959 resultados para Environmental Engineering
Resumo:
Cover title.
Resumo:
Cover title: Lower Columbia River environmental radiological survey in Oregon, 1961-1963.
Resumo:
"EPA-R2-73-176."
Resumo:
Mode of access: Internet.
Resumo:
Mode of access: Internet.
Resumo:
The city of Marion has applied to the Illinois EPA for Section 401 water quality certification to construct a 1,172 surface acre, raw water impoundment reservoir on Sugar Creek, southeast of Creal Springs, Williamson County, Illinois. This proposal and the impacts are described in the Final EIS, DSI, and DSII. The proposed project will involve the construction of a reservoir on Sugar Creek and the mitigation for affected wetlands and jurisdictional waters of the United States.
Resumo:
Subtitle on cover: Their effects on planning, construction, and operation of Bureau of Reclamation projects.
Resumo:
In wastewater treatment plants with anaerobic sludge digestion, 15-20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant significantly reduces the nitrogen load of the activated sludge system. Two biological applications are considered for nitrogen elimination: (i) classical autotrophic nitrification/heterotrophic denitrification and (ii) partial nitritation/autotrophic anaerobic ammonium oxidation (anammox). With both applications 85-90% nitrogen removal can be achieved, but there are considerable differences in terms of sustainability and costs. The final gaseous products for heterotrophic denitrification are generally not measured and are assumed to be nitrogen gas (N-2). However, significant nitrous oxide (N2O) production can occur at elevated nitrite concentrations in the reactor. Denitrification via nitrite instead of nitrate has been promoted in recent years in order to reduce the oxygen and the organic carbon requirements. Obviously this achievement turns out to be rather disadvantageous from an overall environmental point of view. On the other hand no unfavorable intermediates are emitted during anaerobic ammonium oxidation. A cost estimate for both applications demonstrates that partial nitritation/anammox is also more economical than classical nitrification/denitrification. Therefore autotrophic nitrogen elimination should be used in future to treat ammonium-rich sludge liquors.
Resumo:
Moisture transport and dimensional change during wood drying or wetting processes were analyzed based on pictures from an environmental scanning electron microscope (ESEM). This provides quantitative relationships between dimensional changes of total area, cell wall, and lumen, and moisture content for earlywood and latewood. Earlywood and latewood behave similarly but show some quantitative differences. The overall outcome for sections containing both kinds of wood seems to be dominated by the latewood behavior. The observed strain behavior of wood during drying is anisotropic in ways that are inconsistent with explanations solely related to microfibril orientation or earlywood/latewood interactions and more likely may be influenced by ray tracheids.