土壤有机质对疏水性有机污染物的非线性吸附及其影响因素

土壤有机质(SOM)是土壤的重要组成部分,它对疏水性有机污染物(HOCs)的吸附作用对污染物在环境中的迁移转化有着至关重要的影响。近年来的一些研究表明,HOCs在SOM上的吸附行为并不严格地符合传统的线性分配模型。本文综述了近年来一些学者提出的SOM对HOCs的非线性吸附作用的机制及其影响因素,认为SOM的组成和结构均对HOCs的吸附有着重要的影响。SOM吸附在土壤矿物表面后,其结构或各组分的比例发生了改变,从而对其本身的吸附作用产生影响。溶液的化学环境(主要是阳离子)会对SOM的结构和吸附作用产生影响,特别是当溶液中存在一些过渡金属(如,铜或银)的离子时,共吸附的金属离子可能会与多环芳烃类分子形成阳离子-π键的作用,从而促进多环芳烃类物质在SOM上的吸附。

Nonlinear sorption of hydrophobic organic contaminants on soil organic matter

Soil organic matters(SOM) are the crucial constituents of soil.The sorption of hydrophobic organic contaminants(HOCs) on SOM has great impact on the migration and transformation of HOCs in environment.Recent studies indicated that the sorption of HOCs on SOM was not fitted strictly with the linear partition model.This paper reviewed some proposed mechanisms on nonlinear sorption and the influence factors that affected the HOCs sorption by SOM.It is concluded that both the constituents and structure of SOM have strong influence on HOCs sorption.The adsorption of SOM on minerals changed the structure or the proportion of components in SOM,which affected the sorption.The change of the solution environment could affect the adsorption mainly through the cation effect on the structure and configuration of SOM.Specially,co-adsorption of some transition metals(e.g.,Cu2+ or Ag+) might increase the sorption of polycyclic aromatic hydrocarbons(PAHs) on SOM by forming cation-π interactions between cations and aromatic rings.