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Résultats 201-210 de 213
A research project to identify by remote sensing particulate size and distribution for air pollution assessment
1971
Fuller, C. E.
Chlorinated municipal waste toxicities to rainbow trout and fathead minnows
1971
Basch, R. E.
Effect of chlorinated municipal wastes on fish life and laboratory findings of earlier researchers were assessed in separate studies at four Michigan municipal wastewater treatment plants. Tolerance levels and river length below each plant outfall rendered unavailable to resident fish populations were determined. Ten rainbow trout (Salmo gairdneri) and ten fathead minnows (Pimephales promelas), previously acclimated, were held 96 hours in live boxes in the stream above and below these outfalls. Fish held below these outfalls were subjected to both chlorinated and non-chlorinated exposures during effluent discharge. Test waters were monitored chemically and bacteriologically during fish exposure. Total residual chlorine concentrations below three plants were toxic to rainbow trout at distances up to 0.8 mile. Fathead minnows appeared adversely affected up to 0.6 mile downstream in two of the four plants. Total residual chlorine concentrations less than 0.1 mg/l were toxic to fathead minnows. Rainbow trout 96-hour total residual chlorine TL-50 concentration below two plants was 0.023 mg/l.
Afficher plus [+] Moins [-]Techniques to reduce nitrogen in drainage effluent during transport
1971
A system for industrial waste treatment RD & D project priority assignment
1971
Bramer, Henry C. | DeHaven, Robert C. | Leavitt, Alvan W.
Denitrification by anaerobic filters and ponds
1971
Infiltration rates and groundwater quality beneath cattle feedlots, Texas High Plains
1971
Miller, William D.
Detailed field and laboratory studies of five feedlots were conducted to determine field seepage rates and distributive geometry of infiltrated runoff. Practical field seepage rates at these sites ranged from 2 to 20 feet/year. Dispersal rates of ions in the groundwater zone varied from 45 to 400 feet/year. Nitrogen (NO₃, NO₂, NH₄, Org-N) and common chemical parameters (Ca, Mg, Na, K, Cl, SO₄, TDS, pH, and conductance) were determined in cores and groundwater samples; based on groundwater analyses from 80 Texas High Plains feedlots, rates of concentration of NO₃-N and Cl in groundwater beneath feedlots range from 0.07 to 0.4 p.p.m. per year, and average 0.17 p.p.m. per year.
Afficher plus [+] Moins [-]Brass wire mill process changes and waste abatement, recovery and reuse
1971
Lancy, Leslie E. | Forbes, Charles A.
The report describes process changes and waste treatment, recovery, and reuse facilities installed by Volco Brass and Copper Company, Kenilworth, New Jersey. The plant produces 75 tons of wire per day. An electrolytic system was installed to recover copper from the spent primary pickle solution and to regenerate the sulfuric acid for reuse. A hydrogen peroxide bright pickle replaced the chromate and fluoride bright pickles previously used. Copper from the bright pickle is also recovered in the electrolytic system. The electrolytic copper is reused on location in casting. An integrated copper treatment system was installed to treat bright pickle drag-out. Sludge from the integrated system is recovered for sale. Rinse water consumption was reduced from 150 gpm to 10 gpm. Former discharges of chromium, ammonium, and fluoride ions have been eliminated. Cost and operating data and effluent analyses are presented.
Afficher plus [+] Moins [-]Managing the environment: international economic cooperation for pollution control
1971
Outgrowth of a conference organized by the Atlantic Council of the United States and the Battelle Memorial Institute, held Jan. 15-17, 1971, at the Dept. of State, Washington, D.C.
Afficher plus [+] Moins [-]The effects of various gas atmospheres on the oxidation of coal mine pyrites
1971
Robins, John D. | Troy, Joseph C.
Experiments up to 150 days in length were conducted to study the acid production rate of coal mine pyrites under various gas atmospheres. The gas atmospheres studied were air, nitrogen, methane, and carbon dioxide. The lower limits of the oxidation process were studied by introducing small amounts of oxygen along with the inert blanketing gas and by studying the effects of deaerated versus air saturated feedwater. Acid production was proportional to the available oxygen partial pressure. The acid parameters monitored continued to change and had not completely reached a steady state by the termination of the work. The acid production of nitrogen blanketed pyrite decreased to less than 1% of that of identical columns under air atmosphere. Nitrogen and methane gases were equally effective in reducing acid production. Both of these gases were slightly more effective than carbon dioxide. A large amount of detailed experimental data is presented.
Afficher plus [+] Moins [-]Joint air pollution study of St. Clair-Detroit river areas for International Joint Commission, Canada and the United States
1971