Evaluation of metal uptake factors of native trees colonizing an abandoned copper mine – a quest for phytostabilization

Accumulation and enrichment of heavy metals in the above ground parts of Australian native Acacia pycnantha (Ap) and Eucalyptus camaldulensis (Ec) growing in an abandoned copper mine located in Kapunda, South Australia have been studied. Cu and other metals (Na, Al, K, Ca, Fe, Zn, Cd and Pb) in plants and corresponding soils were analysed to evaluate plant interaction with soils containing heavy metals. As per the total metal analysis of leaf and corresponding soil samples, Ap accumulated 93.6 mg kg−1 of Cu in leaf while the corresponding soil concentration was 1632 mg kg−1. The Ec accumulated 5341 mg kg−1 of Cu in leaf while the concentration of this heavy metal in soil was 65 mg kg−1 in soil. The ESEM spectral analysis also showed a high leaf concentration of Cu in Ec (7%) as against only 0.12% in Ap. The average bioconcentration factor for Cu, Zn, Cd and Pb in Ec was much higher than that of Ap. Similarly, enrichment factor was more in Ec for Cu, Zn and Pb than in Ap. In contrast, translocation factor for only Zn and Cd was high in Ap. This study points out that Ec and Ap have different stabilising potential in remediating heavy metals like Cu in mined soils.

The translocation factor (TF), also called shoot-root quotient, explains an ability of a plant to translocate the metal from roots through shoots and leaves of a plant which is primarily responsible for phytoextraction. Inter-relationship between processes of phytoremediation.Figure optionsDownload as PowerPoint slide