Das Projekt "Biologische Dekontamination schwermetallbelasteter Boeden mit Hyperakkumulatoren: Beeinflussung der Schwermetallaufnahme im Wurzelraum" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich (ETHZ), Institut für Terrestrische Ökologie ITOE durchgeführt. Remediation of heavy-metal polluted agricultural soils requires gentle methods, i.e. methods by which the fertility of the soil is fully restored. This means that harsh methods such extraction of metal pollutants by strong acids or soil washing are not applicable as they do not only remove the pollutants, but also destroy the physical and chemical basis of soil fertility, e.g. soil structure and cation exchangers, as well. Soil cleaning by methal harvesting through accumulator plants is a promising technique for the gentle remediation of heavy metal contaminated soils. Up to now one major problem of this technique has been however the comparatively low productivity of candidate accumulator plants under field conditions. In this project we investigate possibilities to improve the efficiency of this method by enhancing the availability of the pollutants for the roots of the accumulator plants, i.e. by applying mobilizing additives such as chelator agents or by optimizing root growth through classical agricultural techniques such as soil preparation, fertilization and harvesting regimes. Leading Questions: Can metal-accumulating plants be used to clean-up heavy-metal polluted calcareous soils for agricultural or similar re-use?
Das Projekt "Wurzelbildungsstrategie und Schwermetallaufnahme von metallakkumulierenden Pflanzen fuer die Phyto-Sanierung kontaminierter landwirtschaftlicher Standorte" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Terrestrische Ökologie, Fachbereich Bodenschutz durchgeführt. Extraction of metals from polluted agricultural soils by means of plants is in general limited either by low growth of hyper accumulating plants or low metal-uptake of plants with high biomass production. Moreover, metal-uptake is often much less efficient under field conditions than in pot experiments using the same soils. Rooting strategy was suspected as an important factor for the differences in metal uptake efficiency of different plants and under different conditions of soil structure and heterogeneity. In this project we compared the root growth and metal uptake of hyper accumulators with non- or low-accumulating plants, using agar, model soil and real soil systems.