Effects of influent COD/N ratio and internal recycle ratio on nitrogen removal efficiency in the KNR process

2006 ◽  
Vol 53 (9) ◽  
pp. 265-270 ◽  
Author(s):  
C.W. Suh ◽  
S.H. Lee ◽  
H.S. Jeong ◽  
J.C. Kwon ◽  
H.S. Shin
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Denitrification Rate ◽  
Optimal Operating ◽  
Operating Condition ◽  
Optimal Operating Condition ◽  
External Carbon Source ◽  
Recycle Ratio ◽  
Removal Efficiencies

In this study, with the KNR® process that has many advantages, the nitrogen removal efficiency of KNR was experimentally investigated at various COD/N ratios of influent conditions. The optimal operating condition of internal recycle ratio was evaluated. The TN removal efficiencies were 59.1, 72.5 and 75.9% at the COD/N ratios of 3, 5 and 7, respectively. These high removal efficiencies resulted from high denitrification rate in UMBR with high microorganism concentration. Furthermore, specific endogenous denitrification at MLVSS of 10.3 g/L that is similar to MLVSS in UMBR was over two times higher than that at MLVSS of 2.06 g/L. This result suggests that endogenous denitrification rate in UMBR is so high that the requirement of an external carbon source can be saved. As the internal recycle ratio increased from 100 to 400%, the TN removal efficiency also improved from 69.5 to 82.9%, and the optimal internal recycle ratio was 300%.

Theoretical analysis and enhanced nitrogen removal performance of step-feed SBR

2008 ◽  
Vol 58 (4) ◽  
pp. 795-802 ◽  
Author(s):  
Jianhua Guo ◽  
Yongzhen Peng ◽  
Qing Yang ◽  
Shuying Wang ◽  
Ying Chen ◽  
...  
Keyword(s):  
Carbon Source ◽  
Theoretical Analysis ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
High Efficiency ◽  
Flow Mode ◽  
External Carbon Source ◽  
Influent Flow

To achieve high nitrification and denitrification rates, step-feed SBR with multiple aerobic and anoxic phases was adopted to study nitrogen removal performance. Theoretical analysis of step-feed SBR was presented first, from which feeding steps and C/N ratio had significant influences on nitrogen removal performance. Total nitrogen removal efficiency would increase with increasing of feeding steps, while the increasing extent was not distinct with feeding steps above 4. At a given feeding step, nitrogen removal efficiency would also increase with increasing of C/N ratio. Experimental work was conducted in a lab-scale SBR to investigate practical effects of these critical factors, using real municipal wastewater. The results showed when C/N ratio was appropriately decreasing influent flow mode could achieve enhanced nitrogen removal with less adding of external carbon source, compared with equal influent flow mode. Three-step equal influent flow mode was recommended to treat common municipal wastewater in view of operation complexity. Non steady-state experiments over about three months confirmed step-feed SBR was an enhanced nitrogen removal process with high efficiency. Total nitrogen in the effluent was under 2 mg/L, the average removal efficiency achieved for TN was over 97% just adding a little external carbon source, and good sludge settleability was obtained.

Enhancing denitrification efficiency for nitrogen removal using waste sludge alkaline fermentation liquid as external carbon source

2018 ◽  
Vol 26 (5) ◽  
pp. 4633-4644 ◽  
Author(s):  
Mengyu Shao ◽  
Liang Guo ◽  
Zonglian She ◽  
Mengchun Gao ◽  
Yangguo Zhao ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Waste Sludge ◽  
External Carbon Source ◽  
Fermentation Liquid

Advanced nitrogen removal via nitrite from municipal wastewater in a pilot-plant sequencing batch reactor

2009 ◽  
Vol 59 (12) ◽  
pp. 2371-2377 ◽  
Author(s):  
Q. Yang ◽  
X. H. Liu ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
H. W. Sun ◽  
...  
Keyword(s):  
Carbon Source ◽  
Process Control ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Pilot Plant ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Nitrite Accumulation ◽  
Advanced Nitrogen Removal

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.

Enhanced Nitrogen Removal of Low C/N Wastewater in a Subsequent Denitrifying Reactor Fed by Endogenous Carbon Source Generated from Primary Sludge Fermentation

2011 ◽  
Vol 281 ◽  
pp. 101-105
Author(s):  
Cheng Cheng Wu ◽  
Yong Zhen Peng ◽  
Liang Zhang ◽  
Shu Ying Wang
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
High Performance ◽  
Reduction Potential ◽  
Biological Nitrogen Removal ◽  
Primary Sludge ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Biological Nitrogen

A novel post-denitrification system fed by carbon source from primary sludge (PS) was used for enhancing biological nitrogen removal (BNR) of low C/N wastewater. This system included one anoxic/oxic (AO) reactor and a special reactor for simultaneous sludge fermentation and denitrification (Sifeden). Ammonia was nitrified to nitrate in AO and then the nitrate was reduced to dinitrogen in Sifeden , into which PS was added intermittently. Results showed that this system had high performance on nitrogen removal. Total nitrogen (TN) removal efficiency was higher than 85% and the effluent TN≤10mg/L in the condition of influent C/N≤2. In Sifeden, volatile fatty acid (VFA) produced from PS fermentation provided electron donor for nitrate reduction, and PS was preliminarily stabilized simultaneously. Oxidation-Reduction Potential (ORP) had a significant correlation with the denitrification performance. TN removal efficiency could be further improved if adopting proper PS addition strategy according to the ORP profiles.

scholarly journals Enhance nitrogen removal in bioretention cells with addition of hydrothermal pre-treated pine barks as external carbon source

2021 ◽  
Author(s):  
Jing Tuo ◽  
Shiwei Cao ◽  
Muzi Li ◽  
Rong Guo
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Common Factor ◽  
Nutrients Removal ◽  
Fiber Structure ◽  
Effluent Quality ◽  
External Carbon Source ◽  
Carbon Release ◽  
Cod Removal Rate

Abstract The problem of poor carbon source is a common factor limiting the nutrients removal in bioretention cells (BRCs). This study aimed to investigate the feasibility of using modified biomass in BRCs filled with a mixture of fly ash ceramsite and pumice fillers to enhance nitrogen removal. Different pretreatment methods (hydrothermal-treated, acid-treated and alkali-treated) were attempted, and hydrothermal pretreatment showed a best performance in carbon release ability. The scanning electron microscopy showed that the lignin in hydrothermal pretreated pine barks (H-PBs) was destroyed, and the fiber structure became thinner with more irregular folds, which improved the accessibility of cellulose and attachment of microorganisms. The addition of H-PBs significantly enhanced the nutrients removal in BRCs, and the removal rates of TN and NO3−-N increased by 23.25% and 38.22% compared with those in BRC-A (without external carbon source), but the removal rate of NH4+-N was inferior to BRC-A. Besides, the large carbon release amount of H-PBs did not deteriorate the effluent quality, with COD removal rate of 87.98% in the 48 d. These results indicate that the BRCs by adding H-PBs could intensify the denitrification process.

Equalization characteristics of an upflow sludge blanket – aerated biofilter (USB-AF) system

2005 ◽  
Vol 51 (10) ◽  
pp. 301-310 ◽  
Author(s):  
H.-B. Jun ◽  
S.-M. Park ◽  
J.-K. Park ◽  
S.-H. Lee
Keyword(s):  
Organic Matter ◽  
Removal Efficiency ◽  
Particulate Organic Matter ◽  
Domestic Sewage ◽  
Organic Load ◽  
Major Constituent ◽  
Anaerobic Sludge ◽  
Recycle Ratio ◽  
Particle Counts ◽  
Removal Efficiencies

Equalization characteristics of the upflow sludge blanket – aerated bio-filter (USB-AF) were investigated with the fluctuated raw domestic sewage. Recycle of nitrified effluent from AF to USB triggered the equalization characteristics of the sludge blanket on both soluble and particulate organic matter. Increment of EPS in sludge blanket by nitrate recycle was detected and removal of turbidity and particulates increased at higher recycle ratios by bio-flocculation. Increased TCOD removal in the USB was due to both denitrification of recycled nitrate and entrapment of the particulate organic matter in sludge blanket. Capture of both soluble and particulate organic matter increased sludge blanket layer in the USB, which improved the reactor performances and reduced the organic load on the subsequent AF. Overall TCOD and SS removal efficiencies were about 98% and 96%, respectively in the USB-AF system. Turbidity in the USB effluent was about 44, 20 and 5.5 NTU, at recycle ratios of 0, 100 and 200%, respectively. Particle counts in the range 2–4 μm in the USB effluent were higher than those in influent without nitrate recycle, while particle counts in the range of 0.5–15 μm in the USB effluent decreased 70% at recycle ratio of 200%. The major constituent of EPS extracted from anaerobic sludge was protein and total EPS increased from 109.1 to 165.7 mg/g-VSS with nitrate recycle of 100%. Removal efficiency and concentration of T-N in the UBS-AF effluent was over 70% and below 16 mg/L, respectively.

Sign in / Sign up

Export Citation Format

Share Document