Douglas Kent
Dr. Douglas Kent is a scientist emeritus with the Earth System Processes Division of the Water Mission Area, U. S. Geological Survey.
Doug Kent received an AA from Pasadena City College, 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 focused on processes influencing the mobility of constituents that can affect the availability of water for beneficial use by humans and for sustaining aquatic ecosystems.
Science and Products
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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 of sediments. An additional step was...
Authors
Deborah Stoliker, Kate M. Campbell, Patricia M. Fox, David M. Singer, Nazila Kaviani, Minna Carey, Nicole E. Peck, John R. Barger, Douglas B. Kent, James F. Davis
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, increased with increasing pH (5.5–8.1) and...
Authors
Aria Amirbahman, Douglas B. Kent, Gary Curtis, Mark C. Marvin-DiPasquale
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) adsorption properties of the various size...
Authors
Deborah Stoliker, Chongxuan Liu, Douglas B. Kent, John M. Zachara
Evaluating ion exchange resin efficiency and oxidative capacity for the separation of uranium(IV) and uranium(VI)
No abstract available.
Authors
Deborah Stoliker, Douglas B. Kent, Nazila Kaviani, James F. Davis
Groundwater-quality data for a treated-wastewater plume near the Massachusetts Military Reservation, Ashumet Valley, Cape Cod, Massachusetts, 2006-08
A plume of contaminated groundwater extends from former disposal beds at the Massachusetts Military Reservation's wastewater-treatment plant toward Ashumet Pond, coastal ponds, and Vineyard Sound, Cape Cod, Massachusetts. Treated sewage-derived wastewater was discharged to the rapid-infiltration beds for nearly 60 years before the disposal site was moved to a different location in...
Authors
Jennifer G. Savoie, Denis R. LeBlanc, Gillian M. Fairchild, Richard L. Smith, Douglas B. Kent, Larry B. Barber, Deborah A. Repert, Charles P. Hart, Steffanie H. Keefe, Luke A. Parsons
Mineralogy, morphology, and textural relationships in coatings on quartz grains in sediments in a quartz-sand aquifer
Mineralogical studies of coatings on quartz grains and bulk sediments from an aquifer on Western Cape Cod, Massachusetts, USA were carried out using a variety of transmission electron microscopy (TEM) techniques. Previous studies demonstrated that coatings on quartz grains control the adsorption properties of these sediments. Samples for TEM characterization were made by a gentle...
Authors
Shouliang Zhang, Douglas B. Kent, David C. Elbert, Zhi Shi, James F. Davis, David R. Veblen
Non-USGS Publications**
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.
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.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 53
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 of sediments. An additional step was...
Authors
Deborah Stoliker, Kate M. Campbell, Patricia M. Fox, David M. Singer, Nazila Kaviani, Minna Carey, Nicole E. Peck, John R. Barger, Douglas B. Kent, James F. Davis
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, increased with increasing pH (5.5–8.1) and...
Authors
Aria Amirbahman, Douglas B. Kent, Gary Curtis, Mark C. Marvin-DiPasquale
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) adsorption properties of the various size...
Authors
Deborah Stoliker, Chongxuan Liu, Douglas B. Kent, John M. Zachara
Evaluating ion exchange resin efficiency and oxidative capacity for the separation of uranium(IV) and uranium(VI)
No abstract available.
Authors
Deborah Stoliker, Douglas B. Kent, Nazila Kaviani, James F. Davis
Groundwater-quality data for a treated-wastewater plume near the Massachusetts Military Reservation, Ashumet Valley, Cape Cod, Massachusetts, 2006-08
A plume of contaminated groundwater extends from former disposal beds at the Massachusetts Military Reservation's wastewater-treatment plant toward Ashumet Pond, coastal ponds, and Vineyard Sound, Cape Cod, Massachusetts. Treated sewage-derived wastewater was discharged to the rapid-infiltration beds for nearly 60 years before the disposal site was moved to a different location in...
Authors
Jennifer G. Savoie, Denis R. LeBlanc, Gillian M. Fairchild, Richard L. Smith, Douglas B. Kent, Larry B. Barber, Deborah A. Repert, Charles P. Hart, Steffanie H. Keefe, Luke A. Parsons
Mineralogy, morphology, and textural relationships in coatings on quartz grains in sediments in a quartz-sand aquifer
Mineralogical studies of coatings on quartz grains and bulk sediments from an aquifer on Western Cape Cod, Massachusetts, USA were carried out using a variety of transmission electron microscopy (TEM) techniques. Previous studies demonstrated that coatings on quartz grains control the adsorption properties of these sediments. Samples for TEM characterization were made by a gentle...
Authors
Shouliang Zhang, Douglas B. Kent, David C. Elbert, Zhi Shi, James F. Davis, David R. Veblen
Non-USGS Publications**
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.
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.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.