Microstructural Characterization of Granular Cast Iron for Permeable Reactive Barriers

Abstract

AbstractAlthough intensive research on Fe(0) permeable reactive barriers (PRB) for in situ groundwater remediation has been conducted and multiple applications have been installed in the past two decades, some properties of reactive materials in use have not been fully considered and discussed yet. In the present investigation, a typical granular cast iron has been characterized with different techniques. The grain size distribution not only has an influence on the resulting pore geometry and the surface area but material properties significantly differ between fine and coarse grains. Metallographic analyses revealed large differences in both graphite inclusions and microstructures that likely influence the reactivity. Both graphite and cementite proved to be more resistant toward acidic dissolution compared to Fe0. The intrinsic material characteristics described here have not been covered in the existing PRB literature.