TY - JOUR
T1 - Ubiquitous Presence of Fe(II) in Aquatic Colloids and Its Association with Organic Carbon
AU - Von Der Heyden, Bjorn P.
AU - Hauser, Emily J.
AU - Mishra, Bhoopesh
AU - Martinez, Gustavo A.
AU - Bowie, Andrew R.
AU - Tyliszczak, Tolek
AU - Mtshali, Thato N.
AU - Roychoudhury, Alakendra N.
AU - Myneni, Satish Chandra Babu
N1 - Publisher Copyright:
© 2014 American Chemical Society.
PY - 2014/8/29
Y1 - 2014/8/29
N2 - Despite being thermodynamically less stable, small ferrous colloids (60 nm to 3 μm in diameter) remain an important component of the biogeochemical cycle at the Earth's surface, yet their composition and structure and the reasons for their persistence are still poorly understood. Here we use X-ray-based Fe L-edge and carbon K-edge spectromicroscopy to address the speciation and organic-mineral associations of ferrous, ferric, and Fe-poor particles collected from sampling sites in both marine and freshwater environments. We show that Fe(II)-rich phases are prevalent throughout different aquatic regimes yet exhibit a high degree of chemical heterogeneity. Furthermore, we show that Fe-rich particles show strong associations with organic carbon. The observed association of Fe(II) particles with carboxamide functional groups suggests a possible microbial role in the preservation of Fe(II). These finding have significant implications for the behavior of Fe(II) colloids in oxygenated waters, and their role in different aquatic biogeochemical processes.
AB - Despite being thermodynamically less stable, small ferrous colloids (60 nm to 3 μm in diameter) remain an important component of the biogeochemical cycle at the Earth's surface, yet their composition and structure and the reasons for their persistence are still poorly understood. Here we use X-ray-based Fe L-edge and carbon K-edge spectromicroscopy to address the speciation and organic-mineral associations of ferrous, ferric, and Fe-poor particles collected from sampling sites in both marine and freshwater environments. We show that Fe(II)-rich phases are prevalent throughout different aquatic regimes yet exhibit a high degree of chemical heterogeneity. Furthermore, we show that Fe-rich particles show strong associations with organic carbon. The observed association of Fe(II) particles with carboxamide functional groups suggests a possible microbial role in the preservation of Fe(II). These finding have significant implications for the behavior of Fe(II) colloids in oxygenated waters, and their role in different aquatic biogeochemical processes.
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U2 - 10.1021/ez500164v
DO - 10.1021/ez500164v
M3 - Article
AN - SCOPUS:84969220080
SN - 2328-8930
VL - 1
SP - 387
EP - 392
JO - Environmental Science and Technology Letters
JF - Environmental Science and Technology Letters
IS - 10
ER -