Bioaccumulation of Cadmium in Siam (Chromolaena odorata) and Node (Synedrella nodiflora) Weeds: Impact of Ethylene Diamine Tetraacetic Acid (EDTA) on Uptake

The translocation and accumulation of Cd by Synedrella nodiflora and Chromolaena odorata plants growing in artificially Cd-contaminated soils amended with EDTA or without amendment had been studied to assess the phytoremediation potential of both species. Results showed that roots of S. nodiflora had the capacity of taking up a maximum 86.2 mg/kg of Cd from the contaminated soil while concentration in shoots amounts to a maximum 73.8 mg/kg. C. odorata was able to accumulate 42.8 mg/kg and 33.8 mg/kg in its roots and shoots respectively. The mobility of soil cadmium and the concentration of Cd in plants were both increased by EDTA amendment. EDTA application facilitated the translocation of Cd since the concentration in the roots and shoots of S. nodiflora increased to 104.9 mg Cd/kg and 77.0 mg Cd/kg respectively although the amendment effect was more pronounced on C. odorata increasing from 42.8 mg Cd/kg in roots from non-amended soils to 83.7 mg Cd/kg in the roots from amended soils. Despite the improved uptake by C. odorata, S. nodiflora appears to be more suitable for phytoremediation of Cd contaminated soils.