Geology topics

Gerald L. Feder

Publications and source records attributed to Gerald L. Feder.

3 recordsLinked to original sources

USGS1983

Complexation of copper by aquatic humic substances from different environments

The copper-complexing properties of aquatic humic substances isolated from eighteen different environments were characterized by potentiometric titration, using a cupric ion selective electrode. Potentiometric data were analyzed using FITEQL, a computer program for the determination of chemical equilibrium constants from experimental data. All the aquatic humic substances could be modelled as having two types of Cu(II)-binding sites: one with K equal to about 10 6 and a concentration of 1.0 ± 0.4 × 10 −6 M(mg C) −1 and another with K equal to about 10 8 and a concentration of 2.6 ± 1.6 × 10 −7 M(mg C) −1 . A method is described for estimating the Cu(II)-binding sites associated with dissolved humic substances in natural water based on a measurement of dissolved organic carbon, which may be helpful in evaluating chemical processes controlling speciation of Cu and bioavailability of Cu to aquatic organisms.

Science of the Total Environment↗

USGS1981

Toxicity of Mount St. Helens ash leachate to a blue-green alga

During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream sites within the watershed were compared with samples collected during the same season in previous years. No detectable changes were noted in chemical characteristics. Precipitation samples collected immediately after the June 12-13 ash fall ranged in specific conductance from 20 to 41 micromhos per centimeter at 25C and in pH from 4.0 to 4.3 pH units. Stream samples collected during the May-June period ranged in specific conductance from 18 to 28 micromhos per centimeter at 25C and in pH from 6.7 to 7.5 pH units. Volcanic-ash samples were collected and analyzed for particle size, chemical composition, and weight. Significant differences in particle size of ash were found in samples from two separate eruptions. (USGS)

Circular↗

USGS1981

Results of a reconnaissance water-quality sampling program of the Ogallala aquifer in Colorado, Kansas, Nebraska, Oklahoma, South Dakota, and Texas

Results of a reconnaissance water-quality sampling program of the Ogallala aquifer indicates the water generally is suitable for most uses. Fluoride and selenium were the only chemical constituents found to exceed the National Interim Primary Drinking Water Regulations in water from some of the wells. Unusually large silica concentrations in many of the water samples probably were due to the presence of amorphous silica in relatively young volcanic-ash deposits present in the aquifer. Because the greatest silica concentrations (as much as 65 milligrams per liter) occurred in the Northern part of the aquifer, the volcanic source was probably from the northwest.

Colorado, Kansas, Nebraska, Oklahoma, South Dakota↗