土壤改良介质对矿区先锋植物富集重金属能力的影响

为了探讨土壤改良介质对矿区先锋植物富集重金属能力的影响,选取郴州市柿竹园尾砂坝、高斯贝尔尾砂坝两处矿区土壤,采用沸石、40%沸石+60%草炭、80%沸石+20%食用菌下脚料3种介质以1∶15混合尾砂坝土壤形成改良土壤;利用改良土壤对多种先锋植物(小飞蓬、花叶水葱、苦菜)盆栽培育4个月,然后测定植物根、茎叶以及改良土壤中Cu、Zn、Pb的含量。结果表明,两处尾砂坝土壤中重金属含量关系为Zn>Pb>Cu,其中高斯贝尔尾砂坝土壤的Cu、Pb含量更高。柿竹园尾砂坝土壤中Zn含量约为Cu含量的6~25倍、Pb含量的3~10倍,而高斯贝尔尾砂坝中Zn含量约为Cu含量的6~8倍、Pb含量的1~3倍。土壤改良介质对植物富集Cu、Zn、Pb的能力均有影响,对于不同重金属污染的土壤,可采取多种植物混合种植,实现重金属污染土壤的修复。

Effects of Modified Soil Media on Heavy Metal Accumulation Ability of Pioneer Plants in Mining Areas

In order to investigate effects of modified soil media on heavy metal accumulation ability of pioneer plants in mining areas, soils from Shizhuyuan sand tailings  dam and Gospell sand tailings dam in Chenzhou City were selected for test. Three kinds of media, including zeolite, 40% zeolite+60% peat, 80% zeolite+20% edible fungus scrap, were mixed with the soil at the ratio of 1∶15 to prepare modified soil, which was then used to cultivate several kinds of potted pioneer plants. After 4 months, contents of Cu, Zn and Pb in plant roots, stems and leaves and modified soil were measured. Results showed that heavy metal contents in the soil of two tailings dams presented to be in the following order: Zn>Pb>Cu, and contents of Cu and Pb in Gospell sand tailings dam was higher. In the Shizhuyuan sand tailings dam, Zn content in the soil was 6~25 times of Cu content and 3~10 times of Pb content therein. While in Gospell sand tailings dam, Zn content in the soil was 6~8 times of Cu content and 1~3 times of Pb content therein. It is found that the modified soil media brought impact on the Cu, Zn and Pb accumulation ability of plants. Several kinds of plants cultivated together with different kinds of modified soil can be benefit for the restoration of soil contaminated by different heavy metals.