Passive reactive barriers, groundwater

A permeable reactive barrier (PRB) is defined as an in situ method for remediating contaminated groundwater that combines a passive chemical or biological treatment zone with subsurface fluid flow management. Treatment media may include zero-valent iron, chelators, sorbents, and microbes to address a wide variety of groundwater contaminants, such as chlorinated solvents, other organics,... 

Permeable reactive barriers have significant advantages over the conventional approaches for groundwater remediation. The barriers are passive systems whose effectiveness can persist for several years to decades. Moreover, the reactive material can be adjusted to target specific contaminants from a mine site and the contaminants precipitated within the barrier are isolated from the surface-water environment and biota (Blowes et al., 2000). 

Passivation of iron granulates in permeable barriers used for in situ groundwater remediation may result in a shorter life time and in contaminant breakthrough earlier than expected. Therefore, mineral reactions or generally the effect of other groundwater constituents on the long term reactivity of iron is of major interest for the application of this technology in environmental clean up. For interpretation of column experiments it is also important to estimate the effect of flow velocity on the extent of passivation due to mineral reactions. 

---