J. curcas and Manihot esculenta are potential super plants for phytoremediation in multi-contaminated mine spoils

Abstract

Phytoremediation approaches have increasingly been applied in environmental remediation projects. In this study, the potentials of Manihot esculenta (M. esculenta), Vigna unguiculata (V. unguiculata) and J. curcas curcas (J. curcas) in remediating multi-contaminated mine spoils was evaluated. The target potentially toxic elements (PTEs) are Cd, As, Zn, Pb, and Hg. The test plants were grown and monitored under growth stress conditions for 270 days. Using inductively Coupled Plasma- Mass Spectrometry and EPA method 200.8, the total elemental contents in the shoot and root parts of the plants were determined. Significant differences (p< 0.01) were observed in the uptake performance of the test plants. For example, M. esculenta and J. curcas, bioaccumulated 50- 80 % of the various baseline PTE contents in their root parts at 270 days after planting. In contrast, < 27 % of PTEs were found in the root parts of V. unguiculata, except Zn at 70 %. Growth stressors and soil PTEs were factors that reduced biomass production in respective plants by 25 %. Cummulatively, the performance order M. esculenta> J. curcas> V. unguiculata was observed for multi-contaminant removal in soils. Techniques for enhancing the easy cultivation of the test plants are recommended to enhance their applicabilities in phytoremediation projects.