Publications

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...

No abstract available

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

A controlled and renewable release fertilization system is proposed that employs NH4 saturated clinoptilolite to aid in the dissolution of phosphate rock (apatite), and thereby to release soluble N, P, and exchangeable Ca for uptake by plants. The system is based on the principle that exchangers can sequester Ca ions released by the dissolution of apatite, thereby leading to further...

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...

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...

No abstract available.

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...

No abstract available.

A microcomputer coupled to a video digitizer was used to develop methods for measuring areas of tree rings and for delineating and measuring microscopic anatomical features. Digitally imaged areas of individual rings of a loblolly pine cross section were within 2.6% of areas measured with a planimeter and were more accurate than areas calculated from radius widths. Various anatomical...

Water budget and isotopic analyses of water in the eastern Snake River Plain aquifer system confirm that most, if not all, of the water is local meteoric in origin. Solute mass-balance arguments suggest that ∼5 × 109 moles of calcite and 2.6 × 109 moles of silica are precipitated annually in the aquifer. Isotopic evaluations of calcite and petrographic observation of silica support the...

Changes in salinity and nitrate concentration in groundwater and surface water in the semiarid Arkansas River valley of southeastern Colorado, USA were related primarily to irrigation practices. Water is applied to fields by flood irrigation through ditches and furrows. Irrigation water is derived in nearly equal amounts from surface water and groundwater pumped from the shallow alluvial...