Publication Details

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Title (Primary) Anoxic nitrogen cycling in a hydrocarbon and ammonium contaminated aquifer
Author Wells, N.S.; Kappelmeyer, U.; Knöller, K.;
Journal Water Research
Year 2018
Department UBT; CATHYD;
Volume 142
Language englisch;
POF III (all) T41;
Keywords Contaminated groundwater; Stable isotopes; Nitrite; Chemolithotrophic N cycling; Biodegradation; Nitrate dual isotopes
Abstract Nitrogen fate and transport through contaminated groundwater systems, where N is both ubiquitous and commonly limits pollutant attenuation, must be re-evaluated given evidence for new potential microbial N pathways. We addressed this by measuring the isotopic composition of dissolved inorganic N (DIN = NH4+, NO2, and NO3) and N functional gene abundances (amoA, nirK, nirS, hszA) from 20 to 38 wells across an NH4+, hydrocarbon, and SO42− contaminated aquifer. In-situ N attenuation was confirmed on three sampling dates (0, +6, +12 months) by the decreased [DIN] (4300 - 40 μM) and increased δ15N-DIN (5‰–33‰) over the flow path. However, the assumption of negligible N attenuation within the plume was complicated by the presence of alternative electron acceptors (SO42−, Fe3+), both oxidizing and reducing functional genes, and N oxides within this anoxic zone. Active plume N cycling was corroborated using an NO2 dual isotope based model, which found the fastest (∼10 day) NO2 turnover within the N and electron donor rich central plume. Findings suggest that N cycling is not always O2 limited within chemically complex contaminated aquifers, though this cycling may recycle the N species rather than attenuate N.
ID 20472
Persistent UFZ Identifier http://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=20472
Wells, N.S., Kappelmeyer, U., Knöller, K. (2018):
Anoxic nitrogen cycling in a hydrocarbon and ammonium contaminated aquifer
Water Res. 142 , 373 - 382