Microbial transformation of biogenic and abiogenic Fe minerals followed by in-situ incubations in an As-contaminated vs. non-contaminated aquifer

• DOI: 10.1016/j.envpol.2021.117012
• Publication Date: 2021-03-26T04:51:58Z
• Authors: Martyna Glodowska; Magnus Schneider; Elisabeth Eiche; Agnes Kontny; Thomas Neumann; Daniel Straub; Sara Kleindienst; Andreas Kappler
• Keywords: Abiogenic petroleum origin; Geobacter

Fe(III) minerals play a crucial role for arsenic (As) mobility in aquifers as they usually represent the main As-bearing phases. Microbial reductive dissolution of is responsible release As and resulting groundwater contamination many sites worldwide. So far, most studies mainly abiogenic iron have been considered. Yet, biogenic that possess different properties to their counterparts are also present environment. In some environments dominate mineral inventory but so it unclear what this means mobility. We, therefore, performed an in-situ aquifer exposure experiment i) evaluate how transformed strongly reducing, As-contaminated (25 m) compared As-free moderately reducing (32 ii) assess which microbial taxa involved these transformations. We found higher numbers bacteria archaea were associated with incubated non-contaminated all colonized by Fe(III)-reducing bacteria, Geobacter being abundant taxon. Additionally, fermenting microorganisms on aquifer, while methanotrophs identified implying involvement reduction. observed generally tend become more reduced when sorbed than ones. Most into magnetite crystalline mixed phases not subjected visible transformation. This incubation approach shows prone be (Fe(III)-reducing) bind As, although ultimately produce similar during