Biotechnological Aspects of Soil Decontamination - Biotechnologies and Biomimetics for Civil Engineering - page 387

Table 17.4 Some of the plants with potential for phytovolatilization of Hg and Se
Plant species Metals References

Arabidopsis thaliana Hg Rugh et al. ( 1996 )

Liriondendron tulipifera Rugh et al. ( 1998 )

Nicotiana tabacum
Astragalus racemosus Se Evans et al. ( 1968 )

Brassica juncea Pilon-Smits ( 2005 )

Salicornia bigelowii Pilon-Smits et al. ( 1999 )

Typha latifolia

Fig. 17.3 Schematic
diagram showing mechanism
of phytoextraction

For phytostabilization, the normal practice is to choose drought-resistant, fast
growing crops or fodder, which can grow in metal contaminated and nutrient
deficient soils. Plant should also be poor translocator of metal contaminants to
above-ground plant tissues that could be consumed by humans or animals, the lack
of appreciable metals in shoot tissues also eliminates the necessity of treating
harvested shoot residue as hazardous waste. Metal tolerant plant species
(Table 17.4 ) immobilize heavy metals through adsorption and accumulation by
roots, absorption on to roots, or precipitation within the rhizosphere (Flathman and
Lanza 1998 ). Phytostabilization also involves soil amendments (organic matter) to
promote the formation of insoluble metal complexes that reduce biological
availability and plant uptake, thus preventing metals from entering the food chain
(Berti and Cunningham 2000 ).