Removal of Nitrate Nitrogen by Rhodotorula graminis Immobilized in Alginate Gel for Groundwater Treatment

Groundwater is the source of all tap water in Kumamoto City, Japan. However, the concentration of nitrate nitrogen (NO3−-N) tends to increase every year due to the influences of overfertilization, field disposal of livestock manure, and inflow of domestic wastewater. A heterotrophic nitrification–aerobic denitrification (HN-AD) system is an attractive approach for nitrate-nitrogen removal. In this study, Rhodotorula graminis NBRC0190, a naturally occurring red yeast that shows high nitrogen removal performance in glucose, was immobilized on calcium alginate hydrogel beads. NO3−-N removal efficiency exceeded 98% in the region of NO3−-N concentration below 10 mg/L in the model groundwater. Even after the same treatment was repeated five times, the denitrification performance of the R. gra immobilized alginate hydrogel beads was maintained. Finally, when this treatment method was applied to actual groundwater in Kumamoto City, it was possible to make the water of even higher quality.

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Factors affecting nitrogen removal from domestic wastewater using immobilized bacteria

Water Science & Technology ◽

10.2166/wst.1998.0047 ◽

1998 ◽

Vol 38 (1) ◽

pp. 193-202 ◽

Cited By ~ 5

Author(s):

Vasanthadevi Aravinthan ◽

Satoshi Takizawa ◽

Kenji Fujita ◽

Kazuya Komatsu

Keyword(s):

Activated Sludge ◽

Nitrogen Removal ◽

Nitrate Nitrogen ◽

Domestic Wastewater ◽

Nitrification Rate ◽

Factors Affecting ◽

Immobilized Bacteria ◽

Bulk Oxygen ◽

Micro Organisms ◽

Nitrogen Loadings

The parameters affecting the nitrogen removal process by the immobilized bacteria in the anoxic-oxic process have been studied by investigating two bench scale Runs A and B. The hollow polypropylene pellets have been dosed into the anoxic reactor in Run A and into the oxic reactors of both Runs up to 24% of volume. Run B was operated with no pellets in the anoxic reactor as a control. The maximum nitrification rate of 0.4 kg NH4-N/m3d was achieved in sufficient DO (6.5 mg/l) at 15°C in the reactor with both activated sludge and immobilized micro-organisms. The volumetric nitrification rate was found to be greatly dependent on bulk oxygen concentration especially when the DO was maintained below 4 mg/l. A mathematical model developed successfully simulated the experimental results showing the variation of nitrification rate with DO. In the case of denitrification, the contribution of immobilized bacteria was prominent when lesser concentration of MLSS was present in the activated sludge in the combined immobilized and activated sludge system. The presence of immobilized bacteria in the anoxic reactor will be effective when higher nitrate nitrogen loadings are expected and the maintenance of higher MLSS than 2 g/l in an activated sludge facility is not feasible.

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

Applied Sciences ◽

10.3390/app9091937 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1937 ◽

Cited By ~ 5

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.

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The Nitrogen-Removal Efficiency of a Novel High-Efficiency Salt-Tolerant Aerobic Denitrifier, Halomonas Alkaliphile HRL-9, Isolated from a Seawater Biofilter

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16224451 ◽

2019 ◽

Vol 16 (22) ◽

pp. 4451 ◽

Cited By ~ 1

Author(s):

Jilong Ren ◽

Chenzheng Wei ◽

Hongjing Ma ◽

Mingyun Dai ◽

Jize Fan ◽

...

Keyword(s):

Removal Efficiency ◽

Nitrogen Removal ◽

Nitrogen Balance ◽

High Efficiency ◽

Aerobic Denitrification ◽

Salt Tolerant ◽

N Accumulation ◽

Recirculating Aquaculture ◽

N Removal ◽

Recirculating Aquaculture Systems

Aerobic denitrification microbes have great potential to solve the problem of NO3−-N accumulation in industrialized recirculating aquaculture systems (RASs). A novel salt-tolerant aerobic denitrifier was isolated from a marine recirculating aquaculture system (RAS) and identified as Halomonas alkaliphile HRL-9. Its aerobic denitrification performance in different dissolved oxygen concentrations, temperatures, and C/N ratios was studied. Investigations into nitrogen balance and nitrate reductase genes (napA and narG) were also carried out. The results showed that the optimal conditions for nitrate removal were temperature of 30 °C, a shaking speed of 150 rpm, and a C/N ratio of 10. For nitrate nitrogen (NO3−-N) (initial concentration 101.8 mg·L−1), the sole nitrogen source of the growth of HRL-9, the maximum NO3−-N removal efficiency reached 98.0% after 24 h and the maximum total nitrogen removal efficiency was 77.3% after 48 h. Nitrogen balance analysis showed that 21.7% of NO3−-N was converted into intracellular nitrogen, 3.3% of NO3−-N was converted into other nitrification products (i.e., nitrous nitrogen, ammonium nitrogen, and organic nitrogen), and 74.5% of NO3−-N might be converted to gaseous products. The identification of functional genes confirmed the existence of the napA gene in strain HRL-9, but no narG gene was found. These results confirm that the aerobic denitrification strain, Halomonas alkaliphile HRL-9, which has excellent aerobic denitrification abilities, can also help us understand the microbiological mechanism and transformation pathway of aerobic denitrification in RASs.

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Isolation and Characteristics of Heterotrophic Nitrification-Aerobic Denitrification Bacterium, Bacillus cereus X7 at High Salinity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.111 ◽

2013 ◽

Vol 864-867 ◽

pp. 111-114 ◽

Cited By ~ 2

Author(s):

Ru Lei Yao ◽

Li Na Qiu ◽

Wei Wei Zhang ◽

Ai Jun Gong ◽

Zi Yu Wang ◽

...

Keyword(s):

Bacillus Cereus ◽

Nitrogen Removal ◽

High Salinity ◽

Removal Rate ◽

Aerobic Denitrification ◽

16S Rdna Sequence ◽

16S Rdna Sequence Analysis ◽

N Removal ◽

Nacl Concentration ◽

Biological Nitrogen

Biological nitrogen removal has been focused on in wastewater treatment field recently. A strain X7 was isolated from the sediment of pickle foodstuff wastewater. Based on its 16S rDNA sequence analysis, X7 was identified as Bacillus cereus. At NaCl concentration of 20 g/L, NH4+-N removal rate achieved 99.18%, when NO2--N and NO3--N removal rates were 77.24% and 68.6%, respectively. When NaCl concentration ranged from 0 to 40 g/L, the removal rate of NH4+-N was more than 97.59%. Therefore, due to the high nitrogen removal rate and excellent salt tolerance, Bacillus cereus X7 had a broad application prospect in the biodenitrification of brine wastewater.

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Biochar enhanced the nitrogen removal performance of heterotrophic nitrification-aerobic denitrification strain pseudomonas fluorescent sp. Z03 for insufficient carbon source wastewater under low temperature

10.21203/rs.3.rs-916848/v1 ◽

2021 ◽

Author(s):

Jie Jiang ◽

XiaoyanXu ◽

Zhina Guo ◽

Lianglun Sun ◽

Meizhen Tang

Keyword(s):

Electron Transfer ◽

Low Temperature ◽

Carbon Source ◽

Nitrogen Removal ◽

Removal Rate ◽

Heterotrophic Nitrification ◽

Redox Activity ◽

Aerobic Denitrification ◽

Control Group ◽

N Removal

Abstract In this study, biochar BC400 and BC700 were prepared, characterized and coupled with heterotrophic nitrification-aerobic denitrification (HNAD) strain Z03 for nitrogen removal experiments. The characterization results showed that BC700 has a higher specific surface area and a more complex multilayered pore structure, with increased aromatic condensation and higher crystallinity. BC400 and BC700 both have good redox activity, while BC400 has stronger electron donor capacities and BC700 owns better electron transfer properties. In addition, both BC400 and BC700 contain relatively high levels of dissolved organic carbon (DOC), reaching at 62.95 and 51.617mg/g respectively. BC400/BC700 coupled with strain Z03 can significantly improve the NH4+-N removal performance of low-temperature and low C/N wastewater compared with the control group. At a dosage of 4.0 g/L, the removal rate of NH4+-N reached to 95.16% (BC400 + Z03) and 84.37% (BC700 + Z03) within 72h, respectively. Higher than the sum of adsorption by BC400/BC700 (16.19%/18.85%) and microbial degradation (41.03%). Besides, the BC400 + BC700 + Z03 NH4+-N removal systems provide higher nitrogen removal efficiencies than BC400/BC700 + Z03 nitrogen removal systems. When the dosage (BC400 + BC700, mass ratio 5:1) reaches 3.0g/L, it can achieve more than 90% NH4+-N removal rate within 48h. The reasons for the promotion of biochar on microbial denitrification were analyzed as follows: 1) DOC can provide an additional carbon source for microorganisms; 2) biochar, as a pH buffer, can neutralize the acidity due to nitrification; 3) BC400 and BC700, as materials with good redox activity, may play a role in promoting the activity of electron transfer system and enzyme activity.

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