Study on Tolerance and Accumulation Potential of Biofuel Crops for Phytoremediation of Heavy Metals

Abstract

Phytoremediation is a cost-effective and environment-friendly technology that uses plants for environmental remediation. In order to promote practical application of phytoremediation, an income generation phytoremediation strategy was suggested using biofuel crops for utilization and phytoremediation of contaminated soils. In this study, the tolerance and accumulation potential to heavy metals of two biofuel plants and two accumulator plants were investigated in order to evaluate their suitability for phytoremediation. Two biofuel crops, maize (Zea mays L.) and sunflower (Helianthus annuus L.), and two accumulator plants, Elsholtzia splendens (ES) and Kummerowia striata (KS) were exposed to the hydroponic mixtures of Pb, Cu and Cd. Results showed that, at the 0.01 mol/L application level of Pb, Cu and Cd, sunflower had the highest accumulation ability for Pb, Cu and Cd in the shoot part compared to other three plants, and maize had a similar accumulation level to ES and KS. Sunflower also had much higher shoot/root ratios of accumulation for Cu and Cd than maize. However, sunflower showed lower tolerance to Pb, Cu and Cd contamination than maize, ES and KS. This study provided useful data supporting the use of biofuel plants in phytoremediation.