خيارات البحث
النتائج 31 - 40 من 101
Development of a state effluent charge system
1972
The Economic impact of pollution control
1972
Evaluation of beef cattle feedlot waste management alternatives
1972
Butchbaker, A. F.
Role of bacteria in the nitrogen cycle in lakes
1972
McCoy, Elizabeth
Biological nitrification as contributing nitrite and nitrate to lakes and streams was explored by determining: nitrifiers, growth sites and activity; denitrifying bacteria numbers and their potential activity as opposing nitrification; field data on nitrite-nitrogen and nitrate-nitrogen in terms of nitrifier and denitrifier populations. Biological nitrification, both heterotrophic and autotrophic, was demonstrated. Even though opposing processes, nitrification and denitrification can coexist in close succession or in adjoining microhabitats. Field values for nitrate-nitrogen and nitrite-nitrogen vary considerably and must be viewed as net values at any given time. Thirteen species of fishes varied greatly in resistance to nitrite-nitrogen. Nitrite toxicity may influence fish species dominance in a eutrophic lake.
اظهر المزيد [+] اقل [-]The effect of chlorination on selected organic chemicals
1972
The effects of artificial aeration on lake ecology
1972
Fast, Arlo W.
Trickling filter treatment of fruit processing waste waters
1972
Rose, Walter W. | Mercer, Walter A.
Extensions of mathematical programming for regional water quality management
1972
Nitrate in the unsaturated zone under agricultural lands
1972
Pratt, P. F. (Parker F)
Use of general equillibrium in regional water resource planning
1972
Poirier, J. Eugène | Harrington, John M.
