6 research outputs found
Accumulation and translocation capacity of As, Co, Cr and Pb by forage plants
Over the last decades environmental levels of
As, Cr, Pb and Co heavily increased. They are naturally present in
ecosystems but also released by numerous human activities. The high
concentration inside the environment has caused not wanted accumulation
inside the biosphere. Their toxicity has contaminated several food
chains with consequent damage. Animal slurries are particularly rich
in Co, while the Cr main sources of pollution are represented by phosphate
fertilizers and metallurgical industry emissions, which can contain
over 1000 mg kg-1 Cr. Activities like mining, industrial emissions and
application of insecticides and fertilisers have contributed to increase
levels of heavy metals in soils (Alloway, 1994). Consequently these
soils cannot be used for crop production without cleaning up and before
measuring the metal concentration (Buxton, 1996; Niu et al., 2006).
Researches demonstrated that crop cultivation can accumulate metals in
their parts (Khattak et al., 1991; Hartley and Lepp, 2008).
Medicago sativa has been tested for its metal uptake capacity. In
a soil contaminated with 0-40 mg Cr kg-1 and other metals, Peralta-
Videa et al. (2001, 2002, 2003) have shown that M. sativa is able to
germinate and grow. Bioconcentration factors (BCF) and translocation
factors (TF) can be used to estimate plant ability to accumulate metals
from soils.
The overall objectives of the present research were: (i) to determine
the concentration of As, Co, Cr and Pb in plant biomass of Trifolium incarnatum (Crimson clover), Medicago sativa (Alfalfa), and mix for
forage growing on a contaminated soil; (ii) to compare the metal concentrations
in the aboveground biomass to those in roots and in soils (BCF,
TF); (iii) to verify the removal efficiency from the soil, by comparing
soil metal concentration before and after plant growing and harvesting