Simultaneous nitrification and denitrification without nitrite accumulation by a novel isolated Ochrobactrum anthropic LJ81

2019 ◽  
Vol 272 ◽  
pp. 442-450 ◽  
Author(s):  
Xin Lei ◽  
Yating Jia ◽  
Yuancai Chen ◽  
Yongyou Hu
2012 ◽  
Vol 610-613 ◽  
pp. 2047-2052
Author(s):  
Jin Xiang Fu ◽  
Xin Chun Zhang ◽  
Peng Fei Yu

This paper studies the impact of cooling and warming on shortcut and simultaneous nitrification and denitrification under low temperature. The results show that the effluent concentration of NH4+-N and TN gradually increased, the nitrite accumulation rate decreased when DO was 0.3~0.5 mg•L-1, sludge return ratio was 300%, PH was 7.5~8.5, temperature dropped from 15 °Cto 8°C. From 10°C to 8°C in cooling, the average nitrite accumulation rate was 58.17% in A (HRT=24h) reactor. During the system heating process, treatment effect of the system gradually changed for the better. From 12°C to 15°Cin heating process, the average nitrite accumulation rate was 74.39% in B (HRT=48h) reactor. The system treatment effect in B reactor was better by contrasting A and B reactors, therefore, we can increase HRT to reduce the adverse effects on the system due to the temperature decreases to enhance TN removal effect of system.


2014 ◽  
Vol 69 (12) ◽  
pp. 2541-2547 ◽  
Author(s):  
Yingyan Yan ◽  
Ping Li ◽  
Jinhua Wu ◽  
Nengwu Zhu ◽  
Pingxiao Wu ◽  
...  

A sequencing batch airlift reactor was used to investigate the characteristics of nitrous oxide (N2O) emission and the succession of an ammonia-oxidizing bacteria (AOB) community. The bioreactor could successfully switch from the complete simultaneous nitrification and denitrification (SND) process to the short-cut SND process by increasing the influent pH from 7.0–7.3 to 8.0–8.3. The results obtained showed that, compared with the complete SND process, the TN removal rate and SND efficiency were improved in the short-cut SND process by approximately 13 and 11%, respectively, while the amount of N2O emission was nearly three times larger than that in the complete SND process. The N2O emission was closely associated to nitrite accumulation. Analysis of the AOB microbial community showed that nitrifier denitrification by Nitrosomonas-like AOB could be an important pathway for the enhancement of N2O emission in the short-cut SND process.


2013 ◽  
Vol 777 ◽  
pp. 232-237 ◽  
Author(s):  
Hui Wei Zhao ◽  
Ke Fang Zhang ◽  
Hong Wei Rong ◽  
Chao Sheng Zhang ◽  
Zhi Wen Yang

This study aimed to evaluate the effect of carbon nitrogen ratio (COD/N) on simultaneous nitrification and denitrification (SND) via nitrite technology in SBBR and the process control. Under the condition of different C/N ratios respectively 1.8, 3.6, 7,5,11.1 and 13.7, the various indices of the removal efficiency in the system and DO, ORP, and pH in the process of reaction were investigated. The C/N ratio was found to be an important limiting factor for SBBR simultaneous nitrification and denitrification via nitrite process. After integrating the factor of energy consumption and removal efficiency, we obtained that the optimum C/N ratios control range from 7.5 to 11.1, reaction time was between 225 min and 315 min, nitrite accumulation rate was between 72.83 % and 78.7 %, COD removal rate was between 92.31 % and 93.08 %, the total nitrogen removal rate was between 81.0 % and 85.86 %. For steady-state simultaneous nitrification and denitrification via nitrite process in SBBR, the jump point (C) on the DO, pH and ORP curve at reaction later period can be used as a control point to indicate the end of the reaction.


2013 ◽  
Vol 39 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Katarzyna Bernat

Abstract In this study, the dependence between volumetric exchange rate (n) in an SBR (Sequencing Batch Reactor) with a modified cycle and simultaneous nitrification and denitrification (SND) efficiency during the treatment of anaerobic sludge digester supernatant was determined. In the SBR cycle alternating three aeration phases (with limited dissolved oxygen (DO) concentration up to 0.7 mg O2/L) and two mixing phases were applied. The lengths of each aeration and mixing phases were 4 and 5.5 h, respectively. Independently of n, a total removal of ammonium was achieved. However, at n = 0.1 d-1 and n = 0.3 d-1 nitrates were the main product of nitrification, while at n = 0.5 d-1, both nitrates and nitrites occurred in the effluent. Under these operational conditions, despite low COD/N (ca. 4) ratio in the influent, denitrification in activated sludge was observed. A higher denitrification efficiency at n = 0.5 d-1 (51.3%) than at n = 0.1 d-1 (7.8%) indicated that n was a crucial factor influencing SND via nitrite and nitrate in the SBR with a low oxygen concentration in aeration phases.


1994 ◽  
Vol 29 (10-11) ◽  
pp. 409-416 ◽  
Author(s):  
F. Çeçen ◽  
I. E. Gönenç

The kinetics of nitrogen removal was studied in upflow submerged nitrification and denitrification filters in series. Nitrification followed first-, half-, and zero-order kinetics. For the half-order range the half-order rate constant was about 0.9gNH4-N1/2m−1/2d−1. The zero-order rate constants for the DO ranges of 2-3 mg/L and 4-5 mg/L were found as 0.47 gNH4-Nm−2d−1 and 1.82 gNH4-Nm−2d−1, respectively. In the zero-order region ammonia removal proceeded as a half-order reaction in oxygen concentration and the half-order rate constants were about 1.4-2.7 gO21/2m−1/2d−1. Nitrite accumulation reached a considerable degree at bulk oxygen to bulk ammonia ratios lower than 5 since the formation of nitrate was inhibited. Similar to nitrification half- and zero-order kinetic regions were also observed in denitrification. The half- and zero-order rate constants for carbon unlimited cases (influent COD/NOx-N>5) were about 0.23 gNOx-N1/2m−1/2d−1 and 1.9 gNOx-Nm−2d−1, respectively. The nitrite produced in the nitrification stage could be reduced in denitrification. The removal kinetics in the presence of nitrite was found to be similar to the kinetics when the influent consisted of nitrate only.


2001 ◽  
Vol 43 (1) ◽  
pp. 269-276 ◽  
Author(s):  
N. Puznava ◽  
M. Payraudeau ◽  
D. Thornberg

The aim of this article is to present a new biological aerated filter (BAF) for nitrogen removal based on simultaneous nitrification and denitrification. Contrary to the systems which integrate both an aerated and a non-aerated zone to allow complete nitrogen removal in one compact or two different units (pre-denitrification and nitrification), this upflow BAF system is based on the principle of simultaneous nitrification and denitrification since the filter is completely aerated. The denitrification process is possible due to the diffusion effect which dominates biofilm processes. The real time aeration control allows us to maintain a low dissolved oxygen value (0.5 to 3 mg O2/l). In this case, the biofilm will not be fully (or less) penetrated with oxygen and denitrification will be carried out in a large part of the biofilm. Therefore, nitrification and denitrification is running simultaneously in different depths of the biofilm. By using 50% less air this BAF gave the same results (less than 20mg TN/l) on pilot plant as a classical nitrification and denitrification BAF (Toettrup et al., 1994). Less recirculation was necessary to achieve the same denitrification.


2021 ◽  
Author(s):  
Aline dos Reis Souza ◽  
Mateus Pimentel de Matos ◽  
Luciene Alves Batista Siniscalchi ◽  
Ronaldo Fia

Abstract The objective of this study was to evaluate the effect of the introduction of a complementary aerobic treatment composed of a submerged aerated biological filter (SABF) with a secondary clarifier (SC), followed by horizontal subsurface flow constructed wetlands (CWs), after anaerobic units, on the ability to remove pollutants in different aeration phases (Ph1, Ph2, and Ph3) at the effluent treatment station of the Parque Francisco de Assis (PFA) dog shelter. Ph1 and Ph2 had 7 and 5 hours of daily aeration, respectively, and Ph3 had intermittent aeration every 2 hours. The phases were monitored regarding the removal efficiency of organic matter, solids, nutrients (N, P), coliforms, and detection of Giardia and Cryptosporidium. It was found that post-treatment provided greater removal efficiencies and that the aeration strategy of Ph3 showed mean efficiencies of 71% for COD removal and 77% for BOD removal, being similar or statistically higher, even with less biodegradable effluent, than those of Ph1 and Ph2. The SABF and SC removed N by nitrification and denitrification, leaving a total Kjeldahl nitrogen (TKN) concentration in the effluent of 18 mg L−1. The CW showed potential for simultaneous nitrification and denitrification (SND), in addition to solid filtration. The system did not satisfactorily remove thermotolerant coliforms (ThermC) (1 ± 0 log). PCR suggested the presence of the pathogens Giardia and Cryptosporidium in all post-treatment units in Ph1 and Ph2.


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