The role of DTPA and EDDS in remediation of Se from contaminated soil by Brussels sprouts (Brassica oleracea var. gemmifera)

摘要

The use of plants to remove heavy metals from soil (phytoremediation) is emerging as a cost-effective way compared conventional methods. Because contaminants such as Se, Pb and Cd have limited bioavailability in the soil, methods to facilitate their transport to the stems and roots of plants are required for successful phytoremediation. The objective of this study was to investigate the effects of adding different rates of DTPA (0, 0.5, 1 and 5 mmol/kg of diethylene triamine penta acetate), and EDDS(0, 5, 7.5, and 10 mmol/kg of ethylene daimine dissuccinate) on Se availability in contaminated soils with 0, 5, 10 and 15 mg/kg NaSeO_4, on the capacity of Brussels sprouts plants to take up Se under a greenhouse conditions. Results indicated that DTPAand EDDS application to Se contaminated soils significantly decreased dry matter yield of plants. Most plant available fractions (water soluble and exchangeable), carbonate, metal oxide, organic matter bound fraction increased linearly with Se application with regression R~2 values of 0.90 or greater. At all DTPA and EDDS application rates, Se concentrations in leaves were about 2-3 times higher than in roots and about 3-4 times higher than in stems. Application of DTPA and EDDS over 0.5 and 7.5 mmol/kgdoses significantly decreased total Se uptake in leaves, stems, and roots in plants.