Soil and Water Nutrient Dynamics
- Atmospheric and Environmental Gas Dynamics
- Heavy metals in environment
- Nuclear and radioactivity studies
- Geochemistry and Geologic Mapping
- Marine and coastal ecosystems
- Radioactivity and Radon Measurements
- Mercury impact and mitigation studies
- Radioactive element chemistry and processing
- Water Treatment and Disinfection
- Geology and Paleoclimatology Research
- Mine drainage and remediation techniques
- Reservoir Engineering and Simulation Methods
- Geological and Geochemical Analysis
- Wastewater Treatment and Nitrogen Removal
- Analytical chemistry methods development
- Methane Hydrates and Related Phenomena
- Hydrocarbon exploration and reservoir analysis
Louisiana State University
2021
Xiamen University
2021
Osaka University
2021
University of Freiburg
2021
Silesian University of Technology
2021
Centre of Polymer and Carbon Materials
2021
Shangqiu Normal University
2021
Yangzhou University
2021
Ca' Foscari University of Venice
2021
Lawrence Livermore National Laboratory
2011-2020
Osmium isotopic compositions and concentrations have been determined for deltaic continental shelf sediments from three major rivers (the Amazon, Changjiang, Mississippi) two loesses the upper Mississippi River Valley. The heavy mineral clay characteristic of river delta sediment. Concentrations range 15 to 120 pg Os/g, 187Os/186Os ratios 8.2 10.9. Sediments which are polluted (surface sediment Changjiang Estuary) or scavenged metals seawater (Gulf Mexico slope surface distal Amazon Shelf...
Hexavalent chromium, Cr(VI), in 918 wells sampled throughout California between 2004 and 2012 by the Groundwater Ambient Monitoring Assessment-Priority Basin Project (GAMA-PBP) ranged from less than study reporting limit of 1 microgram per liter (μg/L) to 32 μg/L. Statewide, Cr(VI) was reported 31 percent equaled or exceeded recently established (2014) Maximum Contaminant Level (MCL) for 10 μg/L 4 wells. data collected regulatory purposes overestimated occurrence compared...
Abstract One of the principal questions in hydrology is how and when water leaves critical zone storage as either stream flow or evapotranspiration. We investigated subsurface selection Southern Sierra Critical Zone Observatory (California, USA) within age‐ranked framework, constrained by a novel combination cosmogenic radioactive stable isotopes: tritium, sodium‐22, sulfur‐35, oxygen‐18. found significant positive correlation between tritium rate sulfur‐35 rate, indicating that age...
We present results from field studies at two central California dairies that demonstrate the prevalence of saturated-zone denitrification in shallow groundwater with 3H/ 3He apparent ages < 35 years. Concentrated animal feeding operations are suspected to be major contributors nitrate groundwater, but saturated zone could mitigate their impact quality. Denitrification is identified and quantified using N O stable isotope compositions coupled measurements excess N2 residual NO3(-)...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreconcentration and Purification of Rare Earth Elements in Natural Waters Using Silica-Immobilized 8-Hydroxyquinoline a Supported Organophosphorus ExtractantBradley K. Esser, Alan. Volpe, Jacqueline M. Kenneally, David SmithCite this: Anal. Chem. 1994, 66, 10, 1736–1742Publication Date (Print):May 15, 1994Publication History Published online1 May 2002Published inissue 15...
ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTEnvironmental AnalysisCarolyn J. Koester, Staci L. Simonich, and Bradley K. EsserView Author Information Analytical Nuclear Chemistry Division, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 Department of Environmental Molecular Toxicology Chemistry, Oregon State University, Corvallis, 97331-7301 Cite this: Anal. Chem. 2003, 75, 12, 2813–2829Publication Date (Web):May 3, 2003Publication History Published...
Identifying and reducing impacts from mercury sources in the environment remains a considerable challenge requires process based models to quantify stocks flows. The stable isotope composition of environmental samples can help address this by serving as tracer specific processes. Mercury variations are small result only fractionation during transport, equilibrium, transformation Because these processes occur both industrial settings, knowledge their associated effects is required interpret...
Gas exchange across the air-water interface is a critical process that maintains adequate dissolved oxygen (DO) in water column to support life. Oxygen reaeration rates can be accurately measured using deliberate gas tracers, like sulfur hexafluoride (SF6) or xenon (Xe). Two continuous release experiments were conducted different creeks Sierra Nevada of California: Sagehen Creek September, 2009, SF6 and Martis August, 2012, both Xe. Measuring loss along creek, which was approximated with...
Abstract Groundwater is not a sustainable resource, unless abstraction balanced by recharge. Identifying the sources of recharge in groundwater basin critical for management. We studied importance river water to south‐eastern San Joaquin Valley (24,000 km 2 , population 4 million). combined dissolved noble gas concentrations, stable isotopes, tritium, and carbon‐14 analyses analyse sources, mechanisms, timescales Area‐representative sampling numerical model input data enabled isotope mass...
A new method is described for measuring dissolved gas concentrations in small volumes of xylem sap using membrane inlet mass spectrometry. The technique can be used to determine atmospheric gases, such as argon, reported here, or any gases and their isotopes a variety applications, rapid detection trace from groundwater only hours after they were taken up by trees rooting depth estimation. Atmospheric content directly affects the conditions mechanisms that allow removal embolisms, because...
The 187Os186Os ratios of acidic hydrogen peroxide leaches river sediments are inferred to be representative the isotopic composition Os delivered sea water from continents. values for sediment eastern and central U.S., Ganges River, Rio Maipo range 10.1 21.5. These results suggest that soluble load major continental areas oceans is, on average, more radiogenic than average currently eroding crust (10.5). Sediment three rivers western U.S. drain ophiolitic peridotites have distinctly lower...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnthropogenic osmium in coastal depositsBradley K. Esser and Karl TurekianCite this: Environ. Sci. Technol. 1993, 27, 13, 2719–2724Publication Date (Print):December 1, 1993Publication History Published online1 May 2002Published inissue 1 December 1993https://pubs.acs.org/doi/10.1021/es00049a010https://doi.org/10.1021/es00049a010research-articleACS PublicationsRequest reuse permissionsArticle Views122Altmetric-Citations47LEARN ABOUT THESE...
During the dry months of water year in Mediterranean climates, groundwater influx is essential to perennial streams for sustaining ecosystem health and regulating temperature. Predicted earlier peak flow due climate change may result decreased baseflow transformation intermittent streams. In this study, naturally occurring radon-222 (222Rn) was used as a tracer Martis Creek, subalpine stream near Lake Tahoe, CA. Groundwater 222Rn estimated based on measurements activity nearby deep wells...