Gas generation from groundwater interaction with an iron treatment wall, Fry Canyon, Utah, USA

Gas generation from groundwater interaction with a field-scale zero-valent iron permeable reactive barrier (ZVI PRB) was measured and simulated with the geochemical reaction path model PHREEQC. Due to anaerobic corrosion of Fe (0) within the ZVI PRB, measured total dissolved gas (TDG) pressure exceeded hydrostatic pressure resulting in ebullition and depletion in dissolved noble gases. Geochemical modeling indicates that Fe (0)corrosion coupled withCH 4(g)production simulates the measured partial pressures ofCH 4(g) within the ZVI PRB required to exceed the hydrostatic pressure. Decreases in Ne(g) and Ar(g) in groundwater from the ZVI PRB indicate that the over pressuring from CH 4(g) production has been sufficient for bubble formation and subsequent ebullition.