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Publications

Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).

Filter Total Items: 3785

Volatilization of ketones Volatilization of ketones

Volatilization fluxes of seven ketones were measured over a range of temperatures. Gas-film coefficients were calculated from these volatilization fluxes and related to the gas-film coefficient for the evaporation of water. These relations, when combined with an equation for estimating the gas-film coefficient for evaporation of water from a canal, permit estimating gas-film coefficients...
Authors
R. E. Rathbun, D. Y. Tai

Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 2. Numerical simulation analysis Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 2. Numerical simulation analysis

The interaction of lakes and groundwater is controlled partly by the geologic framework through which the water flows. Two interrelated geometric factors of the groundwater system that affect flow are overall geometry of the system, and anisotropy of the porous media within the system. Numerical simulation analysis was made for variations in the coefficient of anisotropy for each of...
Authors
T. C. Winter, H.O. Pfannkuch

Denitrification associated with stream periphyton: Chamber estimates from undisrupted communities Denitrification associated with stream periphyton: Chamber estimates from undisrupted communities

Undisrupted periphyton communities from a N‐rich (NO3− = 63 µmol L−1) and pristine (NO3− = 2.9 µmol L−1) stream were assayed for denitrifying activity (acetylene‐blockage technique) in 40‐L chambers incubated at in situ temperature and nutrient concentrations. Nitrous oxide formation associated with periphyton from the N‐rich stream was immediate and linear (52.1 µmol N2O m−2 h−1) in the...
Authors
J.H. Duff, F.J. Triska, R.S. Oremland

Subsurface injection of treated sewage into a saline-water aquifer at St. Petersburg, Florida - Water-quality changes and potential for recovery of injected sewage Subsurface injection of treated sewage into a saline-water aquifer at St. Petersburg, Florida - Water-quality changes and potential for recovery of injected sewage

The city of St. Petersburg is testing subsurface injection of treated sewage into the Floridan aquifer as a means of eliminating discharge of sewage to surface waters and as a means of storing treated sewage for future nonpotable reuse. The injection zone at the test site at the start of injection contained saline water with chloride concentrations ranging from 14,000 to 20,000...
Authors
J.J. Hickey, G. G. Ehrlich

Field testing the hypothesis of Darcian flow through a carbonate aquifer Field testing the hypothesis of Darcian flow through a carbonate aquifer

The acceptability of the hypothesis of Darcian flow through a semiconfined carbonate aquifer was tested prior to running a multiple-day aquifer test in Pinellas County, Florida. The approach used to test the hypothesis was to run a number of hour-long aquifer tests at different discharges with drawdown measured at the same time during each test in two observation wells, one at 35 feet...
Authors
J.J. Hickey

Origin and distribution of carbon dioxide in the unsaturated zone of the southern High Plains of Texas Origin and distribution of carbon dioxide in the unsaturated zone of the southern High Plains of Texas

Partial pressures of CO2, O2, N2, and Ar were monitored at two locations in the Ogallala aquifer system on the Southern High Plains of Texas. Samples were collected monthly during parts of 1980–1981 from nine depths ranging from 0.6 to 36 meters below land surface. PCO2 was observed to be greater at depth than in the active soil zone and thus appears to contradict the normal process in...
Authors
Warren W. Wood, Michael J. Petraitis

Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation

The formation of acid waters by oxidation of pyrite-bearing ore deposits, mine tailing piles, and coal measures is a complex biogeochemical process and is a serious environmental problem. We have studied the oxygen and sulphur isotope geochemistry of sulphides, sulphur, sulphate and water in the field and in experiments to identify sources of oxygen and reaction mechanisms of sulphate...
Authors
B.E. Taylor, M.C. Wheeler, D. Kirk Nordstrom

Bonded-phase extraction column isolation of organic compounds in groundwater at a hazardous waste site Bonded-phase extraction column isolation of organic compounds in groundwater at a hazardous waste site

A procedure for isolation of hazardous organic compounds from water for gas chromatography/mass spectrometry analysis Is presented and applied to creosote- and pentachlorophenol-contaminated groundwater resulting from wood-treatment processes. This simple procedure involved passing a 50-100-mL sample through a bonded-phase extraction column, eluting the trapped organic compounds from the...
Authors
C.E. Rostad, W. E. Pereira, S.M. Ratcliff

Adsorption of goethite onto quartz and kaolinite Adsorption of goethite onto quartz and kaolinite

The adsorption of colloidal goethite onto quartz and kaolinite substrates has been studied as a function of pH and NaCl concentration. Goethite adsorption was measured quantitatively by Fourier-transform infrared spectroscopy. The results indicate that adsorption onto both substrates is due primarily to coulombic forces; however, the pH dependence of adsorption is very different for the...
Authors
M. C. Goldberg, Eugene R. Weiner, P. M. Boymel

Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 1. Analog and dimensional analysis Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 1. Analog and dimensional analysis

Distribution of seepage through lakebeds is controlled partly by geometric configuration of the lake and of the groundwater system interacting with the lake. To evaluate the effect of these factors, conductive-paper electric-analog models were used to analyze a number of lake and groundwater settings having different geometric configurations. Most settings analyzed are of lakes that do...
Authors
H.O. Pfannkuch, T. C. Winter
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