Effects of HRT on biological nitrogen removal in single-stage autotrophic process

2016 ◽  
Vol 1 (2) ◽  
pp. 18 ◽  
Author(s):  
Hong Liang ◽  
Shutong Liu ◽  
Xue Li ◽  
Xueying Sun ◽  
Dawen Gao

An external circulation Sequencing Batch Reactor (ecSBR) was used to study the efficiency of nitrogen removal by autotrophic microbe. With gradually reducing the dissolved oxygen (DO) concentration from 1.2 mg/L to 0.04 mg/L, the single-stage autotrophic biological nitrogen removal (sABNR) process could be operated stably. After removing the aeration, the process could still stay sABNR stably, and the concentration of NH4+-N was 0.9 mg/L in effluent, the rate of nitrate (produced)/NH4+-N (removed) was in the range of 0.12–0.40. The results showed that the concentration of NH4+-N in effluent was 0.8, 0.8 and 9.9 mg/L with the hydraulic retention time (HRT) at 8 h, 6 h and 4 h respectively, the removal efficiency of ammonia were 98.2%, 98.1% and 73.6% respectively. The rate of nitrate (produced)/NH4+-N (consumed) was 0.05 at HRT 6 h, and the nitrogen loading rate (NLR) and nitrogen removal rate (NRR) were 169.7 and 129.7 g/m3/d, the removal efficiency of total nitrogen (TN) was 77.5%. In conclusion the optimal HRT was 6 h instead of 8 h or 4 h enough for ammonia removal without causing energy wastage. 

2004 ◽  
Vol 50 (10) ◽  
pp. 45-50 ◽  
Author(s):  
N. Kishida ◽  
J.H. Kim ◽  
M. Chen ◽  
S. Tsuneda ◽  
H. Sasaki ◽  
...  

To establish an automatic control system of external carbon addition in biological nitrogen removal, a bench-scale sequencing batch reactor with real-time control strategy was designed in this study. An oxidation-reduction potential (ORP) profile was used for automatic control of external carbon addition. The mean removal efficiency of total organic carbon was over 98%. Complete denitrification in an anoxic phase and complete denitrification and nitrification in anoxic and oxic phases were accomplished, respectively, because the oxic and anoxic periods were also appropriately controlled with ORP and pH profiles, respectively. Mean removal efficiency of total nitrogen was over 95%. When concentration of influent wastewater was changed, volume of additional carbon was automatically changed with the influent fluctuation, and flexible hydraulic retention time was achieved in this system.


2016 ◽  
Vol 3 (4) ◽  
pp. 175-179 ◽  
Author(s):  
Nathan D. Manser ◽  
Meng Wang ◽  
Sarina J. Ergas ◽  
James R. Mihelcic ◽  
Arnold Mulder ◽  
...  

2013 ◽  
Vol 67 (12) ◽  
pp. 2677-2684 ◽  
Author(s):  
M. Christensson ◽  
S. Ekström ◽  
A. Andersson Chan ◽  
E. Le Vaillant ◽  
R. Lemaire

ANITA™ Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the ‘BioFarm concept’, has been developed in order to decrease the start-up time of new ANITA Mox installations. New ANITA Mox installations are started with typically 3–15% of the added carriers being from the ‘BioFarm’, with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjölunda wastewater treatment plant (WWTP) in Malmö, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m3 d and approximately 90% ammonia removal within 4 months from start-up. This first ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N2O emissions, <1% of the reduced nitrogen and a very stable and robust process towards variations in loads and process conditions. The second ANITA Mox plant, started up at Sundets WWTP in Växjö, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.


2010 ◽  
Vol 61 (3) ◽  
pp. 671-676 ◽  
Author(s):  
W. Chen ◽  
F. Y. Sun ◽  
X. M. Wang ◽  
X. Y. Li

A hybrid system has been developed for biological nitrogen removal through nitrification-denitrification. The system includes an aerobic tank and an anoxic tank with an intermediate sludge settler connected to a membrane bioreactor (MBR) with a submerged 0.4 μm hollow-fiber membrane module. The laboratory system has a total working volume of 6.5 L treating a glucose-based synthetic wastewater. The experimental results demonstrate that the new process is highly effective for simultaneous organic and nitrogen removal. During the stationary operation, a sludge SS (suspended solids) concentration of 6 g/L or higher can be maintained in the reactors. The system has a COD (chemical oxygen demand) loading rate of up to 2,100 mg/L-d and a total nitrogen loading rate of up to 170 mg N/L-d. More than 95% COD can be degraded, and the total nitrogen removal efficiency can be 90% or higher as the nitrogen is reduced from 100 to around 7.5 mg/L. A high quality effluent is produced with a SS of less than 1 mg/L. With the MBR, organic degradation, nitrogen removal and sludge-liquid separation can be well achieved within a short HRT of about 10 hr.


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