Page 104 - Plant-Based Remediation Processes

5 Impact of Metal/Metalloid-Contaminated Areas on Plant Growth 93

5.4.1.5 Alyssum serpyllifolium (Brassicaceae)

The efficiency of Alyssum serpyllifolium subsp. lusitanicum for use in phyto-
extraction of polymetal-contaminated soils has been examined (Kidd and
Monterroso 2005). The plants have been grown on soils contaminated with Cr,
Cu, Pb, and Zn. The results suggest that A. serpyllifolium can be suitable for
phytoextraction in polymetal-polluted soils, provided that Cu concentrations are
not phytotoxic. However, with the hyperaccumulators available, decades are
needed to clean up contaminated sites.

5.4.1.6 Alyssum bertolonii (Brassicaceae) and Berkheya coddii (Asteraceae)

There are about 300 known species of Ni hyperaccumulators (Robinson et al.
1999), belonging to more than 33 families (Gramlich et al. 2011). Attractive plants
for phytoextraction of Ni are Alyssum bertolonii (Gramlich et al. 2011) and
Berkheya coddii (Moradi et al. 2010a). They are presented as effective plants on
a commercial scale to extract Ni. A. bertolonii is a serpentine endemic nickel-
hyperaccumulating plant with small biomass (Barzanti et al. 2011), while B. coddii
has high phytoextraction potential and is characterised by high biomass
1
(22 mg ha ) production (Moradi et al. 2010a). Unfortunately, there is little
information about the mechanism of Ni hyperaccumulation or about root–soil
interaction under Ni contamination (Moradi et al. 2010b). Knowledge and under-
standing of this issue could improve the results of phytoextraction methods for Ni.

5.4.1.7 Noaea mucronata (Chenopodiaceae)

N. mucronata is a typical dry desert shrub which grows in insufficient and poor soils
(Pen-Mouratov et al. 2008). N. mucronata also belongs to the xerohalophytes and is
the co-dominant plant over large areas. In recent years, the literature data have
shown that among the native plants grown in the studied polluted area (north west
of Iran), N. mucronata was found to be a good hyperaccumulator plant for Pb, Zn,
and Cd (Chehregani et al. 2009; Parizanganeh et al. 2010). The amounts of heavy
metals were decreased in polluted soils under the effect of N. mucronata, which
makes them an effective accumulator, especially a good Pb accumulator
(Chehregani et al. 2009).

5.4.2 Non-hyperaccumulators

Non-hyperaccumulators also have the possibility to accumulate significant amounts
of heavy metals in plant organs. For example, plants inhabiting sites near old