Systematic Study of Metal Ion Sorption on Selected Geologic Media. Annual Report, October 1978-December 1979

摘要

This report summarizes results of the past fifteen months of research in the programs Selection of Multiple Tracers for Enhanced Oil Recovery Systems and that portion of Ion Exchange Characteristics of Enhanced Oil Recovery Systems concerned with alkaline earth ion-alkali ion equilibria on clay minerals. Because of funding reductions, we have suspended further activity in these areas except for a small amount of research necessary to complete a few topics. This report therefore represents essentially a final report on these adsorption studies. An extensive study was completed of the distribution of Na(I) and Ca(II) ions between a common clay, montmorillonite, as well as several other clays, and a series of solutions of constant total ionic strength (I) with varying ionic strength fraction of sodium. Distribution coefficients for Sr(II) were determined for a variety of conditions on various clay minerals and oxides. In general for clay minerals, the values of D/sub Sr/ decrease sharply with salinity and except for kaolinite are fairly independent of pH. For adsorption of Sr(II) on oxides, values of D tend to depend only slightly on salinity but increase sharply with pH. For I exp - adsorption on a large number of rocks and minerals, with few exceptions low values of D are found. Distribution coefficients have also been measured for Ni(II), Zn(II), Co(II), and Cd(II). For adsorption of these ions on montmorillonite, it was found that distribution coefficients were highly dependent on both pH and loading. For Cd(II) in solutions of high chloride concentration where Cd(II) forms chloride complexes, the values of D are lower than in non-complexing media. These adsorption studies serve to define conditions under which these ions may or may not serve as good tracers. (ERA citation 05:032782)