Skip to main content
U.S. flag

An official website of the United States government

Publications

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

Filter Total Items: 3740

Formation of methane and carbon dioxide from dimethylselenide in anoxic sediments and by a methanogenic bacterium

Anaerobic San Francisco Bay salt marsh sediments rapidly metabolized [14C]dimethylselenide (DMSe) to 14CH4 and 14CO2. Addition of selective inhibitors (2-bromoethanesulfonic acid or molybdate) to these sediments indicated that both methanogenic and sulfate-respiring bacteria could degrade DMSe to gaseous products. However, sediments taken from the selenium-contaminated Kesterson Wildlife Refuge pr
Authors
Ronald S. Oremland, Jon P. Zehr

A new formula for the analytical solution of the radial dispersion problem

A new formula is presented for the analytical solution of the radial dispersion problem, which analyzes the dispersive transport of a tracer in radial flow from a recharge well. This formula is simpler than a solution presented by previous investigators, but the two solutions are shown to be equivalent. Because the analytical solution consists of an integral of an oscillatory function, it is evalu
Authors
Paul A. Hsieh

Chemical qualities of water that contribute to human health in a positive way

The emphasis on harmful substances that may occur in potable waters has almost obscured the fact that important beneficial constituents are commonly present.The chemical substances in water that make positive contributions to human health act mainly in two ways: (i) nutritionally, by supplying essential macro and micro elements that the diet (excluding water) may not provide in adequate amounts (f
Authors
Howard C. Hopps

Groundwater transport of strontium 90 in a glacial outwash environment

As part of the investigation of groundwater contamination at a uranium-scrap recovery plant at Wood River Junction, Rhode Island, laboratory experiments led to the development of a model for predicting the transport of strontium 90 in glacial outwash sediments based on an approximate mechanism for ion exchange. The multicomponent system was simplified to two components by regarding all exchangeabl
Authors
Kenneth L. Kipp, Kenneth G. Stollenwerk, David B. Grove

Modeling contamination of shallow unconfined aquifers through infiltration beds

We model the transport of a simply reactive contaminant through an infiltration bed and underlying shallow, one-dimensional, unconfined aquifer with a plane, steeply sloping bottom in the assumed absence of dispersion and downgradient dilution. The effluent discharge and ambient groundwater flow under the infiltration beds are presumed to form a vertically mixed plume marked by an appreciable radi
Authors
D.W. Ostendorf

Predictive accuracy of a ground-water model--Lessons from a postaudit

Hydrogeologic studies commonly include the development, calibration, and application of a deterministic simulation model. To help assess the value of using such models to make predictions, a postaudit was conducted on a previously studied area in the Salt River and lower Santa Cruz River basins in central Arizona. A deterministic, distributed-parameter model of the ground-water system in these all
Authors
Leonard F. Konikow

Physio-chemical processes affecting copper, tin and zinc toxicity to algae: A review

This chapter focuses on the physic-chemical processes affecting copper, zinc, and tin toxicity to algae. Both Cu and Zn are essential algal micronutrients, cofactors in numerous biochemical processes. The availability of a nutrient or toxic substance can be significantly affected by precipitation. Methods for modeling the effects of adsorption–desorption reactions have been previously reviewed. Us
Authors
James S. Kuwabara

Aqueous dissolution, solubilities and thermodynamic stabilities of common aluminosilicate clay minerals: Kaolinite and smectites

Determinations of the aqueous solubilities of kaolinite at pH 4, and of five smectite minerals in suspensions set between pH 5 and 8, were undertaken with mineral suspensions adjusted to approach equilibrium from over- and undersaturation. After 1,237 days, Dry Branch, Georgia kaolinite suspensions attained equilibrium solubility with respect to the kaolinite, for which Keq = (2.72 ± 0.35) × 107.
Authors
Howard M. May, D.G. Klnniburgh, P.A. Helmke, Melanie L. Jackson

Effect of ground-water recharge on configuration of the water table beneath sand dunes and on seepage in lakes in the sandhills of Nebraska, U.S.A.

Analysis of water-level fluctuations in about 30 observation wells and 5 lakes in the Crescent Lake National Wildlife Refuge in the sandhills of Nebraska indicates water-table configuration beneath sand dunes in this area varies considerably, depending on the configuration of the topography of the dunes. If the topography of an interlake dunal area is hummocky, ground-water recharge is focused at
Authors
T. C. Winter