Simultaneous Hyperaccumulation of Multiple Heavy Metals by Helianthus Annuus Grown in a Contaminated Sandy-Loam Soil

Abstract

Phytoremediation is a promising means for the treatment of contamination arising from heavy metal spills. Although several species have been identified as hyperaccumulators, most of the studies were performed with only one heavy metal. Experiments were conducted with two cultivars of H. annuus exposed to different combinations of metal contamination (30 mg/kg Cd, Cr, Ni, As, and/or Fe). Cultivar efficiency was based on total metal uptake, as well as translocation and selectivity of each metal. The results for each cultivar were also compared after 0.1 g/kg or 0.3 g/kg EDTA was added to enhance metal bioavailability. The key finding was that H. annuus achieved hyperaccumulator status for multiple metals simultaneously: Cd, Cr, and As.

KEYWORDS:

• Helianthus annuus
• hyperaccumulator
• phytoremediation
• metals
• sunflowers

ACKNOWLEDGMENTS

The project was funded by the Ohio Plant Biotechnology Consortium. The authors would like to thank Dr. Randall Mitchell, Biology Department at The University of Akron. These experiments would not have been possible without his generous use of his greenhouse space.