The sorption of N-heterocyclic compounds on reference and subsurface smectite clay isolates

被引：33

作者：

Zachara, J.M. ^{[1
]}

Ainsworth, C.C. ^{[1
]}

Smith, S.C. ^{[1
]}

机构：

[1] Pacific Northwest Laboratory, Richland, WA 99352, United States

来源：

Journal of Contaminant Hydrology | 1990年 / 6卷 / 03期

关键词：

Carcinogens - Clay - Electrolytes - Solutions - Water Pollution - Underground;

D O I：

10.1016/0169-7722(90)90022-9

中图分类号：

学科分类号：

摘要：

The sorption of the nitrogen heterocycle compounds (NHC) pyridine, quinoline and acridine was measured from Na and Ca electrolyte solutions on specimen montmorillonite (SWyl) and natural smectite clays isolated from subsurface materials. Sorption was dominated by highly selective exchange for the NHC cation with neutral species sorption noted only at high surface concentrations. The selectivity sequence acridine > quinoline > pyridine was observed on all smectites. Na-saturated SWy1 and natural smectites sorbed NHC compounds comparably. Exchange constants on the Na-smectites were fairly constant with surface coverage and correlated with the octanol-water partition coefficients of the NHC and calculated formal charge on specific atom centers in the molecules. In contrast, the exchange of NHC differed between Ca-saturated SWy1 and natural clays. Ca saturation decreased NHC sorption only on SWy1. Exchange constants for the Ca-smectites varied with surface coverage, and the natural Ca-smectites exhibited higher affinity for NHC than Ca-SWy1. Mineralogic differences between the specimen and natural smectites are believed to effect NHC exchange when the smectite clays are aggregated as quasi-crystals in Ca suspensions. Organic material and Fe-oxides associated with natural smectites have no observable effect on NHC adsorption.

引用

页码：281 / 305