Simultaneous nitrification and denitrification in a single reactor using bio-electrochemical process

2002 ◽  
Vol 46 (4-5) ◽  
pp. 163-169 ◽  
Author(s):  
T. Watanabe ◽  
S. Hashimoto ◽  
M. Kuroda
Keyword(s):  
Electric Current ◽  
Fixed Effects ◽  
Removal Rate ◽  
Electrochemical Process ◽  
Hydrogen Gas ◽  
High Rate ◽  
Bulk Solution ◽  
Simultaneous Nitrification And Denitrification ◽  
Do Concentration ◽  
Nitrification And Denitrification

Feasibility of a bio-electrochemical process for simultaneous nitrification and denitrification in a single reactor was experimentally investigated. The reactor consisted of anodic and cathodic electrodes, on which nitrifying and denitrifying biofilms, respectively, were fixed. Effects of the applied electric current and DO concentration in the bulk solution were examined. The TN removal could be achieved through the occurrence of nitrification and denitrification in anodic and cathodic biofilms, respectively. Both nitrification and denitrification rates increased with an increase in the applied electric current. Even at low DO concentration in the bulk solution, nitrification proceeded at a high rate by utilizing oxygen generated on the anode. Denitrification rate remained relatively high at high DO concentration due to supplying hydrogen gas to the inner side of the cathodic biofilm. The higher TN removal rate tended to be obtained at lower DO concentration and higher current density. From these results, it was concluded that the bio-electrochemical process was applicable to simultaneous nitrification and denitrification due to stable formation of aerobic and anoxic regions in the single reactor.

scholarly journals A New Developed Airlift Reactor Integrated Settling Process and Its Application for Simultaneous Nitrification and Denitrification Nitrogen Removal

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Tao Zhang ◽  
Chaohai Wei
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Airlift Reactor ◽  
Simultaneous Nitrification And Denitrification ◽  
Concentration Difference ◽  
Do Concentration ◽  
Nitrification And Denitrification ◽  
Sludge Settling

This study presented the performance of simultaneous nitrification and denitrification (SND) process using a new developed hybrid airlift reactor which integrated the activated sludge reaction process in the airlift reactor and the sludge settling separation process in the clarifier. The proposed reactor was started up successfully after 76 days within which the COD and total nitrogen removal rate can reach over 90% and 76.3%, respectively. The effects of different COD/N and DO concentrations on the performance of reactor were investigated. It was found that the influent COD/N maintained at 10 was sufficient for SND and the optimum DO concentration for SND was in the range of 0.5 to 0.8 mg L−1. Batch test demonstrated that both macroscopic environment caused by the spatial DO concentration difference and microscopic environment caused by the stratification of activated sludge may be responsible for the SND process in the reactor. The hybrid airlift reactor can accomplish SND process in a single reactor and in situ automatic separation of sludge; therefore, it may serve as a promising reactor in COD and nitrogen removal fields.

scholarly journals Simultaneous Nitrification and Denitrification in an SBR with a Modified Cycle During Reject Water Treatment

2013 ◽  
Vol 39 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Katarzyna Bernat
Keyword(s):  
Batch Reactor ◽  
Anaerobic Sludge ◽  
Simultaneous Nitrification And Denitrification ◽  
Low Oxygen ◽  
Total Removal ◽  
Operational Conditions ◽  
Reject Water ◽  
Do Concentration ◽  
Nitrification And Denitrification ◽  
Low Oxygen Concentration

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.

Nitrogen removal in a fluidized bed bioreactor by using mixed culture under oxygen-limited conditions

2004 ◽  
Vol 50 (6) ◽  
pp. 313-320 ◽  
Author(s):  
T. Khin ◽  
A.P. Annachhatre
Keyword(s):  
Fluidized Bed ◽  
Mixed Culture ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Flow Rates ◽  
Fluidized Bed Bioreactor ◽  
Oxygen Gas ◽  
Do Concentration ◽  
Total Nitrogen Removal ◽  
Nitrification And Denitrification

Nitrogen removal involving nitrification and denitrification was investigated in a fluidized bed bioreactor by using mixed culture sludge under oxygen-limited conditions. Methane was used as a sole carbon source for denitrification. In this study, optimal nitrification and denitrification rates were examined by varying methane and oxygen gas dissolution flow rates, 90 ml/min, 400 ml/min and 650 ml/min, in each. Simultaneously nitrification and denitrification was achieved. The total nitrogen removal rate was 15-mg N/g VSS. d, 21-mg N/g VSS. d and 26.4-mg N/g VSS. d at gas dissolution flow rate 90 ml/min, 400 ml/min and 650 ml/min, respectively. No significant accumulation of nitrite was found in this experiment. Nitrogen removal rates depend on gas dissolution flow rates. DO concentration was at 0.5Ð2 mg/L.

Effect of Sludge Loading on the Simultaneous Nitrification and Denitrification by Using a Sequencing Batch Bioreactor

2011 ◽  
Vol 183-185 ◽  
pp. 231-235
Author(s):  
Yan Ping Jia ◽  
Lan He Zhang ◽  
Zhi Ling Zhao ◽  
Tao Yang
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Idle Time ◽  
Synthetic Wastewater ◽  
Simultaneous Nitrification And Denitrification ◽  
Aeration Time ◽  
Batch Bioreactor ◽  
Do Concentration ◽  
Nitrification And Denitrification

In this study, a sequencing batch reactor (SBR) was used to treat synthetic wastewater when dissolved oxygen (DO) concentration and temperature were 0.5-1.0mg/L and 30±1°C, respectively. Effect of sludge loading(Ns) on simultaneous nitrification and denitrification (SND) was investigated. The results indicated that removal efficiencies of ammonia nitrogen (NH4+-N), COD and total nitrogen (TN) were all higher than 90%, respectively, when influent NH4+-N and Ns were 35-45mg/L, 0.15kgCOD/(kgMLSS•d) under 7 hours of aeration time and 1 hour of idle time, respectively. Therefore, the SBR has obviously achieved simultaneous nitrification and denitrification.

Simultaneous Nitrification and Denitrification in Biofilm-Electrode Reactor

2013 ◽  
Vol 652-654 ◽  
pp. 1633-1636 ◽  
Author(s):  
Xiao Liu ◽  
Mei Yang ◽  
Xian Huai Huang
Keyword(s):  
Dissolved Oxygen ◽  
Electric Current ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Simultaneous Nitrification And Denitrification ◽  
Autotrophic Denitrification ◽  
Effluent Recirculation ◽  
Removal Efficiencies ◽  
Nitrification And Denitrification ◽  
Limited Oxygen

To study the nitrification and denitrification in compartmented biofilm-electrode reactor (C-BER) under limited oxygen, influence of mild electrolysis on nitrogen removal was investigated under low C/N (mole ratios) with dissolved oxygen about 1mg/ L. It was found that nitrogen removal was mainly through simultaneous nitrification and denitrification (SND). C/N ratio was 1, average total nitrogen (TN) removal efficiencies were 33% and 45% for electric current of 5 and 15mA. C/N was 0.5, electric current was 25mA and effluent was recirculated, TN removal efficiency increased to 60%, within which autotrophic denitrification accounted for about 51%. There was about 50% NH3-N reduced under 15mA when C/N ratio was 1, this increased to 70% for 25mA when C/N ratio was 0.5. Nevertheless, TN reduced between anode and cathodes accounted for 64% in all. The experimental results show that both higher electric current and effluent recirculation are good for SND process under oxygen-limited condition, nitrogen removal can be activated by mild electrolysis.

The Realization of Nitrification and Denitrification Processes in Low C/N Sewage

2011 ◽  
Vol 233-235 ◽  
pp. 600-603
Author(s):  
Gao Shun Qiu ◽  
Ling Feng Qiu ◽  
Yi Ming Chen
Keyword(s):  
Inflection Point ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Ph Value ◽  
Removal Rate ◽  
Batch Reactor ◽  
Mixing Time ◽  
Simultaneous Nitrification And Denitrification ◽  
Nitrification And Denitrification

The influences of HRT, C/N ratio on simultaneous nitrification and denitrification (SND) and the rule of pH in a sequencing batch reactor (SBR) were investigated while treating low C/N synthetic municipal wastewater. The results showed that the function of SND became more outstanding and the removal rate of TN, NH4+-N was improved greatly by lengthening HRT appropriately; when the C/N increased, the denitrification effect of the simultaneous nitrification and denitrification would be improved; .At the same time, the variation of pH value was well related to ammonia oxidation. So that judgment on the ending of nitrification and denitrification could be based on the inflection point on the varied curve of pH, and thus reducing aeration and mixing time for the purpose of energy saving.

N2O emission in short-cut simultaneous nitrification and denitrification process: dynamic emission characteristics and succession of ammonia-oxidizing bacteria

2014 ◽  
Vol 69 (12) ◽  
pp. 2541-2547 ◽  
Author(s):  
Yingyan Yan ◽  
Ping Li ◽  
Jinhua Wu ◽  
Nengwu Zhu ◽  
Pingxiao Wu ◽  
...  
Keyword(s):  
Removal Rate ◽  
N2o Emission ◽  
Nitrite Accumulation ◽  
Ammonia Oxidizing Bacteria ◽  
Simultaneous Nitrification And Denitrification ◽  
Process Dynamic ◽  
Nitrifier Denitrification ◽  
Important Pathway ◽  
Nitrification And Denitrification ◽  
Denitrification Process

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.

Study the Effects of Environmental Factors on Simultaneous Nitrification and Denitrification in SBBR

2010 ◽  
Vol 113-116 ◽  
pp. 904-907
Author(s):  
Ya Feng Li ◽  
Ying Hao ◽  
Jing Bo Yao ◽  
Ting Zhang
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Biofilm Reactor ◽  
Simultaneous Nitrification And Denitrification ◽  
Municipal Wastewater Treatment ◽  
Sequencing Batch Biofilm Reactor ◽  
Nitrification And Denitrification ◽  
Micro Organisms

The experiment studies the phenomenon of simultaneous nitrification and denitrification (SND) in SBBR filled with polyurethane as micro-organisms immobilized carriers. Polyurethane fills in SBR as micro-organisms immobilized carriers, formation of a Sequencing Batch Biofilm Reactor (SBBR). Under the anaerobic/aerobic conditions, we studied the effects of C/P, C/N and DO on SND. The results showed that when COD was 400mg/L, C/P was 43.2~50.2, C/N was 9.41~11.9 of the influent, the concentration of DO was 3.31~4.01mg/L, the effect of TN removal was good. When C/P was 46.9, C/N was 10.3, the concentration of DO was 3.58mg/L, the removal rate of TN was 83.71%, TN effluent was 6.45mg/L. TN effluent followed byⅠA standard of “Discharge standard of pollutants for municipal wastewater treatment plant”. DO concentrations impact the forms of nitrogen in the effluent. C/P, C/N and DO play an important role on SND in SBBR filled with polyurethane. Controlling these factors effectively can inhance the effect of nitrogen removal.

Effect of Carbon Nitrogen Ratio on Simultaneous Nitrification and Denitrification via Nitrite Technology in Sequencing Batch Biofilm Reactor and the Process Control

2013 ◽  
Vol 777 ◽  
pp. 232-237 ◽  
Author(s):  
Hui Wei Zhao ◽  
Ke Fang Zhang ◽  
Hong Wei Rong ◽  
Chao Sheng Zhang ◽  
Zhi Wen Yang
Keyword(s):  
Process Control ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Control Point ◽  
Biofilm Reactor ◽  
Nitrite Accumulation ◽  
Simultaneous Nitrification And Denitrification ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Nitrification And Denitrification

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.

Sign in / Sign up

Export Citation Format

Share Document