Enhancement of cadmium phytoextraction from contaminated soils with Artemisia princeps var. orientalis

Phytoextraction using plants to remove toxic metals from the environment is an emerging technology for contaminated land remediation. The maximum efficiency of phytoextraction is controlled by the availability of metals in the soil. Plant availability of soil metals are often manipulated by additions of chelating agents. We conducted a greenhouse experiment to evaluate the effects of chelator and ligands on phytoextraction of Cd from contaminated soils with an endemic plant, Artemisia princeps var. orientalis. Cadmium content in the plant was highest in (NH₄)₂SO₄ treatment, but sulfur powder had little effect on Cd accumulation in the plant due to low buffering capacity of the soil and slow turnover rate of S^o to SO₄^2-. Cadmium content in the plant was slightly increased in oxalic acid and EDTA treatments by accompanying pH decrease in the soil. Phytoremediation Index (PI) increased in the order of control<sulfur powder (S^o)<oxalic acid<(NH₄)₂ SO₄< EDTA treatments. In addition, Cd content in the plant showed the same trend with PI except for EDTA treatment. It could be postulated that EDTA addition should be avoided for the soil with high Cd availability as it might accelerate a continuous leaching of Cd-EDTA complexes from surface to subsoil during the phytoextraction. Overall results indicated that (NH₄)₂SO₄ can be used to enhance Cd accumulation in the Artemisia princeps var. orientalis during phytoextraction.