Kamolwan Pokaeo. The potential use of Eucalyptus (Eucalyptus camaldulensis dehn) for phytoremediation of lead. Master's Degree(Environmental Technology ). Mahidol University. : Mahidol University, 2008.
The potential use of Eucalyptus (Eucalyptus camaldulensis dehn) for phytoremediation of lead
Abstract:
The purpose of this research was to investigate the ability of eucalyptus
(Eucalyptus camaldulensis Dehn.), of age 3 months, for Pb bioremediation after
grown hydroponically with different Pb concentrations amended solution.
The ability of EDTA in enhancing Pb uptake and translocation within the plants for
60 days of exposure was also investigated. Furthermore, effects of Pb on plant
growth (shoot length and biomass dry weight), Pb accumulation (in roots, stems and
leaves), bioconcentration factors (BCFs) and translocation factors (TFs) were
studied.
The results revealed that the shoot length of eucalyptus increased
significantly (p value=0.006) whilst biomass revealed progressive decline. Likewise,
the relative growth of shoot length was ≥ 1 whereas the relative biomass was < 1
when compared with those obtained from the control. Furthermore, all of the growth
parameters were not significantly different in all treatments of increasing Pb
concentration.
At the Pb concentration of 20 mg L-1, the roots of eucalyptus were the main
site of Pb accumulation with Pb concentration of 6,483 mg kg-1dw, followed by
14.82 mg kg-1dw in leaves and 9.52 mg kg-1dw in stems. When EDTA was applied
(10 mg L-1), a high Pb concentration of 4,453 mg kg-1dw was still found in roots,
with the concentration of 24.57 mg kg-1dw and 23.20 mg kg-1dw found accumulated
in stems and leaves, respectively. Apparently, adding EDTA induced more
bioaccumulation in stems and leaves of eucalyptus (p value<0.001) as well as
increasing value of TFs. However, when compared with only Pb addition, Pb
content in root and the BCFs values grown in Pb with EDTA were reduced.
Furthermore, the increasing exposure times increased the level of Pb accumulation
in roots and the BCFs values, but gradually decreased in stems and leaves, as well as
the values of TFs (< 1) in all Pb treatments.
It can be concluded that Pb accumulation was mainly found in the roots in
comparison with other parts. Therefore, eucalyptus might be proposed as an
appropriate and potential technique of stabilizing Pb contaminated land
(phytostabilization) for phytoremediation.