Simultaneous Application of Dissolution/Precipitation and Surface Complexation/Surface Precipitation Modeling to Contaminant Leaching

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• 作者：Defne S. Apul ; Kevin H. Gardner ; T. Taylor Eighmy ; Ann-Marie Fä ; llman ; and Rob N. J. Comans
• 刊名：Environmental Science & Technology
• 出版年：2005
• 出版时间：August 1, 2005
• 年：2005
• 卷：39
• 期：15
• 页码：5736 - 5741
• 全文大小：156K
• 年卷期：v.39,no.15(August 1, 2005)
• ISSN：1520-5851

文摘

This paper discusses the modeling of anion and cationleaching from complex matrixes such as weathered steelslag. The novelty of the method is its simultaneousapplication of the theoretical models for solubility, competitivesorption, and surface precipitation phenomena to acomplex system. Selective chemical extractions, pHdependent leaching experiments, and geochemical modelingwere used to investigate the thermodynamic equilibriumof 12 ions (As, Ca, Cr, Ba, SO₄, Mg, Cd, Cu, Mo, Pb, V, andZn) with aqueous complexes, soluble solids, and sorptivesurfaces in the presence of 12 background analytes (Al, Cl,Co, Fe, K, Mn, Na, Ni, Hg, NO₃, CO₃, and Ba). Modelingresults show that surface complexation and surfaceprecipitation reactions limit the aqueous concentrationsof Cd, Zn, and Pb in an environment where Ca, Mg, Si, andCO₃ dissolve from soluble solids and compete for sorptionsites. The leaching of SO₄, Cr, As, Si, Ca, and Mg appearsto be controlled by corresponding soluble solids.