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Resultados 71-80 de 101
Screening/flotation treatment of combined sewer overflows
1972
Mason, Donald G. | Gupta, Mahendra K.
The report documents a study to develop a treatment system for combined sewer overflows. The processes of chemical oxidation, screening, dissolved-air flotation, and disinfection were evaluated in the laboratory. A 5 MGD demonstration system was designed, installed and evaluated. Suspended solids and volatile suspended solids removal in the range of 65-80% were consistently obtained at influent concentrations of 150 to 600 mg/l. BOD and COD removals were slightly lower at 55 to 65% for influent concentrations of 50 to 500 mg/l. Addition of chemical flocculents (ferric chloride and a cationic polyelectrolyte) was necessary to obtain these removals. Without the use of chemical flocculents, removal of BOD, COD, suspended solids, and volatile suspended solids were all in the range of 40-50%. The screening flotation system provided sufficient detention time (difference 15 minutes) for adequate disinfection with hypochlorite salts. Cost estimates are presented.
Mostrar más [+] Menos [-]Combined steel mill and municipal wastewaters treatment
1972
Smith, William M. (William Martin)
A systems evaluation was made to determine the feasibility and economics of treating selected steel mill and sanitary wastewaters in a municipal sewage treatment plant. The project was Phase I of a three phase program to demonstrate that industries and municipalities through cooperative action can combine their wastewaters and attain their individual treatment goals in an efficient and economical manner. Detailed field work was carried out at the steel plant and the total sewage plant treatment system. Selected steel plant wastes were combined with municipal wastes and evaluated in both batch and continuous treatability bench scale studies. The investigation revealed that it is technically and economically feasible to co-treat selected steel plant wastes with municipal wastewaters.
Mostrar más [+] Menos [-]Research needs for irrigation return flow quality control
1972
Skogerboe, Gaylord V. | Law, James P.
There are a multitude of research needs regarding irrigation return flow quality, but only the specific research needs required to undertake an effective control program are described. These research needs include irrigation practices, soil-plant-salinity relationships, leaching requirements, prediction of subsurface return flow, cultural practices, irrigation scheduling, treatment of return flows, economic evaluations, and institutional control methods.
Mostrar más [+] Menos [-]Dispersion and forecasting of air pollution
1972
Lake Superior periphyton in relation to water quality | Periphyton
1972
Olson, Theodore A. | Odlaug, Theron O. (Theron Oswald)
Laboratory and field studies were conducted to evaluate the importance of periphyton in western Lake Superior with special reference to the make-up and distribution of the periphyton growths and to the overall importance of productive capacity of this assemblage of organisms. The taxonomic portion of the investigation indicated that over 90% of the total number of organisms were diatoms and that the phyla to which these diatoms belonged were the Chrysophyta, the Chlorophyta, and the Cyanophyta. Predominant genera were Synedra, Achnanthes, Navicula, Cymbella, and Gomphonema. In many respects, the periphyton of Lake Superior was similar to that found in streams and there was evidence that the interrelated factors that affected periphyton growths were temperature, light intensity, depth of water, water movements, nutrient levels, and the type of substrate.
Mostrar más [+] Menos [-]Aquatic dryopoid beetles (Coleoptera) of the United States
1972
Brown, Harley P. (Harley Proctor),
Freshwater planarians (Turbellaria) of North America
1972
Kenk, Roman,
Freshwater polychaetes (Annelida) of North America
1972
Foster, Nancy (Nancy Marie),
Economic implications of water pollution abatement in family farm livestock production
1972
Van Arsdall, Roy Neuman | Johnson, J. B.
Caustic dry peeling of cling peaches to reduce water pollution
1972
Gray, Leo R. (Leo Roger) | Hart, Marcus R.