Chelator effects on bioconcentration and translocation of cadmium by hyperaccumulators, Tagetes patula and Impatiens walleriana

French marigold (Tagetes patula) and impatiens (Impatiens walleriana) can act as hyperaccumulator plants for removal of cadmium (Cd) from contaminated sites. In this study, an exponential decay model was used to predict the maximum removal of Cd from artificially spiked soils by impatiens. Application of a chelator, EDTA, was also assessed for effects on the bioconcentration (BCF) and translocation (TF) factors of the two species with four replicates. Exposure to Cd significantly decreased the biomass of two plant species. Impatiens and French marigold accumulated Cd at a rate of 200–1200 mg Cd kg−1 in shoots, with BCFs and TFs of 8.5−15 and 1.7−2.6, respectively.

► We used an exponential decay model to predict the maximum removal of Cd from impatiens.
► Impatiens was able to accumulate 10-fold higher concentration of Cd in the shoot than a typical hyperaccumulator.
► The bioconcentration factor and translocation factor of impatiens were greater than unity.
► Planting impatiens naturally is a better practice to phytoextraction of Cd-contaminated soil.