Peter B McMahon (Former Employee)
Science and Products
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Occurrence of nitrous oxide in the central High Plains aquifer, 1999 Occurrence of nitrous oxide in the central High Plains aquifer, 1999
Nitrogen-enriched groundwater has been proposed as an important anthropogenic source of atmospheric nitrous oxide (N2O), yet few measurements of N2O in large aquifer systems have been made. Concentrations of N2O in water samples collected from the 124 000 km2 central High Plains aquifer in 1999 ranged from 1 to 940 nM, with a median concentration of 29 nM (n = 123). Eighty percent of the...
Authors
P.B. McMahon, B.W. Bruch, M.F. Becker, L. Pope, K.F. Dennehy
Hydraulic and geochemical performance of a permeable reactive barrier containing zero-valent iron, Denver Federal Center Hydraulic and geochemical performance of a permeable reactive barrier containing zero-valent iron, Denver Federal Center
The hydraulic and geochemical performance of a 366 m long permeable reactive barrier (PRB) at the Denver Federal Center, Denver, Colorado, was evaluated. The funnel and gate system, which was installed in 1996 to intercept and remediate ground water contaminated with chlorinated aliphatic hydrocarbons (CAHs), contained four 12.2 m wide gates filled with zero‐valent iron. Ground water...
Authors
P.B. McMahon, K.F. Dennehy, Mark Sandstrom
Denitrification in marine shales in northeastern Colorado Denitrification in marine shales in northeastern Colorado
Parts of the South Platte River alluvial aquifer in northeastern Colorado are underlain by the Pierre Shale, a marine deposit of Late Cretaceous age that is
Authors
Peter McMahon, J.K. Böhlke, Breton Bruce
N2O emissions from a nitrogen-enriched river N2O emissions from a nitrogen-enriched river
Nitrous oxide (N2O) emissions from the South Platte River in Colorado were measured using closed chambers in the fall, winter, and summer of 1994- 1995. The South Platte River was enriched in inorganic N (9-800 ??M) derived from municipal wastewater effluent and groundwater return flows from irrigated agricultural fields. River water was as much as 2500% supersaturated with N2O, and...
Authors
P.B. McMahon, K.F. Dennehy
Shallow ground-water quality of selected land-use/aquifer settings in the South Platte River basin, Colorado and Nebraska, 1993-95 Shallow ground-water quality of selected land-use/aquifer settings in the South Platte River basin, Colorado and Nebraska, 1993-95
No abstract available.
Authors
B. Bruce, P.B. McMahon
Nitrous oxide fluxes from a claypan soil overlying nitrate-enriched glacial drift Nitrous oxide fluxes from a claypan soil overlying nitrate-enriched glacial drift
The closed chamber method was used to assess nitrous oxide (N2O) fluxes from corn (Zea mays, L.) fields during the 1995 growing season. The study area was characterized by a claypan soil overlying a nitrate (NO31-)-enriched glacial-drift aquifer. Denitrification produced N2O fluxes of 0.2-6.9 g ha-1 hr-1 early in the growing season. Fluxes increased with increasing soil temperature, soil...
Authors
M.L. Pomes, D.H. Wilkison, P.B. McMahon
Science and Products
Filter Total Items: 14
No Result Found
Filter Total Items: 118
Occurrence of nitrous oxide in the central High Plains aquifer, 1999 Occurrence of nitrous oxide in the central High Plains aquifer, 1999
Nitrogen-enriched groundwater has been proposed as an important anthropogenic source of atmospheric nitrous oxide (N2O), yet few measurements of N2O in large aquifer systems have been made. Concentrations of N2O in water samples collected from the 124 000 km2 central High Plains aquifer in 1999 ranged from 1 to 940 nM, with a median concentration of 29 nM (n = 123). Eighty percent of the...
Authors
P.B. McMahon, B.W. Bruch, M.F. Becker, L. Pope, K.F. Dennehy
Hydraulic and geochemical performance of a permeable reactive barrier containing zero-valent iron, Denver Federal Center Hydraulic and geochemical performance of a permeable reactive barrier containing zero-valent iron, Denver Federal Center
The hydraulic and geochemical performance of a 366 m long permeable reactive barrier (PRB) at the Denver Federal Center, Denver, Colorado, was evaluated. The funnel and gate system, which was installed in 1996 to intercept and remediate ground water contaminated with chlorinated aliphatic hydrocarbons (CAHs), contained four 12.2 m wide gates filled with zero‐valent iron. Ground water...
Authors
P.B. McMahon, K.F. Dennehy, Mark Sandstrom
Denitrification in marine shales in northeastern Colorado Denitrification in marine shales in northeastern Colorado
Parts of the South Platte River alluvial aquifer in northeastern Colorado are underlain by the Pierre Shale, a marine deposit of Late Cretaceous age that is
Authors
Peter McMahon, J.K. Böhlke, Breton Bruce
N2O emissions from a nitrogen-enriched river N2O emissions from a nitrogen-enriched river
Nitrous oxide (N2O) emissions from the South Platte River in Colorado were measured using closed chambers in the fall, winter, and summer of 1994- 1995. The South Platte River was enriched in inorganic N (9-800 ??M) derived from municipal wastewater effluent and groundwater return flows from irrigated agricultural fields. River water was as much as 2500% supersaturated with N2O, and...
Authors
P.B. McMahon, K.F. Dennehy
Shallow ground-water quality of selected land-use/aquifer settings in the South Platte River basin, Colorado and Nebraska, 1993-95 Shallow ground-water quality of selected land-use/aquifer settings in the South Platte River basin, Colorado and Nebraska, 1993-95
No abstract available.
Authors
B. Bruce, P.B. McMahon
Nitrous oxide fluxes from a claypan soil overlying nitrate-enriched glacial drift Nitrous oxide fluxes from a claypan soil overlying nitrate-enriched glacial drift
The closed chamber method was used to assess nitrous oxide (N2O) fluxes from corn (Zea mays, L.) fields during the 1995 growing season. The study area was characterized by a claypan soil overlying a nitrate (NO31-)-enriched glacial-drift aquifer. Denitrification produced N2O fluxes of 0.2-6.9 g ha-1 hr-1 early in the growing season. Fluxes increased with increasing soil temperature, soil...
Authors
M.L. Pomes, D.H. Wilkison, P.B. McMahon