Modeling brackish solution influences on the chemical and physical behavior of temperate region soils
1993
Marsi, M. | Evangelou, V.P.
Oil well brine discharges on to soils of mixed mineralogy, commonly found in the eastern U.S., have become an environmental issue. Because of this, there is need to understand sodicity of soils that have developed under a temperate climate. In this study, two Kentucky soils of mixed mineralogy (Pembroke; fine-silty, mixed, mesic, Mollic Paleudalf and Uniontown; fine-silty, mixed mesic, Typic Hapludalf) were chosen for modeling purposes to evaluate the influence of ionic strength (I), sodium adsorption ratio (SAR) and pH on the Vanselow exchange coefficient (K(V)), and dispersion/saturated hydraulic conductivity relationships. The results showed that both soils exhibited at least two classes of exchange sites but the Na+-Ca2+ exchange behavior of the Pembroke soil was relatively independent of pH and ionic strength. Soil dispersion was shown to increase as electrolyte concentration was decreased and sodium adsorption ratio (SAR) and pH were increased. Furthermore, dispersion of the Uniontown soil was more dependent on electrolyte concentration, and SAR changes, but less dependent on pH changes than that of the Pembroke soil. The soil components shown to regulate saturated hydraulic conductivity were: 1) clay dispersion and 2) clay swelling. The first mechanism was associated with Pembroke, a soil with relative low expansion potential, while the second mechanism was associated with Uniontown, a soil with relative high expansion potential.
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