Intensified nitrogen removal by heterotrophic nitrification aerobic denitrification bacteria in two pilot-scale tidal flow constructed wetlands: Influence of influent C/N ratios and tidal strategies

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.

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Comment on “Enhanced Long-Term Nitrogen Removal and Its Quantitative Molecular Mechanism in Tidal Flow Constructed Wetlands”

Environmental Science & Technology ◽

10.1021/acs.est.5b03258 ◽

2015 ◽

Vol 49 (18) ◽

pp. 11241-11242 ◽

Cited By ~ 6

Author(s):

Yi Chen ◽

Jan Vymazal

Keyword(s):

Molecular Mechanism ◽

Constructed Wetlands ◽

Nitrogen Removal ◽

Tidal Flow

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Effect of the Influent Substrate Concentration on Nitrogen Removal from Summer to Winter in Field Pilot-Scale Multistage Constructed Wetland–Pond Systems for Treating Low-C/N River Water

Sustainability ◽

10.3390/su132212456 ◽

2021 ◽

Vol 13 (22) ◽

pp. 12456

Author(s):

Tao Wang ◽

Liping Xiao ◽

Hongbin Lu ◽

Shaoyong Lu ◽

Xiaoliang Zhao ◽

...

Keyword(s):

River Water ◽

Constructed Wetlands ◽

Nitrogen Removal ◽

Constructed Wetland ◽

Substrate Concentration ◽

Removal Rate ◽

Carbon Sources ◽

River Estuary ◽

Pilot Scale ◽

Surface Flow

The quality of micropolluted water is unstable and its substrate concentration fluctuates greatly. The goal is to predict the concentration effect on the treatment of nitrogen in a river with an actual low C/N ratio for the proposed full-scale Xiaoyi River estuary wetland, so that the wetland project can operate stably and perform the water purification function effectively in the long term. Two pilot-scale multistage constructed wetland–pond (MCWP) systems (S1 and S2, respectively) based on actual engineering with the same “front ecological oxidation ponds, two-stage horizontal subsurface flow constructed wetlands and surface flow constructed wetlands (SFCWs) as the core and postsubmerged plant ponds” as the planned process were constructed to investigate the effect of different influent permanganate indexes (CODMn) and total nitrogen (TN) contents on nitrogen removal from micropolluted river water with a fixed C/N ratio from summer to winter in the field. The results indicate that the TN removal rate in the S1 and S2 systems was significant (19.56% and 34.84%, respectively). During the process of treating this micropolluted water with a fixed C/N ratio, the influent of S2 with a higher CODMn concentration was conducive to the removal of TN. The TN removal rate in S2 was significantly affected by the daily highest temperature. There was significant nitrogen removal efficiency in the SFCWs. The C/N ratio was a major determinant influencing the nitrogen removal rate in the SFCWs. The organic matter release phenomenon in SFCWs with high-density planting played an essential role in alleviating the lack of carbon sources in the influent. This research strongly supports the rule that there is seasonal nitrogen removal in the MCWPs under different influent substrate concentrations, which is of guiding significance for practical engineering.

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Microbiological conversions in nitrogen removal

Water Science & Technology ◽

10.2166/wst.1998.0002 ◽

1998 ◽

Vol 38 (1) ◽

pp. 1-7 ◽

Cited By ~ 53

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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