خيارات البحث
النتائج 131 - 140 من 212
Sustainable development and fresh water management in industry
2001
El-Zarka, M. (Director of Environmental and Development Unit - Social Found for Development, Cabinet of Ministers, (Egypt))
Design of Water Quality Monitoring Network
2001
Khalek, M.A.A.(National Water Research Centre, Cairo (Egypt). Drainage Research Institute)
Initial Environmental Evaluation Case Study Irrigation Improvement Project (Egypt)
2001
Tawfic, T. A. (Central Laboratory for Environmental Quality Monitoring, Cairo (Egypt))
Abatement of Polar Organics in Natural Wetlands and Rivers. Analitycal Methods
2001
Headley, J. (National Water Research Centre, Cairo (Egypt)) | Tawfic, T. A.
Here are described three innovative and complementary methods for the characterization of polar organics in natural waters. A simple and rugged GC/MS procedure is shown to be well suited for the determination of sulfolane, (tetrahydrothiophene 1,1-dioxide, C4H8O2S; a water miscible chemical used in the sweetening of sour-gas) a compound that is known to be readily sequested by wetland vegetation. In contrast, LC/MS employing electrospray ionization is ideal for the quantification of two other classes of polar chemicals, namely (a) alkanolamines in vegetation and (b) mixtures of naphthenic acids in natural waters in oilsands regions of Northern Alberta, Canada. The modem techniques take advantage of quite simple extraction procedures, with no need for derivatization steps and exploit the polar nature of the chemicals to separate the analytes from high back ground non-polar components. For the alkanolamines, MS/MS is a prerequisite for obtaining diagnostic product ion scans of the molecular ion formed under soft-ionization conditions.
اظهر المزيد [+] اقل [-]Water Quality and Hydrology for Lakes
2001
El-Zawahry, A.
Water Quality Database Management
2001
Salah, A. M. (Central Laboratory for Environmental Quality Monitoring, Cairo (Egypt)) | Tawfic, T. A.
Effect of Agricultural non-point Source Contaminants on Canadian Great Lakes Coastal Marshes
2001
Millette, J.A. (National Water Research Centre, Cairo (Egypt)) | Gutzman, D.W. | Gamble, D.S. | Bourgoin, B.P. | Mudroch, A. | Day, K. | Roshon, R.
As part of the Canadian Great Lakes Action Plan, the transport and effect of non-point source agricultural contaminants in wetlands were evaluated. Due to the broad scope of this study, the abilities of many individuals with different domains of expertise were employed. Stages of the study reported here include: 1) Survey of cropping and pesticide/fertilizer practices of farms in the selected watersheds; 2) Sampling and analysis of creek water and sediments for pesticides and other parameters; 3) Study of the reversible "loss" of pesticides by adsorptive and diffusive interaction with sediment particles; 4) Investigation of the effect of the agricultural contaminants on macrophytes and invertebrates. Among the findings of this work were the detection of some pesticides years after their last use as well as the presence of microorganisms, in all creek sediments tested, capable of rapidly and completely mineralizing atrazine.
اظهر المزيد [+] اقل [-]Control of Water Pollution from Agriculture
2001
Hamdy, A. (Centre International de Hautes Etudes Agronomiques Méditerranéennes, Bari (Italy). Institut Agronomique Méditerranéen)
Water-rock Interaction and Related Groundwater Quality in Coastal Aquifers
2001
Fidelibus, M. D. (Bari Politechnics, Bari (Italy). Dept. of Civil and Environmental Engineering)
Water Quality Modelling
2001
El-Sayed, A. (Drainage Research Institute, Open Drainage Dept.)