Optimization of chelator-assisted phytoextraction, using EDTA, lead and Sedum alfredii Hance as a model system

Pot and leaching column experiments were conducted to optimize chelator-assisted phytoextraction of lead (Pb) from contaminated soils. Optimum phytoextraction occurred at added EDTA concentration of 5 mM in single dose for 10 days in low Pb soil (treated with 400 mg kg(-1) soil), while it would be better for high Pb soil (treated with 1,200 mg kg(-1) soil) with five intermittent doses of 10 mM EDTA for 7 days. Combined with column experiment, it could be inferred that chelator-assisted phytoextraction is more suitable for the slightly contaminated soils.