scholarly journals Heterotrophic Nitrification-Aerobic Denitrification Performance of Strain Y-12 under Low Temperature and High Concentration of Inorganic Nitrogen Conditions

Water ◽  
2017 ◽  
Vol 9 (11) ◽  
pp. 835 ◽  
Author(s):  
Qing Ye ◽  
Kaili Li ◽  
Zhenlun Li ◽  
Yi Xu ◽  
Tengxia He ◽  
...  
2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yi Xu ◽  
Tengxia He ◽  
Zhenlun Li ◽  
Qing Ye ◽  
Yanli Chen ◽  
...  

The cold-adapted bacterium Pseudomonas putida Y-9 was investigated and exhibited excellent capability for nitrogen removal at 15°C. The strain capable of heterotrophic nitrification and aerobic denitrification could efficiently remove ammonium, nitrate, and nitrite at an average removal rate of 2.85 mg, 1.60 mg, and 1.83 mg NL−1 h−1, respectively. Strain Y-9 performed nitrification in preference to denitrification when ammonium and nitrate or ammonium and nitrite coexisted in the solution. Meantime, the presence of nitrate had no effect on the ammonium removal rate of strain Y-9, and yet the presence of high concentration of nitrite would inhibit the cell growth and decrease the nitrification rate. The experimental results indicate that P. putida Y-9 has potential application for the treatment of wastewater containing high concentrations of ammonium along with its oxidation products at low temperature.


2021 ◽  
Author(s):  
Jie Jiang ◽  
XiaoyanXu ◽  
Zhina Guo ◽  
Lianglun Sun ◽  
Meizhen Tang

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.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1701
Author(s):  
Tengxia He ◽  
Deti Xie ◽  
Jiupai Ni ◽  
Zhu Li ◽  
Zhenlun Li

The aim of this study was to investigate the possibility of a simultaneous nitrification–denitrification hypothermic bacterium for applying in Cd(II), Co(II), and Mn(II)-contaminated wastewater. The influence of Cd(II), Co(II), and Mn(II) on the inorganic nitrogen removal capacity of the hypothermia bacterium Arthrobacter arilaitensis Y-10 was determined. The experimental results demonstrated that low concentration of Cd(II) (2.5 mg/L) exhibited no significant impact on bioremediation of ammonium. The nitrate and nitrite removal activities of strain Y-10 were enhanced by 0.1 and 0.25 mg/L of Cd(II), but hindered by more than 0.25 and 0.5 mg/L of Cd(II), respectively. However, the cell growth and denitrification activity ceased immediately once Co(II) was supplemented. In terms of Mn(II), no conspicuous inhibitory impact on ammonium bioremediation was observed even if Mn(II) concentration reached as high as 30 mg/L. The bioremediation of nitrates and nitrites was significantly improved by 0.5 mg/L of Mn(II), and then dropped sharply along with the increase of Mn(II). The order of the degree of inhibitory influence of the three heavy metal ions on the nitrogen bioremediation ability of strain Y-10 was Co(II) > Cd(II) > Mn(II). All the results highlighted that the heterotrophic nitrification was less sensitive to the inhibitory effects of Cd(II), Co(II), and Mn(II) relative to aerobic denitrification.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.


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