An integrated experiment coupling iron/argillite interactions with bacterial activity

International audienceIn the context of the safety assessment of radioactive waste geological disposal in clayey formations, the evolution in time and space of clayey and metallic materials is of concern regarding their containment properties. Bacteria may induce localized corrosion processes and clay mineral alteration. Moreover, the presence of heterogeneities may favor preferential pathways or higher reactivity. Thus, the objective of the present work is to assess the influence of bacteria and heterogeneities on iron-clay reactivity. Two percolation cells are conducted in the presence of iron and argillite involving an artificial crack in biotic or abiotic conditions at 60 °C during one year. Two bacteria have been selected: a Sulphate Reducing Bacteria (SRB) and an Iron Reducing Bacteria (IRB). The reactivity of those cells is evidenced by the ongoing monitoring of water composition. First results clearly show that bacteria are able to survive in the biotic experiment. Moreover, the decrease of the flow rate observed in each cell could be explained by the clogging of the crack