Adsorption kinetics of pentachloroethane by iron-bearing smectites

被引：27

作者：

Cervini-Silva, J ^{[1
]}

Wu, J ^{[1
]}

Stucki, JW ^{[1
]}

Larson, RA ^{[1
]}

机构：

[1] Univ Illinois, Dept Nat Resources & Environm Sci, Urbana, IL 61801 USA

来源：

CLAYS AND CLAY MINERALS | 2000年 / 48卷 / 01期

关键词：

CMS clay SWa-1; CMS clay NG-1; dehydrochlorination; iron(II); iron(III); montmorillonite; nontronite; oxidation; pentachloroethane; reduction reactions; tetrachloroethene;

D O I：

10.1346/CCMN.2000.0480116

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The oxidation state of structural Fe greatly alters surface chemistry, which may have a large influence on clay-organic interactions. The effect of structural-iron oxidation state on chlorinated hydrocarbons at the clay-water interface was examined. Pentachloroethane (5CA) was reacted with oxidized, reduced, and reoxidized forms of three different smectites: montmorillonite, ferruginous smectite, and nontronite in aqueous suspension under controlled-atmosphere conditions. Pentachloroethane was found to adsorb at different rates for the three smectites. A series of 5CA-adsorption rate constants in the presence of these clays showed a strong correlation with the Fe(II) content of the clay (r2 = 0.98). The clay surface behaves as a Brønsted base and promotes 5CA dehydrochlorination. The adsorption kinetics at the clay-water interface were described by the formation of a precursor complex prior to 5CA dehydrochlorination.

引用

页码：132 / 138

页数：7

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