A novel method for determining the adequate dose of a chelating agent for phytoremediation of radionulides contaminated soils by M. cordata

A chelating agent in an adequate dose used to enhance phytoremediation of radionuclide-contaminated soil should not inhibit the growth of the plant. If this constraint condition is satisfied, the total bioaccumulation amount (TBA) of radionuclide by the plant can be maximized. This is a constrained optimization problem to determine the adequate dose of the chelating agent for phytoremediation of radionuclide-contaminated soil. In this research, an adequate dose of a chelating agent for phytoremediation of radionuclide-contaminated soil was determined by a novel approach using pot experiments. The proposed approach was applied to specify the adequate doses of citric acid (CA) and S,S-ethylenediamine disuccinic acid (EDDS) for phytoremediation of uranium contaminated soil by M. Cordata. By using this method, the adequate doses of CA and EDDS for phytoremediation of 238U, 232Th and 226Ra contaminated soils by M. cordata were measures as 10.0 and 5.0 mmol kg−1, respectively. The results showed that the approach could be used to establish the adequate dose of a chelating agent for phytoremediation of radionuclide or other toxic heavy metal contaminated soil by a plant.