A geochemical study of toxic metal translocation in an urban brownfield wetland

Rhizosphere soil and dominant plant samples were collected at a brownfield site in New Jersey, USA, during summer 2005 to evaluate plant metal uptake from the contaminated soils. Metal concentrations varied from 4.25 to 978 μg g−1 for As, 9.68–209 μg g−1 for Cr, 23.9–1870 μg g−1 for Cu, and 24.8–6502 μg g−1 for Zn. A wide range of metal uptake efficiencies in the roots, stems and leaves was found in this study. Data showed that (1) Betula populifolia has high Zn, Cu and As accumulations in the root, and high concentrations of Cu and Zn in the stem and the leaf; (2) Rhus copallinum has high accumulation of Zn and Cr in the leaf and Cu in the stem; (3) Polygonum cuspidatum has high accumulations of Cu and As in the root; and (4) Artemisia vulgaris shows high Cu accumulation in the leaf and the stem.

► Rhizosphere soil and dominant plant samples were studied at a brownfield.
► Plant roots showed exceptional capacity of heavy metal accumulation.
► Metal uptake efficiency decrease with the increases of pH and organic matter.
► Variations in metal uptake efficiency in the root, stem and leave were found.