Sliding mode control of dissolved oxygen in an integrated nitrogen removal process in a sequencing batch reactor (SBR)

2009 ◽  
Vol 60 (10) ◽  
pp. 2545-2553 ◽  
Author(s):  
C. Muñoz ◽  
H. Young ◽  
C. Antileo ◽  
C. Bornhardt
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Sliding Mode ◽  
Batch Reactor ◽  
Pi Controller ◽  
Computational Point ◽  
Removal Process ◽  
Wide Range ◽  
Auto Tuning

This paper presents a sliding mode controller (SMC) for dissolved oxygen (DO) in an integrated nitrogen removal process carried out in a suspended biomass sequencing batch reactor (SBR). The SMC performance was compared against an auto-tuning PI controller with parameters adjusted at the beginning of the batch cycle. A method for cancelling the slow DO sensor dynamics was implemented by using a first order model of the sensor. Tests in a lab-scale reactor showed that the SMC offers a better disturbance rejection capability than the auto-tuning PI controller, furthermore providing reasonable performance in a wide range of operation. Thus, SMC becomes an effective robust nonlinear tool to the DO control in this process, being also simple from a computational point of view, allowing its implementation in devices such as industrial programmable logic controllers (PLCs).

Biological nitrogen removal in SBR bypassing nitrate generation accomplished by chlorination and aeration time control

2004 ◽  
Vol 49 (5-6) ◽  
pp. 295-300 ◽  
Author(s):  
Y. Peng ◽  
X. Song ◽  
C. Peng ◽  
J. Li ◽  
Y. Chen
Keyword(s):  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Biological Nitrogen Removal ◽  
Nitrite Accumulation ◽  
Removal Process ◽  
Aeration Time ◽  
Time Control ◽  
The Cost ◽  
Biological Nitrogen

A novel control strategy for biological nitrogen removal with high nitrite built-up through chlorine dosage was studied. In the biological nitrogen removal process operated in a bench-scale sequencing batch reactor, dose of chlorine of 0.2 mg/l in the form of sodium hypochlorite was applied after the COD was depleted. The aerobic phase switched to an anoxic phase shortly after the ammonium was completely biotically oxidized. Nitrite accumulation was stably achieved which was attributed to the chlorination and the lag-time of nitrification. With the time control, stable 100% conversion of nitrite could also be sustained even under the absence of chlorine for at least 20 days. The nitrite oxidizer should have been killed rather than been suppressed in this study. For engineering applications, the advantages of the nitrification/denitrification via nitrite can compensate the cost of chlorine dosage. Combined with the aeration time control, it is feasible to apply chlorination in a biological nitrogen removal process in SBRs.

Estimation of oxygen transfer rate in sequencing batch reactor

1996 ◽  
Vol 34 (3-4) ◽  
pp. 413-420
Author(s):  
Y. C. Liao ◽  
D. J. Lee
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Oxygen Transfer Rate ◽  
Intermittent Aeration ◽  
Transient Effects ◽  
Operational Parameters ◽  
Transient Model

Transient model of oxygen transfer rate in a sequencing batch reactor is derived and solved numerically. The dissolved oxygen response under several conditions is analyzed. Effects of operational parameters and liquid bath height are studied. When with short, intermittent aeration periods, the transient effects on oxygen transfer rate may be substantial and should be taken into considerations. An example considering bioreaction is also given.

Excess nitrogen accumulation in activated sludge in sequencing batch reactor with a single-stage oxic process

2009 ◽  
Vol 59 (3) ◽  
pp. 573-582 ◽  
Author(s):  
Xiao-ming Li ◽  
Dong-bo Wang ◽  
Qi Yang ◽  
Wei Zheng ◽  
Jian-bin Cao ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Ph Value ◽  
Batch Reactor ◽  
Nitrogen Loss ◽  
Single Stage ◽  
Synthetic Wastewater ◽  
Nitrogen Accumulation ◽  
Excess Nitrogen

It was occasionally found that a significant nitrogen loss in solution under neutral pH value in a sequencing batch reactor with a single-stage oxic process using synthetic wastewater, and then further studies were to verify the phenomenon of nitrogen loss and to investigate the pathway of nitrogen removal. The result showed that good performance of nitrogen removal was obtained in system. 0–7.28 mg L−1 ammonia, 0.08–0.38 mg L−1 nitrite and 0.94–2.12 mg L−1 nitrate were determined in effluent, respectively, when 29.85–35.65 mg L−1 ammonia was feeding as the sole nitrogen source in influent. Furthermore, a substantial nitrogen loss in solution (95% of nitrogen influent) coupled with a little gaseous nitrogen increase in off-gas (7% of nitrogen influent) was determined during a typical aerobic phase. In addition, about 322 mg nitrogen accumulation (84% of nitrogen influent) was detected in activated sludge. Based on nitrogen mass balance calculation, the unaccounted nitrogen fraction and the ratio of nitrogen accumulation in sludge/nitrogen loss in solution were 14.6 mg (3.7% of nitrogen influent) and 0.89, respectively. The facts indicated that the essential pathway of nitrogen loss in solution in this study was excess nitrogen accumulation in activated sludge.

Enhanced aerobic granulation and nitrogen removal by the addition of zeolite powder in a sequencing batch reactor

2012 ◽  
Vol 97 (20) ◽  
pp. 9235-9243 ◽  
Author(s):  
Dong Wei ◽  
Xiaodong Xue ◽  
Shuwei Chen ◽  
Yongfang Zhang ◽  
Liangguo Yan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Aerobic Granulation
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