Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Importance of methane-oxidizing bacteria in the methane budget as revealed by the use of a specific inhibitor
METHANE is a greenhouse gas whose concentration in the atmosphere is increasing. Much of this methane is derived from the metabolism of methane-generating (methanogenic) bacteria and over the past two decades much has been learned about the ecology of methanogens; specific inhibitors of methanogenesis, such as 2-bromoethanesulphonic acid, have proved useful in this regard. In contrast, although mu
Authors
Ronald S. Oremland, Charles W. Culbertson
Floodplain storage of mine tailings in the Belle Fourche river system: a sediment budget approach
Arsenic‐contaminated mine tailings that were discharged into Whitewood Creek at Lead, South Dakota, from 1876 to 1978, were deposited along the floodplains of Whitewood Creek and the Belle Fourche River. The resulting arsenic‐contaminated floodplain deposit consists mostly of overbank sediments and filled abandoned meanders along White‐wood Creek, and overbank and point‐bar sediments along the Bel
Authors
D. C. Marron
Methanogenic degradation kinetics of phenolic compounds in aquifer-derived microcosms
In this segment of a larger multidisciplinary study of the movement and fate of creosote derived compounds in a sand-and-gravel aquifer, we present evidence that the methanogenic degradation of the major biodegradable phenolic compounds and concomitant microbial growth in batch microcosms derived from contaminated aquifer material can be described using Monod kinetics. Substrate depletion and bact
Authors
E.M. Godsy, D.F. Goerlitz, D. Grbic-Galic
Isolation of hydrophilic organic acids from water using nonionic macroporous resins
A method has been developed for the isolation of hydrophilic organic acids from aquatic environments using Amberlite∗ XAD-4 resin. The method uses a two column array of XAD-8 and XAD-4 resins in series. The hydrophobic organic acids, composed primarily of aquatic fulvic acid, are removed from the sample on XAD-8, followed by the isolation of the more hydrophilic organic acids on XAD-4. For samples
Authors
G. R. Aiken, Diane M. McKnight, K. A. Thorn, E.M. Thurman
Herbicide transport in rivers: Importance of hydrology and geochemistry in nonpoint-source contamination
Alachlor, atrazine, cyanazine, metolachlor, and metribuzin were measured at six sites during 1984 and 1985 in large subbasins within the Cedar River, IA. A computer model separated the Cedar River discharge hydrograph into groundwater and overland-flow components. The concentration of herbicides in the river when groundwater was the major flow component was less than 1.0 μg/L and averaged 0.2 μg/L
Authors
P. J. Squillace, E.M. Thurman
Mixed-mode isolation of triazine metabolites from soil and aquifer sediments using automated solid-phase extraction
No abstract available.
Authors
M. S. Mills, E.M. Thurman
Ground-penetrating radar: A tool for mapping reservoirs and lakes
Ground-penetrating radar was evaluated as a tool for mapping reservoir and lake bottoms and providing stage-storage information. An impulse radar was used on a 1.4-ha (3.5-acre) reservoir with 31 transects located 6.1 m (20 feet) apart. Depth of water and lateral extent of the lake bottom were accurately measured by ground-penetrating radar. A linear (positive) relationship existed between measure
Authors
C.C. Truman, L.E. Asmussen, H.D. Allison
Geochemistry of dissolved inorganic carbon in a Coastal Plain aquifer. 2. Modeling carbon sources, sinks, and δ13C evolution
Stable isotope data for dissolved inorganic carbon (DIC), carbonate shell material and cements, and microbial CO2 were combined with organic and inorganic chemical data from aquifer and confining-bed pore waters to construct geochemical reaction models along a flowpath in the Black Creek aquifer of South Carolina. Carbon-isotope fractionation between DIC and precipitating cements was treated as a
Authors
Peter B. McMahon, Francis H. Chapelle
Evaluation of hydraulic conductivities calculated from multi-port permeameter measurements
A multiport permeameter was developed for use in estimating hydraulic conductivity over intact sections of aquifer core using the core liner as the permeameter body. Six cores obtained from one borehole through the upper 9 m of a stratified glacial-outwash aquifer were used to evaluate the reliability of the permeameter. Radiographs of the cores were used to assess core integrity and to locate 5-
Authors
Steven H. Wolf, Michael A. Celia, Kathryn M. Hess
Quartz dissolution in organic-rich aqueous systems
Organic electrolytes are a common component of natural waters and are known to be important in many rock-water interactions. The influence of organic electrolytes on silica mobility, quartz solubility, and quartz dissolution kinetics, however, is less well understood. While there is mounting evidence supporting the presence of an aqueous organic-silica complex in natural waters, the significance o
Authors
Philip C. Bennett
Agricultural research to improve water quality
ime courses for ingest~on, retention and release via feces of microbial food was investigatedusing 2 b~valves w~th d~fferent feeding strategies, Potamocorbula amurensis and Macomabalthica. The results showed 2 pathways for the uptake of food material in these clams. The first isrepresented by an initlal label pulse in the feces. The second pathway operates over longer timeperiods. Inert "Cr-labele
Authors
C.A. Onstad, M. R. Burkart, G.D. Bubenzer
Centrifugal techniques for measuring saturated hydraulic conductivity
Centrifugal force is an alternative to large pressure gradients for the measurement of low values of saturated hydraulic conductivity (Ksat). With a head of water above a porous medium in a centrifuge bucket, both constant-head and falling-head measurements are practical at forces up to at least 1800 times normal gravity. Darcy's law applied to the known centrifugal potential leads to simple formu
Authors
John R. Nimmo, Karen A. Mello