影响有机污染物在土壤中的迁移、转化行为的因素

FACTORS AFFECTING BEHAVIOR AND FATE OF ORGANIC POLLUTANTS IN SOIL

本文介绍了有机污染物在土壤中的吸附与解吸附、渗滤、挥发和降解等行为过程。探讨了吸附与解吸附机理、土壤有机质含量和类型、水分含量及温度等对此过程的影响。依据某些典型的化合物行为模型，论述了影响土壤中有机污染物渗滤的因素。有机污染物需要先从土壤深层迁移至地表，然后挥发至大气，在土壤中迁移的速率较慢，控制着整个挥发过程，可用Ｆｉｃｋ 第二定律来描述。有机污染物在土壤中的非生物降解主要包括氧化－ 还原、光解和水解等反应。土壤中的Ｏ２ 含量、土壤有机质成分和含量、辐射强度、光谱分布、土壤水分含量、温度和ｐＨ 值等都会影响非生物降解过程。其中有些因素通过影响微生物的生物活性。

Sorption-desorption, leaching, volatilization and degradation of organic pollutants in soil are reviewed in this paper. Mechanisms of sorption-desorption process and impacts of organic matter content, water content and temperature on this process are discussed. Based on some typical models, leaching process and factors influencing this process are described. Before volatilizing into the atmosphere, organic pollutants in soil body have to migrate to soil surface. This migration stage is slow, which controls the rate of the whole volatilization process and can be modeled by the Ficks Second Law. Biotic degradations of organic pollutants in soil mainly include redox, photolysis and hydrolysis, which can be affected by soil oxygen content, type and content of soil organic matters, soil moisture, the intensity and spectral distribution of the solar radiation, temperature and pH value. Through effects on the microbial activity in soil, aerobic and anaerobic conditions of soil, temperature and moisture contents of soil could influence biodegradation of organic pollutants in soil.