Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Humic substances as a mediator for microbially catalyzed metal reduction
The potential for humic substances to serve as a terminal electron acceptor in microbial respiration and to function as an electron shuttle between Fe(III)‐reducing microorganisms and insoluble Fe(III) oxides was investigated. The Fe(III)‐reducing microorganism Geobacter metallireducens conserved energy to support growth from electron transport to humics as evidenced by continued oxidation of acet
Authors
D. R. Lovley, J.L. Fraga, E. L. Blunt-Harris, L.A. Hayes, E. J. P. Phillips, J.D. Coates
AIRSLUG: A fortran program for the computation of type curves to estimate transmissivity and storativity from prematurely terminated air-pressurized slug tests
The Fortran code AIRSLUG can be used to generate the type curves needed to analyze the recovery data from prematurely terminated air-pressurized slug tests. These type curves, when used with a graphical software package, enable the engineer or scientist to analyze field tests to estimate transmissivity and storativity. Prematurely terminating the slug test can significantly reduce the overall time
Authors
E.A. Greene, A.M. Shapiro
Simulation of variable-density flow and transport of reactive and nonreactive solutes during a tracer test at Cape Cod, Massachusetts
A multispecies numerical code was developed to simulate flow and mass transport with kinetic adsorption in variable-density flow systems. The two-dimensional code simulated the transport of bromide (Br−), a nonreactive tracer, and lithium (Li+), a reactive tracer, in a large-scale tracer test performed in a sand-and-gravel aquifer at Cape Cod, Massachusetts. A two-fraction kinetic adsorption model
Authors
Hubao Zhang, Frank W. Schwartz, Warren W. Wood, S. P. Garabedian, D.R. LeBlanc
Simulated effects of irrigation on salinity in the Arkansas River Valley in Colorado
Agricultural irrigation has a substantial impact on water quantity and quality in the lower Arkansas River valley of southeastern Colorado. A two-dimensional flow and solute transport model was used to evaluate the potential effects of changes in irrigation on the quantity and quality of water in the alluvial aquifer and in the Arkansas River along an 17.7 km reach of the fiver. The model was cali
Authors
K. Goff, M.E. Lewis, M.A. Person, Leonard F. Konikow
How good are estimates of transmissivity from slug tests in fractured rock?
Slug tests in fractured rock usually are interpreted with models that assume homogeneous formation properties, even though hydraulic properties of fractures can vary by many orders of magnitude over the length of boreholes. To investigate the impact of heterogeneity on the interpretation of slug tests in fractured rock, slug tests were conducted over large intervals of boreholes in crystalline roc
Authors
A.M. Shapiro, P. A. Hsieh
Colloid particle sizes in the Mississippi River and some of its tributaries, from Minneapolis to below New Orleans
An on-board technique was developed that combined discharge-weighted pumping to a high-speed continuous-flow centrifuge for isolation of the particulate-sized material with ultrafiltration for isolation of colloid-sized material. In order to address whether these processes changed the particle sizes during isolation, samples of particles in suspension were collected at various steps in the isolati
Authors
C.E. Rostad, T.F. Rees, S.R. Daniel
Models of metal binding structures in fulvic acid from the Suwannee River, Georgia
Fulvic acid, isolated from the Suwannee River, Georgia, was assessed for its ability to bind Ca2+, Cd2+, Cu2+, Ni2+, and Zn2+ ions at pH 6 before and after extensive fractionation that was designed to reveal the nature of metal binding functional groups. The binding constant for Ca2+ ion had the greatest increase of all the ions in a metal binding fraction that was selected for intensive character
Authors
J. A. Leenheer, G.K. Brown, P. MacCarthy, S.E. Cabaniss
Methyl mercury dynamics in littoral sediments of a temperate seepage lake
The sites and rates of methyl mercury (MeHg) production and transport in littoral zone sediments were investigated at Pallette Lake in northern Wisconsin. In littoral areas where groundwater inflow occurs, sulfate supply from groundwater creates profiles of electron acceptors (sulfate) and donors (methane, sulfide) that are reversed from those found in sediments whose sulfate supply is delivered f
Authors
D. P. Krabbenhoft, C.C. Gilmour, J.M. Benoit, Christopher L. Babiarz, A.W. Andren, J.P. Hurley
Interaction between stream temperature, streamflow, and groundwater exchanges in alpine streams
Four alpine streams were monitored to continuously collect stream temperature and streamflow for periods ranging from a week to a year. In a small stream in the Colorado Rockies, diurnal variations in both stream temperature and streamflow were significantly greater in losing reaches than in gaining reaches, with minimum streamflow losses occurring early in the day and maximum losses occurring ear
Authors
James E. Constantz
Analysis of transient storage subject to unsteady flow: Diel flow variation in an Antarctic stream
Transport of dissolved material in streams and small rivers may be characterized using tracer-dilution methods and solute transport models. Recent studies have quantified stream/substream interactions using models of transient storage. These studies are based on tracer-dilution data obtained during periods of steady flow. We present a modeling framework for the analysis of transient storage in str
Authors
R.L. Runkel, Diane M. McKnight, E.D. Andrews
Impact of the 1993 flood on the distribution of organic contaminants in bed sediments of the Upper Mississippi River
The 1500 km Upper Mississippi River (UMR) consists of 29 navigation pools and can be divided into the upper reach (pools 1-4), the middle reach (pools 5-13), and the lower reach (pools 14-26). Comparison of composite bed sediment samples collected from the downstream third of 24 pools before and after the 1993 UMR flood provides fieldscale data on the effect of the flood on sediment organic compou
Authors
L. B. Barber, J.H. Writer
Strain IMB-1, a novel bacterium for the removal of methyl bromide in fumigated agricultural soils
A facultatively methylotrophic bacterium, strain IMB-1, that has been isolated from agricultural soil grows on methyl bromide (MeBr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. Phylogenetic analysis of its 16S rRNA gene sequence indicates that strain IMB-1 classes in the alpha subgroup of the class Proteobacteria and is closely related to me
Authors
Hancock T.L. Connell, A.M. Costello, M.E. Lidstrom, R.S. Oremland