TY - JOUR
T1 - The Importance of Microbial Iron Sulfide Oxidation for Nitrate Depletion in Anoxic Danish Sediments
AU - Vaclavkova, Sarka
AU - Jacobsen, Ole Stig
AU - Jørgensen, Christian Juncher
AU - Aamand, Jens
AU - Elberling, Bo
PY - 2014/7
Y1 - 2014/7
N2 - Nitrate (NO3 −) reduction processes are important for depleting the NO3 −
load from agricultural source areas before the discharge water reaches
surface waters or groundwater aquifers. In this study, we experimentally
demonstrate the co-occurrence of microbial iron sulfide oxidation by NO3 − (MISON) and other NO3 −-depleting
processes in a range of contrasting sediment types: sandy groundwater
aquifer, non-managed minerotrophic freshwater peat and two brackish
muddy sediments. Approximately 1/3 of the net NO3 −
reduction was caused by MISON in three of the four environments despite
the presence of organic carbon in the sediment. An apparent salinity
limitation to MISON was observed in the most brackish environment.
Addition of high surface area synthetically precipitated iron sulfide
(FeS x ) to the aquifer sediment with the lowest natural FeS x reactivity increased both the relative fraction of NO3 −
reduction linked to MISON from approximately 30–100 % and the absolute
rates by a factor of 17, showing that the potential for MISON-related NO3 − reduction is environmentally significant and rate limited by the availability of reactive FeS x
AB - Nitrate (NO3 −) reduction processes are important for depleting the NO3 −
load from agricultural source areas before the discharge water reaches
surface waters or groundwater aquifers. In this study, we experimentally
demonstrate the co-occurrence of microbial iron sulfide oxidation by NO3 − (MISON) and other NO3 −-depleting
processes in a range of contrasting sediment types: sandy groundwater
aquifer, non-managed minerotrophic freshwater peat and two brackish
muddy sediments. Approximately 1/3 of the net NO3 −
reduction was caused by MISON in three of the four environments despite
the presence of organic carbon in the sediment. An apparent salinity
limitation to MISON was observed in the most brackish environment.
Addition of high surface area synthetically precipitated iron sulfide
(FeS x ) to the aquifer sediment with the lowest natural FeS x reactivity increased both the relative fraction of NO3 −
reduction linked to MISON from approximately 30–100 % and the absolute
rates by a factor of 17, showing that the potential for MISON-related NO3 − reduction is environmentally significant and rate limited by the availability of reactive FeS x
U2 - 10.1007/s10498-014-9227-x
DO - 10.1007/s10498-014-9227-x
M3 - Journal article
SN - 1380-6165
VL - 20
SP - 419
EP - 435
JO - Aquatic Geochemistry
JF - Aquatic Geochemistry
IS - 4
ER -
