【摘要】 为揭示在溶解性有机物(DOM)作用下土壤中重金属的吸附和迁移规律并确定迁移数学模型,通过不同条件下的等温吸附实验和土柱淋滤实验,研究了溶解性有机物对重金属Cu,Cd,Pb,Zn在褐土中吸附和迁移行为的影响。结果表明DOM对Cu和Cd在土壤中的吸附促进作用较明显,对Pb有微弱的促进作用,对Zn的吸附影响不明显;随着pH的改变,25℃下Cu在土壤中的吸附高于15℃和35℃条件下。DOM质量浓度越高,Cd、Zn溶出的促进效果越明显,Cu、Pb则恰好相反。DOM对土壤中Cd、Zn的垂直迁移起着促进作用,而对Cu、Pb迁移起着一定的抑制作用;DOM对土壤重金属的平均迁移量随时间的延长而减少。此迁移模型能够定量计算并预测重金属质量浓度的时空分布。更多还原

【Abstract】 To reveal the adsorption and migration rule of heavy metals in the soil under the effect of Dissolved Organic Matter(DOM) and to determine the migration mathematical model,we researched the effect of Dissolved Organic Matter(DOM) on adsorption and migration of Cu,Cd,Pb and Zn in cinnamon soils by the isothermal adsorption experiment and the soil column leaching experiment under different conditions.The results indicate: it is obvious that the DOM plays a stimulative effect in the adsorption of Cu and Cd in the soil and it has a little catalytic effect on the adsorption of Pb while the effect on the adsorption of Zn is not obvious;with the changing of pH,the adsorption amount of Cu at 25 ℃ is higher than the amount at 15 ℃ and 35 ℃.The higher the mass concentration of DOM,the more obvious the promotive effects on the dissolution of Cd and Zn,which is contrary to Cu and Pb.DOM plays a catalytic effect on the vertical migration of Cd and Zn,while it plays a certain inhibitory effect on the migration of Cu and Pb.The average migratory amount of DOM on the heavy metals in the soil decreases with the extension of time.This migration model can give quantitative calculation and predict the temporal and spatial distribution of mass concentration of heavy metals.更多还原