TY - JOUR
T1 - Oxidation of ammonium by Feammox Acidimicrobiaceae sp. A6 in anaerobic microbial electrolysis cells
AU - Ruiz-Urigüen, Melany
AU - Steingart, Daniel Artemus
AU - Jaffé, Peter R.
N1 - Funding Information:
Funding for this research was provided by the Andlinger Center for Energy and the Environment and by the Princeton Environmental Institute. The Instituto de Fomento al Talento Humano – Ecuador and the Mary and Randall Hack'69 Research Grant provided funding for Melany Ruiz-Urigüen. We thank Dr. Bruce Logan for providing the first MEC reactors that were used as prototypes for the MECs used here and for his insightful ideas, Dr. Xiuping Zhu for her valuable advice on the MEC set-up, and Dr. Jason Ren and Dr. Lu Lu for their advice on MEC operation and this manuscript. We thank Dr. Chen Chen from the South China Environmental Institute for her collaboration on sequencing. From Princeton University, we thank Dr. Shan Huang for maintaining and providing A6 cultures and all members from the Steingart group for their assistance in the set-up of the electrochemical analysis. The authors acknowledge the use of Princeton's Imaging and Analysis Center, which is partially supported by the Princeton Center for Complex Materials, a National Science Foundation (NSF)-MRSEC program (DMR-1420541), and Florence Ling for her assistance in using the E-SEM.
Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019/9
Y1 - 2019/9
N2 - Anaerobic ammonium oxidation under iron reducing conditions, also referred to as Feammox, can be carried out by the recently isolated Acidimicrobiaceae sp. A6 (A6). Ammonium is a common water pollutant which is typically removed by nitrification, a process that exerts a high oxygen demand in waste treatment systems. A6 oxidizes ammonium anaerobically using ferric iron [Fe(iii)] as an electron acceptor and has also been shown to be an electrode (anode) colonizing bacterium. Results presented here demonstrate that A6, in a pure or enrichment culture, can thrive in microbial electrolysis cells (MECs) by oxidizing ammonium, while using the anode as an electron acceptor. Results also show that current production and ammonium removal increase with the concentration of 9,10-anthraquinone-2,6-disulfonic acid (AQDS), a soluble electron shuttling compound, which is especially noticeable for the pure A6 culture. Electron microscopy of the anode's surface reveals attached cells in the pure culture MEC; however, over the time of operation there is no formation of a biofilm and the majority of cells are in the bulk liquid, explaining the need for AQDS. Maximum coulombic efficiencies of 16.4% and a current density of 4.2 A m-3 were measured. This is a first step towards the development of a Feammox bacteria-based bioelectrochemical system for anaerobic ammonium oxidation while reducing electrodes instead of Fe(iii).
AB - Anaerobic ammonium oxidation under iron reducing conditions, also referred to as Feammox, can be carried out by the recently isolated Acidimicrobiaceae sp. A6 (A6). Ammonium is a common water pollutant which is typically removed by nitrification, a process that exerts a high oxygen demand in waste treatment systems. A6 oxidizes ammonium anaerobically using ferric iron [Fe(iii)] as an electron acceptor and has also been shown to be an electrode (anode) colonizing bacterium. Results presented here demonstrate that A6, in a pure or enrichment culture, can thrive in microbial electrolysis cells (MECs) by oxidizing ammonium, while using the anode as an electron acceptor. Results also show that current production and ammonium removal increase with the concentration of 9,10-anthraquinone-2,6-disulfonic acid (AQDS), a soluble electron shuttling compound, which is especially noticeable for the pure A6 culture. Electron microscopy of the anode's surface reveals attached cells in the pure culture MEC; however, over the time of operation there is no formation of a biofilm and the majority of cells are in the bulk liquid, explaining the need for AQDS. Maximum coulombic efficiencies of 16.4% and a current density of 4.2 A m-3 were measured. This is a first step towards the development of a Feammox bacteria-based bioelectrochemical system for anaerobic ammonium oxidation while reducing electrodes instead of Fe(iii).
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U2 - 10.1039/c9ew00366e
DO - 10.1039/c9ew00366e
M3 - Article
AN - SCOPUS:85071329977
SN - 2053-1400
VL - 5
SP - 1582
EP - 1592
JO - Environmental Science: Water Research and Technology
JF - Environmental Science: Water Research and Technology
IS - 9
ER -