Modeling Sorption of Trace Metals on Natural Sediments by Surface Complexation Model

详细信息    查看全文

• 作者：Feiyue Wang and ; Jingsheng Chen ; and Willis Forsling
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：February 1997
• 年：1997
• 卷：31
• 期：2
• 页码：448 - 453
• 全文大小：228K
• 年卷期：v.31,no.2(February 1997)
• ISSN：1520-5851

文摘

The potential possibility of the surface complexationmodelsto describe the sorption of trace metals on naturalsediments has been suggested since the late 1980s, whichshould be of natural importance to predict thebioavailabilityof trace metals in aquatic sediments. This possibilitywastested based on 11 geographically and hydrologicallydiverse natural aquatic sediment samples. Thesorptionof Cu(II), Zn(II), Pb(II), and Cd(II) on thesesediments wasstudied by both sorption isotherm and pH-edge sorptionexperiments. The experimental sorption data were fitwellby the surface complexation model (the double-layermodel).The linear free energy relationship (LFER) between thesurfacecomplexation constants (K_s) of trace metals onthe sedimentsand the corresponding first-hydrolysis constants(*K₁) wasobserved, which could be expressed as log K_s =a log*K₁ + b. The slope of thelinear regression, a, was dependenton the sediment composition: a = 0.19TOC -0.09Oxides+ 1.31 (n = 11), where TOC (%) is the totalorganiccarbon and Oxides (%) include reactive iron oxide,amorphousiron oxide, cryptocrystalline manganese oxide, andaluminum oxide. The results strongly suggest that thesorptionof trace metals on natural sediments could be describedreasonably by the surface complexation model andpredicted potentially from the relationships betweenK_sand *K₁ and the sedimentcomposition.