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Theodore A. Ehlke

Publications and source records attributed to Theodore A. Ehlke.

7 recordsLinked to original sources
USGS2007

Laboratory comparison of polyethylene and dialysis membrane diffusion samplers

The ability of diffusion samplers constructed from regenerated cellulose dialysis membrane and low density, lay flat polyethylene tubing to collect volatile organic compounds and inorganic ions was compared in a laboratory study. Concentrations of vinyl chloride, cis ‐1, 2‐dichloroethene, bromochloromethane, trichloroethene, bromodichloromethane, and tetrachloroethene collected by both types of diffusion samplers reached equilibrium with the concentrations of these compounds in test solution within three days. Concentrations of bromide and iron collected by the dialysis membrane diffusion samplers reached equilibrium with the concentrations of these compounds in a test solution within three to seven days. No detectable concentrations of bromide or iron were found in polyethylene diffusion samplers even after 21 days. No measurable concentrations of aluminum, arsenic, barium, cadmium, chromium, iron, mercury, manganese, nickel, and lead, or sulfide, were leached out of dialysis membrane samplers over seven days. Compared with using a gas‐tight syringe to sample the diffusion sampler, clipping the bag and pouring the water sample into a sample vial resulted in only a small 6.2% average loss of volatile organic compounds. Dialysis membrane diffusion samplers offer promise for use in sampling ground water for inorganic constituents as well as volatile organic compounds.

Groundwater Monitoring & Remediation↗
USGS1979

The effect of nitrification in the oxygen balance of the Upper Chattahoochee River, Georgia

Oxygen consumption as a result of nitrification, and carbonaceous bacterial oxidation were compared in a 108 kilometer reach of the Chattahoochee River, Georgia. Nitrogenous and carbonaceous oxygen consumption were separated by using an inhibitor of nitrification 1-allyl-2-thiourea. The comparison was conducted in the laboratory using samples collected from the water column. Nitrification accounted for 38 to 52 percent of the total oxygen consumption. Nitrifying bacteria were enumerated from the same reach of the river. The population of Nitrosomonas ranged from 10 to 1,000 per milliliter in the water column and 100 to 100,000 per gram of benthic sediment. The nitrobacter population ranged from 10 to 100 per milliliter in the water column and 100 to 1,000 per gram in the benthic sediment. The concentration of ammonium, nitrite, and nitrate as N was determined from water samples collected throughout the study reach. The average rate of ammonium disappearance and of nitrate appearance was 0.02 milligram per liter per hour of flow time. (Woodard-USGS)

Georgia↗
USGS1979

Effects of landfill leaching on water quality and biology of a nearby stream, South Cairo, Greene County, New York

A 1-kilometer stream reach receiving leachate-enriched water from a small municipal landfill in Greene County, N.Y., was studied from 1971-75 to document streamflow rates and chemical quality of the stream and ground water. The distribution of benthic invertebrates and microorganisms in the stream above the landfill was markedly different from that below it; the difference is attributed to the inflow of leachate. The Trichoptera, Ephemeroptera, and Nematomorpha have been eliminated from the reach adjacent to and below the landfill and have been replaced by large numbers of Tendipedidae and Niadidae. Certain chemical constituents, especially iron and manganese, were extremely concentrated in the ground water immediately beneath the streambed. The elevated concentrations of these and other metals may be the direct cause of the abrupt faunal shift. Algae were replaced by large masses of the iron bacterium Leptothrix in the stream reach below the landfill. (Kosco-USGS)

Water-Resources Investigations Report↗
USGS1974

Comparison of bacterial and phytoplankton populations under natural and laboratory conditions

Bacteria and blue-green algae were isolated from Oneida Lake, N.Y., and other sources. The blue-green algae Anabaena flos-aquae , Anabaena spiroides , Gloeotrichia echinulata , and Microcystis aeruginosa were grown under laboratory conditions and were separated into unialgal cultures. The bacterial population living in association with the unialgal blue-green algae differed significantly from the bacterial flora of Oneida Lake. Bacillus , Pseudomonas , Aeromonas , and Zoogloea were the most frequently occurring genera of bacteria from the lake, whereas Flavobacterium , Achromobacter , and Pseudomonas were the most common bacteria isolated from laboratory blue-green cultures. Nutritional and physiological characteristics of bacteria isolated in the laboratory were more uniform than those isolated from the lake.

Journal of Research of the U.S. Geological Survey↗
USGS1973

Microbiological aspects of ground-water recharge injection of purified unchlorinated sewage effluent at Bay Park, Long Island, N. Y.

Unchlorinated, tertiary-treated sewage effluent was injected through a well at Bay Park, Long Island, N.Y., into a sand aquifer at a rate of 340 gpm for 10 days. Massive, biologically produced slime deposits formed in the filter pack immediately adjacent to the well screen. Observed head buildup in the recharge well was correlated with the formation of these deposits. Comparison of results from this test with results of earlier tests suggests that formation of these deposits may be avoided by addition of chlorine to the injectant.

New York↗