Impacts of storm disturbance and the role of the Feammox process in high nutrient riparian sediments

Abstract The extensive agricultural feedlot operations in the Neuse River Watershed (NRW) North Carolina result high nutrient loading, particularly of ammonium (NH 4 + ). In September 2018, Hurricane Florence devastated large portions NRW, creating a unique opportunity to study impact such hydrological events on biogeochemistry riverine and riparian sediments. NH concentrations, naturally acidic conditions, elevated levels ferric iron [Fe(III)] sediments soils provide an ideal environment for Acidimicrobium sp . A6 (referred hereon as A6), bacterium capable conducting Feammox process which is oxidized while reduced. was observed all sediment samples obtained from River, it therefore predicted that this may be important mechanism removal river system. Incubations NRW indicate oxidation potential via comparable with aerobic by heterotrophic microorganisms. Given demand Fe(III) process, has been unclear how occur sedimentary environments where might depleted. results presented here show major hydrologic storm event can increase abundance Fe-reducing bacteria, including A6. These findings may, delivery Fe(III), enhancing activity favor process.