Heavy hyperaccumulation

Phytoextraction has several advantages. The contaminants are permanently removed from the soil and the quantity of the waste material produced is substantially decreased. In some cases, the contaminant can be recycled from the contaminated biomass. However, the use of hyperaccumul-ating plants is limited by their slow growth, shallow root systems, and small biomass production. In order for this remediation scheme to be feasible, plants must tolerate high metal concentrations, extract large concentrations of heavy metals into their roots, translocate them into the surface biomass, and produce a large quantity of plant biomass. 

Brooks R. R., 1998, Plants that hyperaccumulate heavy metals, CAB International, University Press, Cambridge. 

T0229 Edenspace Systems Corporation, Hyperaccumulation of Metals T0279 Environmental Research and Development, Inc., Neutral Process for Heavy-Metals Removal... 

In June of 1999, Edenspace Systems Corporation acquired Phytotech, Inc., a company specializing in phytoremediation technologies. Phytotech has developed several proprietary techniques for the phytoremediation of sites contaminated with heavy metals and radionuclides. Phytoremediation is an emerging bioremediation technology that uses plants to remediate contaminated media. Hyperaccumulation is a specific type of phytoremediation that can be used at sites contaminated by radionuclides and heavy metals. Hyperaccumulation may be defined as the ability... 

Finally, because hyperaccumulators can accumulate relatively large quantities of heavy metals from the substrate, they could be used as decontaminating agents. A research group in the United States has already carried out trials with a Co hyperaccumulator in order to try to remove radioactive Co from contaminated soil. 

Brooks, R.R. and Robinson, B.H., The potential use of hyperaccumulators and other plants for phytomining, in Plants That Hyperaccumulate Heavy Metals, Brooks, R.R., Ed., CAB International, Wallingford, U.K., 1998, pp. 327-356. 

Bondada, B. and Ma, L.Q. 2003. Tolerance of heavy metals in vascular plants Arsenic hyperaccumulation by Chinese brake fem (Pteris vittata L.). In Chandra S. and Siivastava M. (eds), Pteridology in the New Millennium. Kluwer Academy Publishers, the Netherlands, pp. 397--f20. 

Lombi, E., Zhao, E.J., Dunham, S.J., and McGrath, S.P. 2001. Phytoremediation of heavy metal-contaminated soils Natural hyperaccumulation versus chemically enhanced phytoextraction. Journal of Environmental Quality, 30 1919-26. 

Yang, X., Feng, Y, He, Z., and Stoffella, P.J. 2005. Molecular mechanisms of heavy metal hyperaccumulation and phytoremediation. Journal of Trace Elements in Medicine and Biology, 18(4) 339-53. 

Y He, Z., and Stoffells, P.J., Molecular mechanisms of heavy metal hyperaccumulation and phytoremediation, J. Trace Elem. Med. Biol. 18, 339-353, 2005 Mackenzie, S.A., Plant organellar protein targeting a traffic plan still under construction. Trends Cell Biol. 15, 548-554, 2005 Thompson, M.V., Phloem the long and the short of it. Trends Plant Sci. 11, 26-32, 2006 Takahashi, H., Yoshimoto, N., and Saito, K., Anionic nutrient transport in plants the molecular basis of the sulfate transporter gene family. Genet. Eng. 27, 67-80, 2006. 

Serpentine soils have high levels of heavy metals (Ni, Co, Cr), and low levels of important plant nutrients (P, Ca, N). Because of these inhospitable conditions, serpentine soils support a specialized flora, including such plant species as the nickel hyperaccumulator Alyssum bertolonii. In a study that examined bacterial communities at various distances from A. bertolonii roots in different serpentine areas, it was found that the bacterial communities possessed high genetic diversity... 

Pence, N., Larsen, P., Ebbs, S., Letham, D., Lasat, M., Garvin, D., Eide, D., Kochian, L., 2000, The molecular physiology of heavy metal transport in the Zn/Cd hyperaccumulator Thlaspi caerulescens, Plant Biology, 97(9)4956 1960. 

There is now considerable interest in the area of metal transport in plants because of the implications for phytoremediation -the use of plants to extract, sequester, and/ or detoxify pollutants such as toxic metals. Phytoremediation strategies for radionuclide and heavy metal pollutants focus on hyperaccumulation above ground. Significant progress has been made in recent years in developing native or genetically modified plants for the remediation of environmental contaminants (Meagher 2000). 

Since the electric field efficiently drives increased amounts of soluble heavy metals toward plant roots, which results in stress conditions for plants, hyperaccumulator plants with a rapid growth period are candidates for use in combination... 

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