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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Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source
Disposal of treated wastewater for more than 60 years onto infiltration beds on Cape Cod, Massachusetts produced a groundwater contaminant plume greater than 6 km long in a surficial sand and gravel aquifer. In December 1995 the wastewater disposal ceased. A long-term, continuous study was conducted to characterize the post-cessation attenuation of the plume from the source to 0.6 km...
Authors
D.A. Repert, L. B. Barber, K.M. Hess, S.H. Keefe, D.B. Kent, D.R. LeBlanc, R. L. Smith
Tracer test with As(V) under variable redox conditions controlling arsenic transport in the presence of elevated ferrous iron concentrations Tracer test with As(V) under variable redox conditions controlling arsenic transport in the presence of elevated ferrous iron concentrations
To study transport and reactions of arsenic under field conditions, a small-scale tracer test was performed in an anoxic, iron-reducing zone of a sandy aquifer at the USGS research site on Cape Cod, Massachusetts, USA. For four weeks, a stream of groundwater with added As(V) (6.7 μM) and bromide (1.6 mM), was injected in order to observe the reduction of As(V) to As(III). Breakthrough of...
Authors
R. Hohn, M. Isenbeck-Schroter, D.B. Kent, J.A. Davis, R. Jakobsen, S. Jann, V. Niedan, C. Scholz, S. Stadler, A. Tretner
Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials
The fate of arsenic in groundwater depends largely on its interaction with mineral surfaces. We investigated the kinetics of As(III) oxidation by aquifer materials collected from the USGS research site at Cape Cod, MA, USA, by conducting laboratory experiments. Five different solid samples with similar specific surface areas (0.6–0.9 m2 g−1) and reductively extractable iron contents (18...
Authors
A. Amirbahman, D.B. Kent, G.P. Curtis, J.A. Davis
Changes in ground-water quality near two granular-iron permeable reactive barriers in a sand and gravel aquifer, Cape Cod, Massachusetts, 1997-2000 Changes in ground-water quality near two granular-iron permeable reactive barriers in a sand and gravel aquifer, Cape Cod, Massachusetts, 1997-2000
Two experimental permeable reactive barriers (PRBs) of granular zero-valent iron were emplaced in the path of a tetrachloroethene plume (the Chemical Spill-10 plume) at the Massachusetts Military Reservation, Cape Cod, Massachusetts, in June 1998. The goal of the field experiment was to achieve emplacement of a granular-iron PRB deeper than attempted before. The PRBs were expected to...
Authors
Jennifer G. Savoie, Douglas B. Kent, Richard L. Smith, Denis R. LeBlanc, David W. Hubble
The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer
We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As) in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: (1) the uncontaminated zone above the sewage plume [350 μM dissolved oxygen (DO), pH 5.9];...
Authors
D.B. Kent, P.M. Fox
Phosphorus in a ground-water contaminant plume discharging to Ashumet Pond, Cape Cod, Massachusetts, 1999 Phosphorus in a ground-water contaminant plume discharging to Ashumet Pond, Cape Cod, Massachusetts, 1999
The discharge of a plume of sewagecontaminated ground water emanating from the Massachusetts Military Reservation to Ashumet Pond on Cape Cod, Massachusetts, has caused concern about excessive loading of nutrients, particularly phosphorus, to the pond. The U.S. Air Force is considering remedial actions to mitigate potentially adverse effects on the ecological characteristics of the pond...
Authors
Timothy D. McCobb, Denis R. LeBlanc, Donald A. Walter, Kathryn M. Hess, Douglas B. Kent, Richard L. Smith
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
Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source
Disposal of treated wastewater for more than 60 years onto infiltration beds on Cape Cod, Massachusetts produced a groundwater contaminant plume greater than 6 km long in a surficial sand and gravel aquifer. In December 1995 the wastewater disposal ceased. A long-term, continuous study was conducted to characterize the post-cessation attenuation of the plume from the source to 0.6 km...
Authors
D.A. Repert, L. B. Barber, K.M. Hess, S.H. Keefe, D.B. Kent, D.R. LeBlanc, R. L. Smith
Tracer test with As(V) under variable redox conditions controlling arsenic transport in the presence of elevated ferrous iron concentrations Tracer test with As(V) under variable redox conditions controlling arsenic transport in the presence of elevated ferrous iron concentrations
To study transport and reactions of arsenic under field conditions, a small-scale tracer test was performed in an anoxic, iron-reducing zone of a sandy aquifer at the USGS research site on Cape Cod, Massachusetts, USA. For four weeks, a stream of groundwater with added As(V) (6.7 μM) and bromide (1.6 mM), was injected in order to observe the reduction of As(V) to As(III). Breakthrough of...
Authors
R. Hohn, M. Isenbeck-Schroter, D.B. Kent, J.A. Davis, R. Jakobsen, S. Jann, V. Niedan, C. Scholz, S. Stadler, A. Tretner
Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials
The fate of arsenic in groundwater depends largely on its interaction with mineral surfaces. We investigated the kinetics of As(III) oxidation by aquifer materials collected from the USGS research site at Cape Cod, MA, USA, by conducting laboratory experiments. Five different solid samples with similar specific surface areas (0.6–0.9 m2 g−1) and reductively extractable iron contents (18...
Authors
A. Amirbahman, D.B. Kent, G.P. Curtis, J.A. Davis
Changes in ground-water quality near two granular-iron permeable reactive barriers in a sand and gravel aquifer, Cape Cod, Massachusetts, 1997-2000 Changes in ground-water quality near two granular-iron permeable reactive barriers in a sand and gravel aquifer, Cape Cod, Massachusetts, 1997-2000
Two experimental permeable reactive barriers (PRBs) of granular zero-valent iron were emplaced in the path of a tetrachloroethene plume (the Chemical Spill-10 plume) at the Massachusetts Military Reservation, Cape Cod, Massachusetts, in June 1998. The goal of the field experiment was to achieve emplacement of a granular-iron PRB deeper than attempted before. The PRBs were expected to...
Authors
Jennifer G. Savoie, Douglas B. Kent, Richard L. Smith, Denis R. LeBlanc, David W. Hubble
The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer
We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As) in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: (1) the uncontaminated zone above the sewage plume [350 μM dissolved oxygen (DO), pH 5.9];...
Authors
D.B. Kent, P.M. Fox
Phosphorus in a ground-water contaminant plume discharging to Ashumet Pond, Cape Cod, Massachusetts, 1999 Phosphorus in a ground-water contaminant plume discharging to Ashumet Pond, Cape Cod, Massachusetts, 1999
The discharge of a plume of sewagecontaminated ground water emanating from the Massachusetts Military Reservation to Ashumet Pond on Cape Cod, Massachusetts, has caused concern about excessive loading of nutrients, particularly phosphorus, to the pond. The U.S. Air Force is considering remedial actions to mitigate potentially adverse effects on the ecological characteristics of the pond...
Authors
Timothy D. McCobb, Denis R. LeBlanc, Donald A. Walter, Kathryn M. Hess, Douglas B. Kent, Richard L. Smith
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.