Enhanced nitrogen removal from high-strength ammonium wastewater by improving heterotrophic nitrification-aerobic denitrification process: Insight into the influence of dissolved oxygen in the outer layer of the biofilm

2021 ◽  
Vol 297 ◽  
pp. 126658
Author(s):  
PengYing Xiao ◽  
Jing Zhou ◽  
Xiaojing Luo ◽  
Baowen Kang ◽  
Lei Guo ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Removal ◽  
Outer Layer ◽  
High Strength ◽  
Heterotrophic Nitrification ◽  
Aerobic Denitrification ◽  
Insight Into ◽  
Denitrification Process

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

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.

scholarly journals Identification and Characterization of Janthinobacterium svalbardensis F19, a Novel Low-C/N-Tolerant Denitrifying Bacterium

2019 ◽  
Vol 9 (9) ◽  
pp. 1937 ◽  
Author(s):  
Yinyan Chen ◽  
Peng Jin ◽  
Zhiwen Cui ◽  
Tao Xu ◽  
Ruojin Zhao ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Pcr Amplification ◽  
Domestic Wastewater ◽  
Heterotrophic Nitrification ◽  
Aerobic Denitrification ◽  
Nitrite Accumulation ◽  
Specific Pcr ◽  
Domestic Wastewater Treatment ◽  
Initial Ph

Herein, we isolated Janthinobacterium svalbardensis F19 from sludge sediment. Strain F19 can simultaneously execute heterotrophic nitrification and aerobic denitrification under aerobic conditions. The organism exhibited efficient nitrogen removal at a C/N ratio of 2:1, with an average removal rate of 0.88 mg/L/h, without nitrite accumulation. At a C/N ratio of 2, an initial pH of 10.0, a culturing temperature of 25 °C, and sodium acetate as the carbon source, the removal efficiencies of ammonium, nitrate, nitrite, and hydroxylamine were 96.44%, 92.32%, 97.46%, and 96.69%, respectively. The maximum removal rates for domestic wastewater treatment for ammonia and total nitrogen were 98.22% and 92.49%, respectively. Gene-specific PCR amplification further confirmed the presence of napA, hao, and nirS genes, which may contribute to the heterotrophic nitrification and aerobic denitrification capacity of strain F19. These results indicate that this bacterium has potential for efficient nitrogen removal at low C/N ratios from domestic wastewater.

Microbiological conversions in nitrogen removal

1998 ◽  
Vol 38 (1) ◽  
pp. 1-7 ◽  
Author(s):  
M. C. M. Van Loosdrecht ◽  
M. S. M. Jetten
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Organic Substrate ◽  
Heterotrophic Nitrification ◽  
Aerobic Denitrification ◽  
Ammonium Oxidation ◽  
Treatment Processes ◽  
Nitrogen Conversion ◽  
The Many ◽  
Wastewater Treatment Systems

Nitrogen conversion processes are essential for most wastewater treatment systems. Due to the many possible conversions, and the complexity of analysing the reactions under actual conditions, there is much room for confusion. This review provides an overview of the possible microbiological nitrogen conversions described in literature. The relevance of these conversions with respect to wastewater treatment processes is discussed. Rates described for aerobic denitrification or denitrification by autotrophic nitrifiers are so low that these conversions probably do not play a significant role under practical conditions. Heterotrophic nitrification may be of relevance only when the wastewater contains a high COD/N ratio (>10). Anaerobic ammonium oxidation can occur in fully autotrophic systems with very long sludge retention times or biofilm systems. This conversion offers great opportunities since it allows us to denitrify with ammonium as electron donor, i.e. no organic substrate is needed in the nitrogen removal process.

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