Electricity production coupled to ammonium in a microbial fuel cell.
The production of electricity from ammonium was examined using a rotating-cathode microbial fuel cell (MFC). The addition of ammonium chloride, ammonium sulfate, or ammonium phosphate (monobasic) resulted in electricity generation, while adding sodium chloride, nitrate, or nitrite did not cause any increase in current production. The peak current increased with increasing amount of ammonium addition up to 62.3 mM of ammonium chloride, suggesting that ammonium was involved in electricity generation either directly as the anodic fuel or indirectly as substrates for nitrifiers to produce organic compounds for heterotrophs. Adding nitrate or nitrite with ammonium increased current production compared to solely ammonium addition. Using 16S rRNA-linked molecular analyses, we found ammonium-oxidizing bacteria and denitrifying bacteria on both the anode and cathode electrodes, whereas no anammox bacteria were detected. The dominant ammonium-oxidizing bacteria were closely related to Nitrosomonas europaea. The present MFC achieved an ammonium removal efficiency of 49.2 +/- 5.9 or 69.7 +/- 3.6%, depending on hydraulic retention time, but exhibited a very low Coulombic efficiency.
He
Zhen
Z
Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
Kan
Jinjun
J
Wang
Yanbing
Y
Huang
Yuelong
Y
Mansfeld
Florian
F
Nealson
Kenneth H
KH
D001419:Bacteria / Q000378:metabolism*; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004560:Electricity; D004566:Electrodes / Q000382:microbiology; D004586:Electrophoresis; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000737:chemistry; D009573:Nitrites / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry* / Q000302:isolation & purification
D009566:Nitrates; D009573:Nitrites; D000644:Quaternary Ammonium Compounds