水分调控下4种水生植物对重金属的吸附与富集作用

Adsorption and Enrichment Effect of Heavy Metals by Four Aquatic Plants under Water Regulation

[目的]研究水生植物对土壤重金属的吸附与富集能力。[方法]选用美人蕉、黄花鸢尾、旱伞草、再力花4种湿地植物进行盆栽试验,比较其对土壤中4种重金属Cu、Zn、Pb、Cd的富集特性,分析4种水生植物体内重金属的富集与迁移特征,研究4种水生植物地上部分和地下部分重金属的动态分布,评价其对土壤中重金属的综合去除能力。[结果]干湿交替处理不仅降低了植物的迁移系数也改变了重金属的富集能力;干湿交替处理促进了美人蕉、黄花鸢尾、再力花对Cu、Zn、Pb、Cd的富集,抑制了旱伞草对4种重金属的富集;水淹处理4种水生植物对重金属的迁移系数明显高于干湿交替处理。[结论]对于Cu、Zn、Pb、Cd污染的土壤利用美人蕉、黄花鸢尾和再力花进行修复时适合水淹种植,利用旱伞草进行修复时水淹和干湿交替均可。

[Objective]To study the adsorption and enrichment of heavy metals in soil by aquatic plants.[Method]Four wetland plants,Canna indica,Iris wilsonii,Cyperus alternifolius,Thalia dealbata,were selected for pot experiment. The enrichment characteristics of four heavy metals,such as Cu,Zn,Pb and Cd in soil,were compared. The enrichment and migration of heavy metals in four aquatic plants were analyzed. The dynamic distribution of heavy metals in the aerial parts and underground parts of four aquatic plants was studied,and its comprehensive removal of heavy metals in the soil was evaluated. [Result]Dry and wet alternation not only reduced the plant＇s transfer coefficient but also changed the metal＇s ability to enrich. Dry and wet alternation promoted the enrichment of four heavy metals,Cu,Zn,Pb and Cd,and inhibited the enrichment of four heavy metals by Canna indica,Iris wilsonii,Thalia dealbata; The accumulation of Cyperus alternifolius for four heavy metals was inhibited by dry and wet alternation. The migration coefficient of four aquatic plants to the heavy metals in the flooded treatment was significantly higher than that in the dry and wet alternating treatment.[Conclusion]Submerged plants were beneficial to the remediation of Cu,Zn,Pb and Cd contaminated soil for Canna indica,Iris wilsonii and Thalia dealbata. Dry and wet alternate planting and flooding were beneficial to the repair for Cyperus alternifolius.