Use of Festuca ovina L. in Chelate Assisted Phytoextraction of Copper Contaminated Soils

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Festuca ovina L. is a hyperaccumulating plant which has aroused considerableinterest with respect to its possible use for phytoremediation of contaminated soils. Thisstudy has been conducted to evaluate the potentials of F. ovina L. to serve as aphytoremediation plant in the cleaning up of Cu in the polluted soils and to identifyextraction efficiency of Ethylene Diamine Tetraacetic Acid (EDTA) for desorbing copperin 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 negativelyaffected growth and tolerance indices of F. ovina and the root length was the mostsensitive parameter among all measured parameters. The treatments used for assessingEDTA efficiency were 1.5, 3, 6, 15+1.5, 3+3 mmolkg-1, control (C: uncontaminated soilwithout EDTA) and W (contaminated soil without EDTA). Results showed that theapplication of 1.5 mmolkg-1 of EDTA did not significantly improve the phytoextraction ofCu and statistically, there was no significant difference in Cu uptake between single andsplit applications of 1.5 mmolkg-1 of EDTA. A sharp increase in root Cu concentration wasobserved when 3 mmolkg-1 of EDTA was applied. The highest amount of Cu extracted forthe 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 incontaminated soil and the highest RFs (0.08% and 0.07%) were recorded after the additionof 6 and 3+3 mmolkg-1, respectively. Application of EDTA showed a relatively decrease inTI (Tolerance Index) value and the lowest value of TI was recorded in 6 mmolkg-1 EDTAtreatment. According to the experiment, EDTA has appeared to be an efficient amendmentwhen Cu phyto-extraction with F.ovina was addressed. But further studies would beneeded on investigating the reduction of percolation risk by the amount and process ofchelate application.