Characterization of the Microbial Ecology and the Mineralogy in the Surroundings of an Iron Barrier

摘要

The lifetime of zero-valent (Fe°) iron barriers is limited as corrosion of the iron grains and the subsequent precipitation of minerals can lead to loss of iron reactivity, reduced hydraulic conductivity, and the development of preferential flow. There is only little information on the microbial activity and dynamics within and in the surroundings of the Fe° barriers. Adaptation of indigenous bacteria and shifts in the microbial population structure are expected due to the strongly reducing Fe° environment and microorganisms can possibly affect barrier longevity in both a positive and negative way. Column-scale multifunctional permeable reactive barriers (MULTIBARRIERS), consisting of both aquifer and zero-valent iron compartments, were dismantled after .3 years and samples were taken for both microbial and mineralogical study. Main secondary phases that were.