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Selected Issues in Environmental Economics
2001
Sarhan, Alaa A. (Egyptian Forum on Environment and Sustainable Development, Cairo (Egypt))
Control of Water Pollution from Agriculture
2001
Hamdy, A. (Centre International de Hautes Etudes Agronomiques Méditerranéennes, Bari (Italy). Institut Agronomique Méditerranéen)
Criteria for Protecting the Groundwater in Egypt
2001
Fadlelmawla, A.A.
The vitality, vulnerability, and evidence of pollution of the groundwater resources in Egypt are all necessitating the protection of the valuable resource. However, due to the historic dependence on Nile water and also due to the misconception of complete natural protection, major actions regarding regulation and protection were restricted to surface water. This situation resulted in total absence of a framework for the management of groundwater protection in the country. Experiences in Europe and the United States have shown that groundwater protection is technically a complex issue, requiring the preparation of a conceptual framework that addresses/identifies the main technical issues/tools of the protection. In this paper, a description of the criteria proposed for the groundwater protection management in Egypt is given. The criteria were prepared in the form of guidelines constituting of a conceptual framework and the technical tools needed for achieving the proposed framework. Along with the technical tools, recommendations regarding their application and other specific protection issues were given based on pilot area application.
Show more [+] Less [-]Distribution of ammonium-N in the water-soil interface of a surface-flow constructed wetland for swine wastewater treatment
2001
Szogi, A.A. | Hunt, P.G.
Most livestock wastewaters treated in constructed wetlands are typically rich in ammonium N. The objective of this study was to evaluate the soil-water ammonium distribution and the diffusive flux through the soil-water interface. Wetland system 1 (WS1) was planted to rush and bulrushes, and wetland system 2 (WS2) was planted to bur-reed and cattails. Nitrogen was applied at a rate of 2.5 g m-2 d-1. Interstitial soil water was sampled at 9, 24, 50, and 70 m from the inlet. In both wetlands, we found that NH4+ diffusion gradient and N losses were highest in the wetland system with lowest water depth. From other studies, we knew that shallower depths may have promoted a more effective interfacing of nitrifying and denitrifying environments. In turn, this N reduction in the water column may be the reason for steady NH4+-N upward diffusion fluxes. The assumed mechanism for N removal has been nitrification and denitrification but ammonia volatilization could also have occurred. Although diffusion may explain a significant portion of the material transport between the soil-water interface, the large differences in concentrations between outlet and inlet need further explanation.
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