Chelate-assisted Pb phytoextraction: Pb availability, uptake, and translocation constraints

Journal Article · Tue Jun 01 04:00:00 EDT 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es9809253· OSTI ID:355546

Wu, J; Hsu, F C; Cunningham, S D ^[1]

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1. Central Research and Development, Newark, DE (United States)

Chelates have been shown to enhance phytoextraction of Pb from contaminated soil. Mechanisms behind this phenomenon, however, remain largely unexplored. In this paper the authors examine chelate effect on Pb dissolution, plant Pb uptake, and internal plant Pb translocation. EDTA was found to be the most efficient in increasing water-soluble Pb concentration in the test soil. Unfortunately, Pb-EDTA is highly water-soluble and posses potential risks to ground water in its application. In addition, it would not appear to be ideally suited for plant uptake and translocation based upon the relative water solubility of Pb-EDTA. The authors demonstrated that N,N{prime}-di(2-hydroxybenzyl)ethylenediamine N,N{prime}-diacetic acid (HBED) resulted in Zea mays root Pb content significantly higher than did EDTA, indicating that a chelate better than EDTA might be designed. Fortuitously, EDTA appears to increase overall plant transpiration, the driving force in phytoextraction of the Pb-chelate complex from soil. The authors also found that there was a significant increase in Pb uptake and translocation for corn transplanted into soil, then treated with EDTA, as compared to plants germinated and grown in Pb-contaminated soil to which EDTA was subsequently applied. These results demonstrate that significant improvement over current chelate-assisted phytoextraction of Pb may be possible.

• OSTI ID: 355546
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 11 Vol. 33; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BIODEGRADATION
EDTA
LEAD
PLANTS
REMEDIAL ACTION
ROOT ABSORPTION
SOILS
TRANSLOCATION