Affiner votre recherche
Résultats 1-10 de 11
COMPARING SOLID WASTE MANAGEMENT SYSTEMS FOR SUPERMARKETS Texte intégral
1974
Ricker, Harold S.
Proceedings of the International Conference on Land for Waste Management =
1974
Tomlinson, Jocelyn
BEEF WASTE MANAGEMENT ECONOMICS FOR MINNESOTA FARMER-FEEDERS Texte intégral
1974
Pherson, Carl L.
Planning for the management of solid waste materials in rural areas
1974
Carley, D. H.
Planning for the management of solid waste materials in rural areas
1974
Carley, D. H.
Production theory and community services planning: application to solid waste disposal
1974
Knutson, M. | Boehlje, M. | Schreiner, D.
Extract: A basic management responsibility in community service planning is to evaluate alternative methods of providing various public goods and services such as transportation services, sewage and solid waste disposal, and water for home and industry. these alternative methods frequently involve new or different technologies and various combinations of inputs such as capital and labor. the purpose of this discussion is to develop and relate the concepts of production economics to the provision of community services. the application of these concepts to the allocation of resources in solid waste disposal will provide an empirical example of the type of analysis required. these concepts should be useful to community planners and public works managers in making and justifying resource allocation decisions.
Afficher plus [+] Moins [-]Preliminary investigation into the rheology of dairy shed waste Texte intégral
1974
Dakers, A. J.
With the introduction of stricter control on the final disposal of all forms of farm waste, its transportation is becoming an everyday component of farm management. In the past and at present the design of such transportation systems has been and is being based on criteria for transportation of fresh water with little appreciation of the differences that may or may not exist. Certain research workers have found this difference to be quite significant (13, 15, 31). Estep (36) has suggested that manure pump installations should be designed for a friction loss 10% higher than for water. Grimm et ale (12) found that with total solids (T.S) less than 35,000ppm pressure loss was less than for water. Thus it might be concluded that a considerable amount of work is required before accurate flow characteristics of manure slurries can be understood.
Afficher plus [+] Moins [-]Decision-makers guide in solid waste management | Solid waste management | Technical Report Archive & Image Library (TRAIL)
1974
Colonna, Robert A.
Nitrogen Loss from Manure as Influenced by Moisture and Temperature Texte intégral
1974
Adriano, D. C. | Chang, A. C. | Sharpless, R.
Soil temperature and moisture are important in cattle waste management. The effects of these two variables on N losses from different rates of applied manure were studied under greenhouse conditions at two soil moisture (60 and 90% of water saturation percentage, WSP) and two soil temperature (10 and 25C) levels. The manure rate did not have a significant effect on the percentage of loss of applied N. At 10C, the average losses of applied N were 26 and 39%, respectively, for the 60 and 90% moisture levels. Higher losses of 40 and 45% were obtained for the 60 and 90% levels, respectively, at 25C. Results suggest that these losses occurred largely through volatilization of NH₃. Under conditions where significant nitrification occurred, there were greater concentrations of electrolytes associated with reduction in pH indicating that leaching of NO₃⁻ cannot be divorced from soluble salts in manure disposal areas. With N losses approaching 50% of the applied N, large quantities of N are being volatilized to the atmosphere over large and concentrated dairy and feedlot areas.
Afficher plus [+] Moins [-]Characterization and treatment of urban land runoff
1974
Colston, Newton V.
"Urban land runoff from a 1.67 square-mile urban watershed in Durham, North Carolina, was characterized with respect to annual pollutant yield. Regression equations were developed to relate pollutant strength yield. Regression equations were developed to relate pollutant strength to hydrograph characteristics. Urban land runoff was found to be a significant source of pollution when compared to the raw municipal waste generated within the study area. On an annual basis, the urban runoff yield of COD was equal to 91 percent of the raw sewage yield, the BOD yield was equal to 67 percent, and the urban runoff suspended solids yield was 20 times that contained in raw municipal wastes for the same area. Downstream water quality was judged to be controlled by urban land runoff 20 percent of the time (i.e., the pounds of COD from urban land runoff was approximately 4-1/2 times the pounds of COD from raw sewage.) It is conceivable that critical water quality conditions are not typified by the 10-year, 7-day flow, but by the period immediately following low-flow periods when rainfall removes accumulated urban filth into the receiving watercourse, greatly increasing the pollutant load while not substantially increasing water quantity. Specific urban land use did not appear to influence the quality of urban land runoff. The applicability and effectiveness of plain sedimentation and chemical coagulation of urban land runoff was evaluated. Plain sedimentation was found to remove an average of 60 percent of the COD, 77 percent of the suspended solids, and 53 percent of the turbidity. Cationic polyelectrolytes and inorganic coagulants were found to provide significant residual removal increases over plain sedimentation. Alum was judged the best coagulant and produced average removals of COD, suspended solids, and turbidity of 84, 97, and 94 percent, respectively. The EPA Storm Water Management Model (SWMM) was evaluated with respect to actual conditions as measured in the field. The model was judged to predict peak hydrograph flows and total hydrograph volumes with reasonable accuracy; however, it was not judged effective for predicting pollutant concentrations. In urban drainage basins, investments in upgrading secondary municipal waste treatment plants without concomitant steps to moderate the adverse effects of urban land runoff are questionable in view of the apparent relative impact of urban land runoff on receiving water quality. This report was submitted in fulfillment of project number 11030 HJP by the North Carolina Water Resources Research Institute under partial sponsorship of the Office of Research and Development, Environmental Protection Agfency. Work was completed as of September 1, 1973"--Page iv.
Afficher plus [+] Moins [-]