HA2 Phytoremediation
Ballroom F, Level 4
8:00 AM - 12:00 PM, Thursday, 13 November 2003
Chair: Baladi, Sadika ,
(489) Mesquite: a Desert Plant Potentially Usable to Phytoremediate Chromium Contaminated Soil.
Gardea-Torresdey, J1, Aldrich, M1, Peralta-Videa, J1, Parsons, J1, 1 Department of Chemistry and Environmental Science and Engineering PhD Program, University of Texas-El Paso, El Paso, Texas, USA
ABSTRACT- Chromium is a transition metal extensively used in industry. Cr mining and industrial operations account for chromium wastes at Superfund sites in the United States. Two separate studies were performed to investigate the possibility to use mesquite (Prosopis spp.), which is an indigenous desert plant species, to remove Cr from the contaminated environment. The first study was performed by growing mesquite on an agar-based medium containing 75 mg L-1 and 125 mg L-1 of Cr(VI). The accumulation found in the leaves (992 mg kg-1 of dry weight, from 125 mg L-1 of Cr(VI)) indicated that mesquite could be classified as a chromium hyperaccumulator. The second study was conducted to investigate the differences between the type of Cr ligand involved in Cr uptake from agar and hydroponics cultures. X-ray absorption spectroscopy (XAS) were used to determine the mechanisms involved in the uptake and binding of Cr(VI) in mesquite tissue. The XAS results from this study showed that some of the supplied Cr(VI) was uptaken by the mesquite roots; however, the data analyses of the plant tissues demonstrated that it was fully reduced to Cr(III) in the leaf tissues. Experiments are currently being performed to evaluate the behavior of Mesquite plant using lower Cr concentrations.
Key words: chromium, phytoremediation, Mesquite, XAS