Metal cation/anion adsorption on calcium carbonate [electronic resource] : Implications to metal ion concentrations in groundwater
- Washington, D.C : United States. Dept. of Energy. Office of Energy Research, 1990. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: (55 pages) : digital, PDF file
- Additional Creators:
- Pacific Northwest Laboratory, United States. Department of Energy. Office of Energy Research, Electric Power Research Institute, and United States. Department of Energy. Office of Scientific and Technical Information
- This chapter evaluates the sorption behavior of metallic ions on specimen calcite as a basis for determining the importance of calcite relative to other subsurface sorbents, such as layer silicates and oxides, in controlling metal ion concentration in calcareous groundwaters. A review of the literature shows the sorption of both metallic cations and anions on calcite over ranges in pH and CO₂ partial pressure to be consistent with a surface-exchange process where cations exchange with surface Ca and anions exchange with surface CO₃. A general surface-exchange model was developed to account for the effects of Ca and CO₃ concentrations, pH, and calcite surface area on cation and anion sorption onto calcite. The model was applied to recently developed experimental sorption data of Zn and SeO₃ on specimen calcite in equilibrium CaCO₃(aq) suspensions. The surface-exchange model was able to describe the effects of pH on both cation and anion sorption, and provided good predictions of the effects of variable CO₂(g) pressure on Zn sorption and of PO₄ on SeO₃ sorption. The surface-exchange model, combined with sorption constants for other phases, was used to calculate Cd sorption to a hypothetical aquifer material containing a mixture of sorbents. The sorbent concentrations were fixed to those expected in groundwater zones. The multi-sorbent calculation documented the importance of calcite as a sorbent for metallic ions in groundwater.93 refs., 18 figs., 5 tabs.
- Published through SciTech Connect., 05/01/1990., "pnl-sa-18360", " conf-8905356--1", "DE91005611", ": RP2485-03", Environmental Protection Agency (EPA) workshop on metal speciation and transport in groundwaters, Jekyll Island, GA (USA), 24-26 May 1989., and Resch, C.T.; Zachara, J.M.; Cowan, C.E.
- Funding Information:
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