1 Department of Biology, Faculty of Science, SDU2 Nordic Center for Earth Evolution (NordCEE), Department of Biology, Faculty of Science, SDU3 Max Planck Institute for Marine Microbiology, Microsensor Group4 Faculty of Civil and Environmental Engineering5 Max Planck Institute for Marine Microbiology, Microsensor Group6 Max Planck Institute for Marine Microbiology, Microsensor Group7 Department of Biology, Faculty of Science, SDU
The possible shift of a bioreactor for NO3- removal from predominantly denitrification (DEN) to dissimilatory nitrate reduction to ammonium (DNRA) by elevated electron donor supply was investigated. By increasing the C/NO3- ratio in one of two initially identical reactors, the production of high sulfide concentrations was induced. The response of the dissimilatory NO3- reduction processes to the increased availability of organic carbon and sulfide was monitored in a batch incubation system. The expected shift from a DEN- towards a DNRA-dominated bioreactor was not observed, also not under conditions where DNRA would be thermodynamically favorable. Remarkably, the microbial community exposed to a high C/NO3- ratio and sulfide concentration did not use the most energy-gaining process.
Bioresource Technology, 2014, Vol 171, Issue 1, p. 291-297
Dissimilatory nitrate reduction; Microbial aggregates; Sulfide; USB reactor