土壤中氯苯类化合物的迁移行为

为了污染土壤的恢复 ,应用土壤污染实时模拟系统 ,研究土壤中氯苯类化合物的迁移行为 .结果表明 ,氯苯类化合物主要滞留在土壤相中 ,在气、液 2相中的含量随着其蒸汽压和水溶性的增大而增大 ;15cm以上土壤中的氯苯类化合物由最初的均匀分布 ,变为从上至下浓度逐渐增大的分布 .渗滤液中的氯苯类化合物随渗滤水量变化为 2个阶段 ,渗滤水量 <1000 ml时 ,浓度随水量逐渐下降 ;而渗滤水量 >1000 ml后 ,浓度变化不大 ,趋于某一稳定的浓度值 .氯苯类化合物在土壤层和渗滤水中浓度的变化可较好地用吸附模型来解释 .不同氯苯类化合物的挥发速率随时间延长而降低 ,挥发速率与氯苯施加量的对数和蒸汽压呈良好线性关系 .

Fate and Behavior of Chlorobenzenes in the Soil

In this paper,the fate and behavior of chlorobenzenes(CBs) in the soil was studied by using a real time simulator.The results showed that the CBs mainly retain in the soil phase.The concentration of CBs in the gas and liquid phase increased with the value of vapor pressure and water solubility.The concentration of CBs in the soil profile increased with the depth after leaching process.When the amount of leachate was less than 1 000ml ,the concentration of CBs in leachate increased significantly.When the amount of leachate was large than 1 000ml ,the concentration of CBs in leachate was stable.The behavior of the CBs in the soil and the leachate can be described by a adsorption model,in which the vapor pressure,soil water partitioning coefficient(K_OC)and its solubility in the water can be related to the volatilization.A good correlation between the logarithm concentration of the applied CBs and vapor pressure of the compound was found.