溶解性有机质对土壤中有机污染物环境行为的影响

土壤中溶解性有机质(DOM)是生物活性和物理化学反应活性都很活跃的有机组分，主要通过疏水吸附、分配、氢键、电荷转移、共价键、范德华力等多种作用与有机污染物结合，提高溶液中有机污染物的溶解度，改变土壤中有机污染物的吸附-解吸、迁移-转化等环境行为．DOM对有机污染物的吸附-解吸、迁移-转化过程的影响有双重性：一方面，DOM与有机污染物在土壤表面的共吸附可增加土壤对有机污染物的吸附容量，促进有机污染物在土壤中的吸持；另一方面，DOM对有机污染物的增溶作用，有利于土壤中有机污染物的解吸，提高移动性．作为光敏剂，DOM能提高土壤中有机物的光解反应速率．在一定条件下，DOM也可影响土壤中有机污染物的水解过程．DOM对土壤中有机污染物环境行为的影响与DOM和有机污染物的性质及其相互作用的介质条件密切相关．

Influence of dissolved organic matter (DOM) on environmental behaviors of organic pollutants in soils

Dissolved organic matter (DOM) is an important component of solutions in terrestrial and aquatic ecosystems through its influence on acidity, nutrient availability, and toxicity. DOM could enhance the apparent solubility of organic pollutants and alter adsorption-desorption equilibrium of organic pollutants on soil. The enhancement of organic pollutants desorption in the presence of DOM could facilitate the mobility of organic pollutants in soil. On the other hand, the sorption of DOM by solid sorbents in soil could also enhance the retention of DOM-associated organic pollutants in soil. Furthermore, as a photosensitizer, DOM could promote the photogradation of organic pollutants in soil. And under certain condition, DOM also affected the hydrolysis of organic pollutants in soil solution. The effects of DOM on environmental behaviors of organic pollutants in soils were related to the physico-chemical characteristics of organic pollutants, DOM, and soil.