Record Display for the EPA National Library Catalog


Main Title Chemical Speciation and Competitive Cationic Partitioning on a Sandy Aquifer Material.
Author Loux, N. T. ; Brown, D. S. ; Chafin, C. R. ; Allison, J. D. ; Hassan, S. M. ;
CORP Author Environmental Research Lab., Athens, GA. ;Technology Applications, Inc., Athens, GA. ;Computer Sciences Corp., Athens, GA. ;Mansoura Univ. (Egypt).
Publisher c1989
Year Published 1989
Report Number EPA/600/J-89/292;
Stock Number PB90-198128
Additional Subjects Aquifers ; Cations ; Diffusion ; pH ; Metals ; Graphs(Charts) ; Tables(Data) ; Ground water ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB90-198128 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 17p
Coupled geochemical speciation/transport models are being developed to assess potential transport of metal contaminants in the subsurface environment. In a test of the geochemical speciation portion of the effort, MINTEQA2 model predictions are compared with laboratory data concerning the pH dependent partitioning behavior of eight cationic contaminants (Ba, Be, Cd, Cu, Ni, Pb, Tl, and Zn) on a sandy aquifer material in an oxidized environment. MINTEQA2 contains provisions for describing potential attenuation due to both mineral phase precipitation processes and adsorption processes resulting from amorphous iron oxides in aquifer materials (MIT Diffuse Layer Model). In the comparison, several trends were discerned. (1) Adsorptive processes tend to better describe the pH-dependent partitioning behavior of transition metals (especially Pb, Zn, and Ni). (2) Cd behavior is better described by precipitation as a cadmium carbonate phase. (3) Cu behavior is not reasonably described by the model. (4) Ba and Be comparisons are poor (although presumably their partitioning behavior results from adsorptive and/or pH sensitive solid solution processes). (5) Unlike the other elements, the behavior of Tl is relatively insensitive to pH.