Kinetic affinity index informs the divisions of nitrate flux in aerobic denitrification

AbstractTo overcome the problem that ferrous complexes are easily oxidized by O2 and then lose NO binding ability in the chemical absorption-biological reduction (CABR) process, cobalt(II)-histidine [Co(II)His] was proposed as an alternative. To evaluate the applicability of Co(II)His, the effects of CoHis absorbent on the aerobic denitrification by Paracoccus versutus LYM were investigated. Results indicated that His significantly promoted nitrite reduction. The inhibition effects of CoHis absorbent could be substantially alleviated by increasing the initial His/Co2+ to 4 or higher. CoHis with concentrations of 4, 8, 12, 16 and 20 mM presented no distinct effect on nitrite reduction, but slightly inhibited the reduction of nitrate, resulting in longer lag of nitrate reduction, and obviously promoted the growth of strain LYM. In the presence of 5, 10, 15 and 20 mM CoHis absorbent, the main denitrification product was N2 (not less than 95.0%). This study is of significance in verifying the applicability of Co(II)His in the CABR process, and provides a referable CoHis absorbent concentration as 20 mM with an initial His/Co2+ of 4 for the future experiments.

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Aerobic denitrification by Paracoccus sp. YF1 in the presence of Cu(II)

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.12.225 ◽

2019 ◽

Vol 658 ◽

pp. 80-86 ◽

Cited By ~ 5

Author(s):

Zeyang Lu ◽

Li Gan ◽

Jiajiang Lin ◽

Zuliang Chen

Keyword(s):

Aerobic Denitrification

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Screening and Characterization of a Bacterium Capable of Simultaneous Heterotrophic Nitrification and Aerobic Denitrification at High Concentrations of Ammonia-Nitrogen

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.665.487 ◽

2014 ◽

Vol 665 ◽

pp. 487-490

Author(s):

Te Wang ◽

Zhao Xia Liu ◽

Mei Juan Wu ◽

Fu Hui Kang ◽

Qing Chen ◽

...

Keyword(s):

16S Rdna ◽

Ammonia Nitrogen ◽

Heterotrophic Nitrification ◽

Denitrification Rate ◽

Aerobic Denitrification ◽

Optimal Conditions ◽

Carbon And Nitrogen ◽

Mass Ratios ◽

High Concentrations ◽

Denitrification Process

A bacterium capable of simultaneous heterotrophic nitrification and aerobic denitrification at high concentrations of ammonia-nitrogen was screened and identified and the denitrification property was investigated in this paper. The strain was isolated from aeration tank of wastewater disposed by activated sludge and analyzed and identified by 16S rDNA. The effects of different carbon sources and carbon and nitrogen mass ratios on denitrification rate were studied. The changes of various forms of ammonia-nitrogens during the simultaneous heterotrophic nitrification and aerobic denitrification process were characterized. A strain capable of simultaneous heterotrophic nitrification and aerobic denitrification at 600 mg/L nitrogen concentration has been isolated and screened. Comparison of its 16S rDNA sequence showed 100% similarity to Bacillus licheniformis strain Lr124/6. The strain was named as Bacillus sp. A22. The optimal conditions for degradation of ammonia-nitrogen by Bacillus sp. A22 were trisodium citrate as carbon source and carbon and nitrogen mass ratios of 10. The denitrification rate was 98.2% after 96 h of culture under the optimal conditions and there was hardly any intermediates accumulation in the denitrification process. It has practical applications that the denitrification can be performed efficiently at high concentrations of ammonia-nitrogen by method of simultaneous heterotrophic nitrification and aerobic denitrification by Bacillus sp. A22 in nitrogen purification treatment of wastewater with high concentrations of ammonia-nitrogen.

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