Info new type zerovalent iron

The capacity of zerovalent iron to degrade a number of chlorinated compounds abiotically via reductive dehalogenation has been studied intensively. Granular particles (millimeter size) have been used mostly and are installed in Permeable Reactive Barriers (PRBs) where soil material has to be excavated and replaced by the reactive particles. Smaller sized reactive particles (nano and lower micro scale) can be injected in the subsurface, creating reactive zones) and can have a number of advantages compared to granular ones. As for injectable small sized reactive particles no excavation is required, their application is as such less invasive and potentially economically more attractive. In addition, smaller particles have higher specific surface areas and are more reactive. Not only higher degradation rates are measured, but also a wider range of pollutants can be abated. On the other hand, smaller sized particles themselves are more costly and have a shorter life time. Within the AQUAREHAB project research was described to investigate the potential of especially micro-scale zerovalent iron particles, which have a number of advantages as compared to nano-scale (lower cost, longer storage times, higher reproducibility and longer lifetime), but they have a less high reactivity for the same mass of reagent.

Efforts were made by VITO and Höganäs to select and develop reactive injectable particles. New reactive particles were developed for which a patent application was made. Improved reactivity was shown via lab scale degradation experiments.

Contact details: per-olof.larsson@hoganas.com & leen.bastiaens@vito.be