A Primary Study on Assessment of Phytoremediation Potential of Biofuel Crops in Heavy Metal Contaminated Soil

Phytoremediation is a low cost and eco-friendly emerging technology for treatment of contaminated soils with the use of green plants. In this study, the accumulation potential to heavy metals by two biofuel crops (maize and sunflower) and two metal accumulator plants (Elsholtzia splendens (ES), Tagetes patula L. (TP)) was studied with pot culture filled with a heavy metal contaminated soil, in order to compare their suitability for phytoremediation of contaminated soils. Sunflower showed the highest accumulation level for Cu (150 ug/pot) and Zn (10893 ug/pot) in the shoot part compared to other three plants. Maize showed a similar accumulation level for Cu (104 ug/pot) and Zn (7454 ug/pot) to TP, but a much higher level than ES. TP showed noticeable accumulation levels for Pb (196 ug/pot) and Cd (637 ug/pot). ES generally had the lowest accumulation capacity for Cu (38.5 ug/pot), Zn (2784 ug/pot), Pb (35.4 ug/pot) and Cd (18.2 ug/pot). Therefore, the two biofuel plants had higher or similar phytoremediation potential of heavy metals compared to the two accumulator plants. This study provided useful data for considering biofuel plants as potential economic crops for phytoremediation.