Development of Groundwater Rehabilitation Technologies with Injectable Fe-based Materials – AQUAREHAB WP5

Within the AQUAREHAB project WP5 focused on the development of groundwater rehabilitation technologies with injectable Fe-based micro- (100 nm < d < 100 µm) and nanoscale particles (< 100 nm). The idea was to inject small sized particles into the subsurface where they spread over a certain distance before sedimenting or attachment to the aquifer matrix. They then either directly react with the present contaminants or build a permeable reactive zone where the dissolved contaminants (plume) are being degraded.The advantage of this technology is that installing these zones or barriers via injection is fairly inexpensiveand not intrusive (in other words, the beneficial usage of the site is not disturbed by remediation efforts). Within the last four years, two strategies were pursued: (1) The use of reducingFe-based particles for reductive dehalogenation of chlorinated solvents. This technology is based upon the state of the art technology of reactive permeable barriers. Hence, the research could be based upon a strong foundation and, as planned, resulted in the successful demonstration on two field sites; (2) Application ofiron oxide particles as electron acceptors for oxidative biodegradation of BTEX contaminants. This technology was totally novel, hence it did not yield a field application within the frame of AQUAREHAB. Nevertheless, the outcomes of AQUAREHAB facilitated the development of this approach to a point where field applications were ready for application. Both approaches were accompanied by the development of monitoring technologies and ecotoxicology studies.