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Browsing by Author "Jones, J."

Now showing 1 - 3 of 3
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    Adsorption of organic compounds onto solids from aqueous solutions
    Wightman, James P.; Dole, Leslie R.; Jones, J.; King, Clarence A. (Water Resources Research Center, Virginia Polytechnic Institute and State University, 1971)
    The use of solids to remove pollutants is not novel in the sense that solids are used presently for this purpose. For example, the use of charcoal is well known, and the use of alumina in phosphate removal has been investigated. The removal of phenol from aqueous solutions on a variety of solids has been studied in this work. The rationale for this study is as follows. An aqueous solution containing a pollutant (phenol) is a three component system consisting of a solute (phenol) and solvent (water) in contact with a solid. The question arises, what about the removal of the pollutant by the solid? In many instances the kinds of solids that have been used are those which not only compete for the pollutant, but also compete for water. Thus, not only is the interaction between the pollutant and the solid important, but also the Interaction between the water and the sol id. In many systems, for example herbicides, insecticides, and phenol, there is a Iimited solute concentration, which means that there is a basic incompatability in the system to start with. Then as this solution is put in contact with a solid surface, the amount of pollutant and the amount of water removed become relevant. If the solid has an attraction for water in addition to the pollutant, water may be removed and block parts of the solid which could be effective in removing the pollutant. This study has been concerned with the adsorption of phenol from aqueous solutions on several solids chosen to alter the competition of water and phenol for the surface of the solid.
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    Analyzing changes in productivity and carrying capacity under planned grazing in Madiama Commune, Mali (West Africa)
    Badini, Oumar; Stöckle, C. O.; Jones, J.; Bostick, M.; Kodio, Amadou; Keita, Moussa (2004)
    This presentation addresses the problems of overgrazing and degradation of pasture land. Policies that can increase pasture productivity and improve the carrying capacity and soil quality of pastures are assessed using CropSyst simulation modeling. Optimal grazing intensity and intervals (rotational grazing) are evaluated and discussed, based on model analysis from the Madiama commune in Mali (West Africa).
  • A tool for community-based assessment of the implications of development on water security in hillside watersheds
    Luitjen, J.; Knapp, Eric E.; Jones, J. (Elsevier Science Ltd., 2001)
    Increased irrigation, development, and population growth pose a potential threat to water supply in the Cabuyal River watershed in southwest Columbia. The landscape is characterized by steep hillsides with a patchwork of forest, pasture, and a variety of crops such as coffee, cassava, and irrigated vegetables. The International Center for Tropical Agriculture (CIAT) funded a project to develop a GIS-based, watershed-scale simulation model to evaluate a variety of development scenarios with respect to water supply for the year 2025. The authors concluded that there is enough water to support increased demand simulated in each of the development scenarios, but that management practices will determine if sufficient quantity is available at critical times.