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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Quantifying differences in the impact of variable chemistry on equilibrium uranium(VI) adsorption properties of aquifer sediments Quantifying differences in the impact of variable chemistry on equilibrium uranium(VI) adsorption properties of aquifer sediments
Uranium adsorption-desorption on sediment samples collected from the Hanford 300-Area, Richland, WA varied extensively over a range of field-relevant chemical conditions, complicating assessment of possible differences in equilibrium adsorption properties. Adsorption equilibrium was achieved in 500-1000 h although dissolved uranium concentrations increased over thousands of hours owing...
Authors
Deborah L. Stoliker, Douglas B. Kent, John M. Zachara
Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments
In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity...
Authors
Jun Yin, Roy Haggerty, Deborah L. Stoliker, Douglas B. Kent, Jonathan D. Istok, Janek Greskowiak, John M. Zachara
Redox transformations and transport of cesium and iodine (-1, 0, +5) in oxidizing and reducing zones of a sand and gravel aquifer Redox transformations and transport of cesium and iodine (-1, 0, +5) in oxidizing and reducing zones of a sand and gravel aquifer
Tracer tests were performed in distinct biogeochemical zones of a sand and gravel aquifer in Cape Cod, MA, to study the redox chemistry (I) and transport (Cs, I) of cesium and iodine in a field setting. Injection of iodide (I -) into an oxic zone of the aquifer resulted in oxidation of I - to molecular iodine (I2) and iodate (IO3-) over transport distances of several meters. Oxidation is
Authors
Patricia M. Fox, Douglas B. Kent, James A. Davis
Influence of variable chemical conditions on EDTA-enhanced transport of metal ions in mildly acidic groundwater Influence of variable chemical conditions on EDTA-enhanced transport of metal ions in mildly acidic groundwater
Adsorption of Ni and Pb on aquifer sediments from Cape Cod, Massachusetts, USA increased with increasing pH and metal-ion concentration. Adsorption could be described quantitatively using a semi-mechanistic surface complexation model (SCM), in which adsorption is described using chemical reactions between metal ions and adsorption sites. Equilibrium reactive transport simulations...
Authors
D.B. Kent, J.A. Davis, J.L. Joye, G.P. Curtis
Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer
[1] Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of 4.5 resulting from equilibration with carbon dioxide gas, and added potassium bromide (KBr). Downgradient...
Authors
Douglas B. Kent, J.A. Wilkie, J.A. Davis
Ground-water-quality data for a treated-wastewater plume undergoing natural restoration, Ashumet Valley, Cape Cod, Massachusetts Ground-water-quality data for a treated-wastewater plume undergoing natural restoration, Ashumet Valley, Cape Cod, Massachusetts
A plume of contaminated ground water extends from former disposal beds at the Massachusetts Military Reservation wastewater-treatment plant toward Ashumet Pond, and farther southward toward 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...
Authors
Jennifer G. Savoie, Richard L. Smith, Douglas B. Kent, Kathryn M. Hess, Denis R. LeBlanc, Larry B. Barber
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: 15
No Result Found
Filter Total Items: 53
Quantifying differences in the impact of variable chemistry on equilibrium uranium(VI) adsorption properties of aquifer sediments Quantifying differences in the impact of variable chemistry on equilibrium uranium(VI) adsorption properties of aquifer sediments
Uranium adsorption-desorption on sediment samples collected from the Hanford 300-Area, Richland, WA varied extensively over a range of field-relevant chemical conditions, complicating assessment of possible differences in equilibrium adsorption properties. Adsorption equilibrium was achieved in 500-1000 h although dissolved uranium concentrations increased over thousands of hours owing...
Authors
Deborah L. Stoliker, Douglas B. Kent, John M. Zachara
Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments
In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity...
Authors
Jun Yin, Roy Haggerty, Deborah L. Stoliker, Douglas B. Kent, Jonathan D. Istok, Janek Greskowiak, John M. Zachara
Redox transformations and transport of cesium and iodine (-1, 0, +5) in oxidizing and reducing zones of a sand and gravel aquifer Redox transformations and transport of cesium and iodine (-1, 0, +5) in oxidizing and reducing zones of a sand and gravel aquifer
Tracer tests were performed in distinct biogeochemical zones of a sand and gravel aquifer in Cape Cod, MA, to study the redox chemistry (I) and transport (Cs, I) of cesium and iodine in a field setting. Injection of iodide (I -) into an oxic zone of the aquifer resulted in oxidation of I - to molecular iodine (I2) and iodate (IO3-) over transport distances of several meters. Oxidation is
Authors
Patricia M. Fox, Douglas B. Kent, James A. Davis
Influence of variable chemical conditions on EDTA-enhanced transport of metal ions in mildly acidic groundwater Influence of variable chemical conditions on EDTA-enhanced transport of metal ions in mildly acidic groundwater
Adsorption of Ni and Pb on aquifer sediments from Cape Cod, Massachusetts, USA increased with increasing pH and metal-ion concentration. Adsorption could be described quantitatively using a semi-mechanistic surface complexation model (SCM), in which adsorption is described using chemical reactions between metal ions and adsorption sites. Equilibrium reactive transport simulations...
Authors
D.B. Kent, J.A. Davis, J.L. Joye, G.P. Curtis
Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer
[1] Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of 4.5 resulting from equilibration with carbon dioxide gas, and added potassium bromide (KBr). Downgradient...
Authors
Douglas B. Kent, J.A. Wilkie, J.A. Davis
Ground-water-quality data for a treated-wastewater plume undergoing natural restoration, Ashumet Valley, Cape Cod, Massachusetts Ground-water-quality data for a treated-wastewater plume undergoing natural restoration, Ashumet Valley, Cape Cod, Massachusetts
A plume of contaminated ground water extends from former disposal beds at the Massachusetts Military Reservation wastewater-treatment plant toward Ashumet Pond, and farther southward toward 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...
Authors
Jennifer G. Savoie, Richard L. Smith, Douglas B. Kent, Kathryn M. Hess, Denis R. LeBlanc, Larry B. Barber
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.