Cd、Zn在水体-土壤-双穗雀稗间的迁移模拟研究

Simulation of Cd^(2+) and Zn^(2+) Migration among Water,Soil and Paspalum Distichum

以模拟江水-双穗雀稗-土壤构成的有机体系为研究对象,通过动态模拟实验,研究了外源重金属Cd2+、Zn2+单一及复合处理时对双穗雀稗生长及外源重金属在水体、土壤和双穗雀稗中的迁移富集情况。结果表明:较低浓度的水体Cd、Zn对双穗雀稗生长几乎没影响,高浓度时对其生长有抑制作用。双穗雀稗主要通过根、茎富集重金属离子,随着处理浓度的增加迁移富集量逐渐增大,迁移富集量地下部>>地上部,Cd、Zn在双穗雀稗中的迁移表现出协同效应,而在土壤中Cd对Zn的迁移富集存在拮抗作用,Zn对Cd的迁移富集存在协同作用。双穗雀稗可明显降低水体中外源重金属Cd、Zn的含量,是三峡库区消落带植被重建、修复重金属(Cd、Zn)污染的优良物种之一。

A dynamic simulation experiment was conducted with organic systems involving river-water of the Yangtze, Paspalum distichum and soil to study the effects of heavy metal Cd2＋, Zn2＋ enrichment and migration. The results of the etpedrnent showod that lower water levels of Cd2＋, Zn2＋ had almost no effect on the growth of Paspalum distichum, but the high conc0ntration can be inhibit its growth. Paspalum distichum enriched heavy metal ions mainly through roots and stems, and with the increases of ions concentration, migration and enrichment quantities increased as well; migration of Cd2＋, Zn2＋ in Paspalum distichum exhibited synergistic effects, while as to the migration in the soil, Cd2＋ ion had some antagonism towards Zn2＋ ions accumulation, but in contrary, presence of Zn2＋ ion exhibited some synergistic effects on concentration of Cd2＋ ions, Paspalum distichum was of the ability to decrease exogenous heavy metal content in water bodies such as Cd2＋ and Zn2＋, so it could be used as one of fine species in remediation of heavy metal pollution in the drawdown areas in the Three Gorges Reservoir.