In:
Scientific Reports, Springer Science and Business Media LLC, Vol. 11, No. 1 ( 2021-01-12)
Abstract:
Nitrification is the rate limiting step in the nitrogen removal processes since nitrifiers have high oxygen demand, but poorly compete with aerobic heterotrophs. In a laboratory-scaled system, we investigated a process of ammonium oxidation under ferric-iron reducing condition (feammox) in the presence of organic carbon using influents with high NH 4 + and COD contents, and ferrihydrite as the only electron acceptor. Batch incubations testing influents with different NH 4 + and COD concentrations revealed that the [COD]/[NH 4 + ] ratio of 1.4 and the influent redox potential ranging from − 20 to + 20 mV led to the highest removal efficiencies, i.e. 98.3% for NH 4 + and 58.8% for COD. N 2 was detected as the only product of NH 4 + conversion, whereas NO 2 − and NO 3 − were not detected. While operating continuously with influent having a [COD]/[NH 4 + ] ratio of 1.4, the system efficiently removed NH 4 + ( 〉 91%) and COD ( 〉 54%) within 6 day retention time. Fluorescence in situ hybridization analyses using Cy3-labeled 16S rRNA oligonucleotide probes revealed that gamma-proteobacteria dominated in the microbial community attaching to the matrix bed of the system. The iron-reduction dependent NH 4 + and COD co-removal with a thorough conversion of NH 4 + to N 2 demonstrated in this study would be a novel approach for nitrogen treatment.
Type of Medium:
Online Resource
ISSN:
2045-2322
DOI:
10.1038/s41598-020-80057-y
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2021
detail.hit.zdb_id:
2615211-3
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