Kent, D. B., and Kastner, M., 1985, Mg2+ removal in the system Mg2+‑amorphous SiO2‑H2O by adsorption and Mg‑hydroxysilicate precipitation: Geochimica et Cosmochimica Acta, v. 49, p. 1123‑1136.
Douglas Kent
Biography
Doug Kent received a BA in chemistry from the University of California, San Diego and a PhD from Scripps Institution of Oceanography. He has conducted hydrologic research at the USGS since 1985.
Doug Kent's research at the USGS has focussed on processes influencing the mobility of metals and metalloids in groundwater, surface water, and across the groundwater-surface-water interface. Metal and metalloids examined include arsenic, chrominum, copper, lead, nickel, uranium, and zinc.
Science and Products
Date published: June 23, 2021
Status: Completed Geochemical Signatures of Oil and Gas Wastewater from an Accidental Release Detected in Stream Sediment and Pore Waters Two Years Post Spill
Scientists identified geochemical signatures of wastewater in Blacktail Creek, North Dakota, as a result of a 2015 pipeline leak. They demonstrated that environmental signatures from wastewater spills are persistent within a short (1-3 year) time frame, can enter the creek through subsurface pathways, and can create the potential for extended environmental exposures.
Contacts: Isabelle M Cozzarelli, Ph.D., Douglas Kent
Year Published: 2021
Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
Releases of oil and gas (OG) wastewaters can have complex effects on stream-water quality and downstream organisms, due to sediment-water interactions and groundwater/surface water exchange. Previously, elevated concentrations of sodium (Na), chloride (Cl), barium (Ba), strontium (Sr), and lithium (Li), and trace hydrocarbons were determined to be...
Cozzarelli, Isabelle M.; Kent, Douglas B.; Briggs, Martin A.; Engle, Mark A; Benthem, Adam; Skalak, Katherine; Mumford, Adam; Jaeschke, Jeanne B.; Farag, Aida; Lane, Jr., John W.; Akob, Denise M.
Year Published: 2019
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
Groundwater discharge delivering anthropogenic N from surrounding watersheds can impact lake nutrient budgets. However, upgradient groundwater processes and changing dynamics in N biogeochemistry at the groundwater-lake interface are complex and difficult to resolve. In this study, hydrograph variations in a groundwater flow-through lake...
Smith, Richard L.; Repert, Deborah A.; Stoliker, Deborah; Kent, Douglas B.; Song, Bongkeun; LeBlanc, Denis R.; McCobb, Timothy; Böhlke, John K.; Hyun, Sung Pil; Moon, Hee Sun
Year Published: 2018
When oil and water mix: Understanding the environmental impacts of shale development
Development of shale gas and tight oil, or unconventional oil and gas (UOG), has dramatically increased domestic energy production in the U.S. UOG resources are typically developed through the use of hydraulic fracturing, which creates high-permeability flow paths into large volumes of tight rocks to provide a means for hydrocarbons to move to a...
Soeder, Daniel J.; Kent, Douglas B.Attribution: Water Resources,
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Soeder, D.J., and Kent, D.B., 2018, When oil and water mix: Understanding the environtmental impacts of shale development: GSA Today, v. 28, https://doi.org/10.1130/GSATG361A.1.
Year Published: 2017
Extent and persistence of secondary water quality impacts after enhanced reductive bioremediation
Electron donor (ED) addition can be very effective in stimulating enhanced reductive bioremediation (ERB) of a wide variety of groundwater contaminants. However, ERB can result in Secondary Water Quality Impacts (SWQIs) including decreased levels of dissolved oxygen (O2), nitrate (NO3- ), and sulfate (SO42- ), and elevated levels of dissolved...
Borden, Robert C.; Jason M. Tillotson; Ng, Gene-Hua Crystal.; Bekins, Barbara A.; Kent, Douglas B.; Curtis, Gary P.Attribution: Water Resources,
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Borden, R.C., Tillotson, J.M., Ng, G.C., Bekins, B.A., Kent, D.B., Curtis, G.P., 2015, Extent and Persistence of Secondary Water Quality Impacts after Enhanced Reductive Bioremediation, SERDP Project ER-2131
Year Published: 2017
Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota
Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4 M L (million liters) of wastewater (300 g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples...
Cozzarelli, Isabelle M.; Skalak, Katherine; Kent, D.B.; Engle, Mark A.; Benthem, Adam J.; Mumford, Adam; Haase, Karl B.; Farag, Aïda M.; Harper, David; Nagel, S. C.; Iwanowicz, Luke R.; Orem, William H.; Akob, Denise M.; Jaeschke, Jeanne B.; Galloway, Joel M.; Kohler, Matthias; Stoliker, Deborah L.; Jolly, Glenn D.
Year Published: 2017
Anoxic nitrate reduction coupled with iron oxidation and attenuation of dissolved arsenic and phosphate in a sand and gravel aquifer
Nitrate has become an increasingly abundant potential electron acceptor for Fe(II) oxidation in groundwater, but this redox couple has not been well characterized within aquifer settings. To investigate this reaction and some of its implications for redox-sensitive groundwater contaminants, we conducted an in situ field study in a wastewater-...
Smith, Richard L.; Kent, Douglas B.; Repert, Deborah A.; Böhlke, J.K.
Year Published: 2016
Wastewater disposal from unconventional oil and gas development degrades stream quality at a West Virginia injection facility
The development of unconventional oil and gas (UOG) resources has rapidly increased in recent years; however, the environmental impacts and risks are poorly understood. A single well can generate millions of liters of wastewater, representing a mixture of formation brine and injected hydraulic fracturing fluids. One of the most common methods for...
Akob, Denise M.; Mumford, Adam; Orem, William H.; Engle, Mark A.; Klinges, Julia (Grace); Kent, Douglas B.; Cozzarelli, Isabelle M.Attribution: , Water Resources, Ecosystems, Energy & Wildlife, Toxic Substances Hydrology, Environmental Health Program, United States of America, Reston Biogeochemical Processes in Groundwater Laboratory, Reston Microbiology Laboratory
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Akob, D.M., A. Mumford, W. H. Orem, M. Engle, J.G. Klinges, D. B. Kent and I. M. Cozzarelli. Wastewater Disposal from Unconventional Oil and Gas Development Degrades Stream Quality at a West Virginia Injection Facility. Environmental Science and Technology, 50 (11): 5517–5525
Year Published: 2016
Hydrologic controls on nitrogen cycling processes and functional gene abundance in sediments of a groundwater flow-through lake
The fate and transport of inorganic nitrogen (N) is a critically important issue for human and aquatic ecosystem health because discharging N-contaminated groundwater can foul drinking water and cause algal blooms. Factors controlling N-processing were examined in sediments at three sites with contrasting hydrologic regimes at a lake on Cape Cod,...
Stoliker, Deborah L.; Repert, Deborah A.; Smith, Richard L.; Song, Bongkeun; LeBlanc, Denis R.; McCobb, Timothy D.; Conaway, Christopher; Hyun, Sung Pil; Koh, Dong-Chan; Moon, Hee Sun; Kent, Douglas B.
Year Published: 2013
Mercury speciation and mobilization in a wastewater-contaminated groundwater plume
We measured the concentration and speciation of mercury (Hg) in groundwater down-gradient from the site of wastewater infiltration beds operated by the Massachusetts Military Reservation, western Cape Cod, Massachusetts. Total mercury concentrations in oxic, mildly acidic, uncontaminated groundwater are 0.5–1 pM, and aquifer sediments have 0.5–1...
Lamborg, Carl H.; Kent, Doug B.; Swarr, Gretchen J.; Munson, Kathleen M.; Kading, Tristan; O'Connor, Alison E.; Fairchild, Gillian M.; LeBlanc, Denis R.; Wiatrowski, Heather A.Attribution: Water Resources,
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Mercury speciation and mobilization in a wastewater-contaminated groundwater plume; 2013; Article; Journal; Environmental Science & Technology; Lamborg, Carl H.; Kent, Doug B.; Swarr, Gretchen J.; Munson, Kathleen M.; Kading, Tristan; O'Connor, Alison E.; Fairchild, Gillian M.; LeBlanc, Denis R.; Wiatrowski, Heather A.
Year Published: 2013
Evaluating chemical extraction techniques for the determination of uranium oxidation state in reduced aquifer sediments
Extraction techniques utilizing high pH and (bi)carbonate concentrations were evaluated for their efficacy in determining the oxidation state of uranium (U) in reduced sediments collected from Rifle, CO. Differences in dissolved concentrations between oxic and anoxic extractions have been proposed as a means to quantify the U(VI) and U(IV) content...
Stoliker, Deborah L.; Campbell, Kate M.; Fox, Patricia M.; Singer, David M.; Kaviani, Nazila; Carey, Minna; Peck, Nicole E.; Barger, John R.; Kent, Douglas B.; Davis, James A.Attribution: Water Resources,
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Evaluating chemical extraction techniques for the determination of uranium oxidation state in reduced aquifer sediments; 2013; Article; Journal; Environmental Science & Technology; Stoliker, Deborah L.; Campbell, Kate M.; Fox, Patricia M.; Singer, David M.; Kaviani, Nazila; Carey, Minna; Peck, Nicole E.; Barger, John R.; Kent, Douglas B.; Davis, James A.
Year Published: 2013
Kinetics of homogeneous and surface-catalyzed mercury(II) reduction by iron(II)
Production of elemental mercury, Hg(0), via Hg(II) reduction is an important pathway that should be considered when studying Hg fate in environment. We conducted a kinetic study of abiotic homogeneous and surface-catalyzed Hg(0) production by Fe(II) under dark anoxic conditions. Hg(0) production rate, from initial 50 pM Hg(II) concentration,...
Amirbahman, Aria; Kent, Douglas B.; Curtis, Gary P.; Marvin-DiPasquale, Mark C.Attribution: Water Resources,
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Kinetics of homogeneous and surface-catalyzed mercury(II) reduction by iron(II); 2013; Article; Journal; Environmental Science & Technology; Amirbahman, Aria ; Kent, Douglas B.; Curtis, Gary P.; Marvin-DiPasquale, Mark C.
Year Published: 2013
Characterizing particle-scale equilibrium adsorption and kinetics of uranium(VI) desorption from U-contaminated sediments
Rates of U(VI) release from individual dry-sieved size fractions of a field-aggregated, field-contaminated composite sediment from the seasonally saturated lower vadose zone of the Hanford 300-Area were examined in flow-through reactors to maintain quasi-constant chemical conditions. The principal source of variability in equilibrium U(VI)...
Stoliker, Deborah L.; Liu, Chongxuan; Kent, Douglas B.; Zachara, John M.Attribution: Water Resources
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Characterizing particle-scale equilibrium adsorption and kinetics of uranium(VI) desorption from U-contaminated sediments; 2013; Article; Journal; Water Resources Research; Stoliker, Deborah L.; Liu, Chongxuan ; Kent, Douglas B.; Zachara, John M.
Pre-USGS Publications
On the surface chemical properties of synthetic and biogenic amorphous silica
Kent, D. B., 1983, On the surface chemical properties of synthetic and biogenic amorphous silica: Ph.D. dissertation, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, 420 pp.