University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Eila Gendig
(2011):
Phytoextraction of Cadium, Lead and Zinc by two hyperaccumulator species and metal bioavailability in the rhizosphere.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 43.
UB BOKU
obvsg
FullText
- Abstract:
- Contaminated soils pose a potential threat to any ecosystem and to biota. Phytoextraction – the use of (hyper-)accumulating plants to extract the contaminant(s) – is being discussed as a low-cost technique for in-situ clean-up of polluted soils. The metal-hyperaccumulator species Arabidopsis halleri and Thlaspi caerulescens were grown on two Fluvisols with different levels of metal pollution, in order to determine their phytoextraction potential and associated changes in bioavailable cadmium, lead and zinc concentrations in the rhizosphere. Both plants were able to accumulate >4000 mg Zn kg 1 dry matter (d.m.) and >100 mg Cd kg-1 d.m. in their shoots, and, with few exceptions, bioconcentration and translocation factors were >1. In contrast, accumulation and translocation of lead by both plant species were small. Independent of the soil trace metal concentration, the bioconcentration factor for cadmium and the cadmium content in biomass of T. caerulescens were higher than those of A. halleri. The translocation and bioconcentration factors for zinc and the zinc concentration in biomass were highest in A. halleri on the highly contaminated soil. T. caerulescens accumulated 42 % and 18 % of total soil cadmium during the 14 weeks of the experiment when grown on heavily and less polluted soil, respectively. Phytoextraction of zinc amounted to roughly 5 % of total zinc content in the root penetrated soil volume. However, the potential to remove zinc was dependent on the level of soil contamination as A. halleri absorbed more zinc on heavily polluted soil and T. caerulescens was superior on the soil with low trace metal concentration. The observed mobilisation of trace metals in the rhizosphere of A. halleri on highly polluted soil might be the consequence of distinct root activities. The results of this study confirm the high phytoextraction potential for cadmium and zinc of the investigated metal hyperaccumulator species and reveal the complex interaction with soil pollutant levels that needs to be addressed in the application of phytoextraction technologies
- Beurteilende(r): Wenzel Walter