超量积累植物对污染土壤重金属的吸收和活化机理

In the present study, uptake, transport and solubility of Zn and P in hyperaccumulator T. caerulescens and non-hyperaccumulator T. ochroleucum were compared. The majority of Zn in shoots of hyperaccumulator T. caerulescens is present in water soluble forms. The shoots of T. caerulescens had significantly higher concentrations of total and water-soluble Zn and lower concentrations of total and water-soluble P than those of T. ochroleucum. The results showed that Zn hyperaccumulation in is accompanied by the ability to maintain the essential nutrients within adequate for optimum growth. T. caerulescens has potential for removing Zn from moderately to highly contaminated soils. Lead phytoextraction from contaminated soil with high-biomass plant species was studied also. Lead concentration in the cabbage shoots reached 5010 mg/kg dry matter on day 7 after EDTA application. Application of EDTA in three separate dose was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one- and two-dose application methods. This approach could help to minimize the amount of chelate applied in the field and to reduce the potential risk of soluble Pb movement into ground water.

利用超量积累植物治理重金属污染土壤是国际上新提出的一条探索途径。本课题发遏蓝菜属植物为材料，研究该植物重属吸收与土壤重金属形态火之间的关系，根际土壤的重金属形态转化、浓度变化和迁移规律，分离和超量积累植物活化土壤重金属的根系分泌物，阐明超量积累植物活化大重金属的机理，为开发这种植物资源和重金属污染土壤的治理提供科学依据。.