Use of Festuca ovina L. in Chelate Assisted Phytoextraction of Copper Contaminated Soils
Authors
Abstract
Festuca ovina L. is a hyperaccumulating plant which has aroused considerable
interest with respect to its possible use for phytoremediation of contaminated soils. This
study has been conducted to evaluate the potentials of F. ovina L. to serve as a
phytoremediation plant in the cleaning up of Cu in the polluted soils and to identify
extraction efficiency of Ethylene Diamine Tetraacetic Acid (EDTA) for desorbing copper
in relation to chelator dosage. Seeds have been sown in control and Cu contaminated pots
(artificially contaminated with 150 mg kg-1 Cu). Results revealed that Cu negatively
affected growth and tolerance indices of F. ovina and the root length was the most
sensitive parameter among all measured parameters. The treatments used for assessing
EDTA efficiency were 1.5, 3, 6, 15+1.5, 3+3 mmolkg-1, control (C: uncontaminated soil
without EDTA) and W (contaminated soil without EDTA). Results showed that the
application of 1.5 mmolkg-1 of EDTA did not significantly improve the phytoextraction of
Cu and statistically, there was no significant difference in Cu uptake between single and
split applications of 1.5 mmolkg-1 of EDTA. A sharp increase in root Cu concentration was
observed when 3 mmolkg-1 of EDTA was applied. The highest amount of Cu extracted for
the plant tissues was achieved at the doses of 6 mmolkg-1 and 3+3 mmolkg-1 EDTA,
respectively. Higher Remediation Factors (RF) were obtained for the plants grown in
contaminated soil and the highest RFs (0.08% and 0.07%) were recorded after the addition
of 6 and 3+3 mmolkg-1, respectively. Application of EDTA showed a relatively decrease in
TI (Tolerance Index) value and the lowest value of TI was recorded in 6 mmolkg-1 EDTA
treatment. According to the experiment, EDTA has appeared to be an efficient amendment
when Cu phyto-extraction with F.ovina was addressed. But further studies would be
needed on investigating the reduction of percolation risk by the amount and process of
chelate application.
