Effect of NTA and EDTA on Arsenic Uptake from Contaminated Soil by Mimosa Pudica

The purposes of this study were to determine arsenic accumulation in the root, stem and leaves of Mimosa Pudica L. and compare the efficiency of two chelating agents, in enhancing arsenic uptake by the plant. This study also investigated the distribution of arsenic in the plant. The results showed that arsenic accumulation in root was significantly higher than in stem and leaves (P£0.05). The maximum arsenic accumulated in roots, stem and leaves were 29.71 and 6.32 mg arsenic/kg plant, after 120 days, respectively. The average arsenic accumulation in all parts of the plant over four months was in the range of 2.71 - 36.03 mg arsenic /kg plant and set ethylenediaminetetraacetic acid 100 mg/kg soil showed the highest arsenic accumulation in Mimosa Pudica L. Overall, with the same harvesting times and application doses of chelating agents, ethylenediaminetetraacetic acid has a greater efficiency for enhancing arsenic uptake in this plant than nitrilotriacetic acid. Moreover, the synchrotron µ-X-ray fluorescence spectroscopy (Beamline 6b) analysis provided an unexpected result on the distribution of arsenic in the plant caused by the limitation of the radiation beam line. However, this research did not study the chemical reactions between arsenic and the chelating agents. Therefore, for future studies it is recommended that more detail at molecular level be investigated and more study be done on the influence between the applications of fertilizers and without fertilizers which might help us to clarify the factors that stimulate the movement of arsenic from the soil up to the plants.