Gentle soil remediation of trace element-contaminated soils - success stories from the greenland project
Résumé
Contamination of soils with trace elements (TE) is worldwide still one of the major environmental problems. Conventional technologies for soil remediation are usually very expensive and may negatively affect or destroy soil structure and functions. Phytoremediation technologies, however, include a set of gentle remediation options (GRO) which are approaches based on plants and associated microbes as well as soil amendments for remediating trace element-contaminated soils at low cost and without significant negative effects for the environment. The main technologies are phytoextraction, in situ immobilization and assisted phytostabilization. Although GRO comprise very innovative and efficient technologies, they are still not widely used as practical site solution due to several reasons of hindrance. Although major progress has been achieved on the lab scale, success stories obtained in the field are still limited, in particular regarding the long-term efficiency. Also, the issue of valorization of the potentially contaminated plant biomass has insufficiently been addressed so far. Furthermore, additional development is needed regarding the adequate determination of end-points of GRO. Finally, the application of GRO as practical site solution may be hindered by legal frameworks and by insufficient knowledge of the decision makers. Long term and large-scale field experiments may provide data required for the overall assessment of GRO efficiency, effectiveness and sustainability. Therefore, the EU-FP7-project “Gentle remediation of trace element-contaminated land – GREENLAND; www.greenland-project.eu) with 17 partners from 11 countries has been launched on January 1 2011 to address these issues and to make GRO ready for use as practical site solution.