Formation and characteristics of nitritation granules cultivated in sequencing batch reactor by stepwise increase of N/C ratio

2011 ◽  
Vol 64 (7) ◽  
pp. 1479-1487 ◽  
Author(s):  
Ling-yun Li ◽  
Yong-zhen Peng ◽  
Shu-ying Wang ◽  
Lei Wu ◽  
Yong Ma ◽  
...  
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Removal ◽  
Nitrogen Loading ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Nitrifying Bacteria ◽  
Stepwise Increase ◽  
Start Up ◽  
Total Bacteria

The cultivation of nitritation granules in sequencing batch reactor (SBR) by seeding conventional floccular activated sludge was investigated using ethanol-based synthetic wastewater. Reducing settling time offers selection pressure for aerobic granulation, and stepwise increase of influent N/C ratio can help to selectively enrich ammonia oxidizing bacteria (AOB) in aerobic granules. The spherical shaped granules were observed with the mean diameter of 1.25 mm, average settling velocity of 1.9 cm s−1 and the sludge volume index (SVI) of 18.5–31.4 ml g−1. After 25 days of operation, the nitrogen loading rate reached 0.0455 kg NH4+-N (kg MLSS·d)−1, which was 4.55 times higher than that of the start-up period. The mature granules showed high nitrification ability. Ammonia removal efficiency was above 95% and nitrite accumulation ratio was in the range of 80–95%. The nitrifying bacteria were quantified by fluorescence in situ hybridization analysis, which indicated that AOB was 14.9 ± 0.5% of the total bacteria and nitrite oxidizing bacteria (NOB) was 0.89 ± 0.1% of the total bacteria. Therefore, AOB was the dominant nitrifying bacteria. It was concluded that the associated inhibition of free ammonia at the start of each cycle and free nitrous acid during the later phase of aeration may be the key factors to start up and maintain the stable nitritation.

scholarly journals Performance of the anammox sequencing batch reactor treating synthetic and real landfill leachate

2018 ◽  
Vol 44 ◽  
pp. 00179 ◽  
Author(s):  
Mariusz Tomaszewski ◽  
Grzegorz Cema ◽  
Tomasz Twardowski ◽  
Aleksandra Ziembińska-Buczyńska
Keyword(s):  
Nitrogen Removal ◽  
Landfill Leachate ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Nitrogen Loading ◽  
Synthetic Wastewater ◽  
High Nitrogen ◽  
Removal Capacity ◽  
Anammox Activity ◽  
Anammox Process

The anaerobic ammonium oxidation (anammox) process is one of the most energy efficient and environmentally-friendly bioprocess for the treatment of the wastewater with high nitrogen concentration. The aim of this work was to study the influence of the high nitrogen loading rate (NLR) on the nitrogen removal in the laboratory-scale anammox sequencing batch reactor (SBR), during the shift from the synthetic wastewater to landfill leachate. In both cases with the increase of NLR from 0.5 to 1.1 – 1.2 kg N/m3d, the nitrogen removal rate (NRR) increases to about 1 kg N/m3d, but higher NLR caused substrates accumulation and affects anammox process efficiency. Maximum specific anammox activity was determined as 0.638 g N/g VSSd (NRR 1.023 kg N/m3d) and 0.594 g N/g VSSd (NRR 1.241 kg N/m3d) during synthetic and real wastewater treatment, respectively. Both values are similar and this is probably the nitrogen removal capacity of the used anammox biomass. This indicates, that landfill leachate did not influence the nitrogen removal capacity of the anammox process.

Improving Wastewater Nitrogen Removal and Reducing Effluent NOx - -N by an Oxygen-Limited Process Consisting of a Sequencing Batch Reactor and a Sequencing Batch Biofilm Reactor

2019 ◽  
Vol 17 (7) ◽  
Author(s):  
Mehdi Hajsardar ◽  
Seyed Mehdi Borghei ◽  
Amir Hessam Hassani ◽  
Afshin Takdastan
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Nitrogen Loading ◽  
Biofilm Reactor ◽  
Synthetic Wastewater ◽  
The Novel ◽  
Sequencing Batch Biofilm Reactor ◽  
Do Concentration

Abstract A series of reactors including a sequencing batch reactor (SBR) and a sequencing batch biofilm reactor (SBBR) were used for nitrogen removal. The aim of this study was simultaneous removal of NH4+-N and NOx–-N from synthetic wastewater. In the novel proposed method, the effluent from SBR was sequentially introduced into SBBR, which contained 0.030 m3 biofilm carriers, so the system operated under a paired sequence of aerobic-anoxic conditions. The effects of different carbon sources and aeration conditions were investigated. A low dissolved oxygen (DO) level in the biofilm depth of the fixed-bed process (SBBR) simulated the anoxic phase conditions. Accordingly, a portion of NH4+-N that was not converted to NO3–-N by the SBR process was converted to NO3–-N in the outer layer of the biofilm in the SBBR process. Further, simultaneous nitrification and denitrification (SND) was achieved in the SBBR where NO2–-N was converted to N2 directly, before NO3–-N conversion (partial nitrification). The level of mixed liquid suspended solids (MLSS) was 2740 mg/l at the start of the experiments. The required carbon source (C: N ratio of 4) was provided by adding an internal carbon source (through step feeding) or ethanol. Firstly, as part of the system (SBR and SBBR), SBR operated at a DO level of 1 mg/l while SBBR operated at a DO concentration of 0.3 mg/l during Run-1. During Run-2, the system operated at the low DO concentration of 0.3 mg/l. When the source of carbon was ethanol, the nitrogen removal rate (RN) was higher than the operation with an internal carbon source. When the reactors were operated at the same DO concentration of 0.3 mg/l, 99.1 % of the ammonium was removed. The NO3–-N produced during the aerobic SBR operation of the novel method was removed in SBBR reactor by 8.3 %. The concentrations of NO3--N and NO2–-N in the SBBR effluent were reduced to 2.5 and 5.5 mg/l, respectively. Also, the total nitrogen (TN) removal efficiency was 97.5 % by adding ethanol at the DO level of 0.3 mg/l. When C:N adjustment was carried out SND efficiency at C:N ratio of 6.5 reached to 99 %. The increasing nitrogen loading rate (NLR) to 0.554 kg N/m3 d decreased SND efficiency to 80.7 %.

Cultivation of polyhydroxybutyrate-rich aerobic granular sludge in a sequencing batch reactor

2006 ◽  
Vol 6 (6) ◽  
pp. 81-87 ◽  
Author(s):  
J. Wang ◽  
H.Q. Yu
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Second Step ◽  
Sludge Volume Index ◽  
Flat Shape ◽  
Sludge Granulation

In this study a two-step strategy was adopted to cultivate Polyhydroxybutyrate (PHB)-rich aerobic granular sludge in a sequencing batch reactor (SBR) fed with a synthetic wastewater. In the first step both oxygen and ammonia were initially limited, in order to enhance the PHB-storage ability of sludge. In the second step granular sludge was cultivated to get a high PHB volumetric productivity. The PHB content of sludge increased to 43.1±2.0% in the first step. During the sludge granulation, the PHB content was constant at 40±4.6%. With the granulation, the settling ability of the PHB-rich sludge continuously improved, as evidenced by a decreased sludge volume index. The matured PHB-rich granular sludge presented a buff color and regular morphology with elliptical and flat shape.

Aerobic granular sludge: a promising technology for decentralised wastewater treatment

2006 ◽  
Vol 53 (9) ◽  
pp. 79-85 ◽  
Author(s):  
Z.H. Li ◽  
T. Kuba ◽  
T. Kusuda
Keyword(s):  
Sequencing Batch Reactor ◽  
Loading Rate ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Fast Settling

In order to evaluate the characteristics of aerobic granular sludge, a sequencing batch reactor, feeding with synthetic wastewater at the organic loading rate of 8 kg COD/m3 d, was employed on the laboratory scale. Granules occurred in the reactor within 1 week after the inoculation from conventional flocculent sludge. Aerobic granular sludge was characterised by the outstanding settling properties and considerable contaminates removal efficiencies. The SVI30 values were in the range of 20 to 40 ml g−1. However, the sludge volume index of short settling time (e.g. SVI10 – 10 min) is suggested to describe the fast settling properties of aerobic granular sludge. The potential application in the decentralised system is evaluated from the point view of footprint and high bioactivity. The occurrence of sloughing, resulting from the outgrowth of filamentous organisms, would be responsible for the instability of aerobic granules. The starvation phase should therefore be carefully controlled for the maintenance and stability of aerobic granular sludge system.

scholarly journals Nitrogen Removal for Liquid-Ammonia Mercerization Wastewater via Partial Nitritation/Anammox Based on Zeolite Sequencing Batch Reactor

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2234
Author(s):  
Lei Zheng ◽  
Yongxing Chen ◽  
Songwei Zhou ◽  
Yuchen Chen ◽  
Xingxing Wang ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Textile Industry ◽  
Liquid Ammonia ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Removal ◽  
Nitrogen Loading ◽  
Nitrite Accumulation ◽  
Sequencing Analysis ◽  
Partial Nitritation

Liquid-ammonia mercerization is commonly used to enhance the quality of cotton fabric in the textile industry, resulting in a large amount of liquid-ammonia mercerization wastewater (LMWW) containing high concentration of ammonia to be disposed of. This study proposes a partial nitritation/anammox (PN/A) process based on stable nitritation by a zeolite sequencing batch reactor (ZSBR) for the nitrogen removal of LMWW. The ZSBR could quickly achieve stably full nitritation with a nitrite accumulation ratio higher than 97% and an ammonia removal rate of 0.86 kg N·m−3·d−1 for the raw LMWW with an ammonia level of 1490 mg/L. In order to avoid anammox inhibition by free nitrous acid, the ZSBR was successfully changed to PN operation with diluted LMWW for effluent meeting anammox requirements. The next anammox reactor (an up-flow blanket filter (UBF)) realized a total nitrogen removal efficiency of 70.0% with a NLR (nitrogen loading rate) of 0.82 kg N·m−3·d−1 for LMWW. High-throughput sequencing analysis results indicated that Nitrosomonas and Candidatus Kuenenia were the dominant bacteria in ZSBR and UBF, respectively. All results revealed that the PN/A process based on ZSBR as the PN pretreatment process was feasible for LMWW, facilitating cost-effective and low-carbon nitrogen removal for LMWW treatment in the textile industry in the future.

Fast start-up of a pilot-scale deammonification sequencing batch reactor from an activated sludge inoculum

2010 ◽  
Vol 61 (6) ◽  
pp. 1393-1400 ◽  
Author(s):  
Y. Jeanningros ◽  
S. E. Vlaeminck ◽  
A. Kaldate ◽  
W. Verstraete ◽  
L. Graveleau
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Pilot Scale ◽  
Nitrogen Loading ◽  
Ammonium Concentration ◽  
Nitrite Accumulation ◽  
Combined Application ◽  
Start Up ◽  
Cost Efficient ◽  
High Nitrogen Loading

Deammonification involves the combined application of aerobic and anoxic ammonium-oxidizing bacteria (AerAOB & AnAOB) and allows to treat wastewaters with a high ammonium concentration in a sustainable and cost-efficient way. So far, it could take more than one year to start up the process, even with the addition of AnAOB enriched inocula. In contrast, we started up a deammonifying reactor for the treatment of sludge digestate in less than four months without any AnAOB enriched inoculum. In a single sequencing batch reactor (SBR) of 3 m3, nitritation and anammox were performed without nitrite accumulation. Larger biomass aggregates (>1.0 mm) had a typical reddish colour, but FISH also showed that small aggregates (<0.25 mm) contained a considerable amount of AnAOB. The AerAOB were related to Nitrosomonas halophila, N. eutropha and N. halophila, and the AnAOB to “Candidatus Kuenenia & Brocadia”, as shown by FISH. Our results show that the deammonification inoculum does not play an important role, and that the AnAOB can quickly develop under the proper aerational conditions. Nitrogen was removed stably at high nitrogen loading rates (740 mg N/L/d) and removal efficiency (90%).

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.

scholarly journals Feasibility of a pulsed sequencing batch reactor with anaerobic aggregated biomass for the treatment of low strength wastewaters

1997 ◽  
Vol 35 (1) ◽  
pp. 193-198 ◽  
Author(s):  
A. G. Brito ◽  
A. C. Rodrigues ◽  
L. F. Melo
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Anaerobic Bacteria ◽  
Synthetic Wastewater ◽  
Solid Contact ◽  
Transfer Resistance ◽  
Preliminary Study ◽  
Flow Turbulence ◽  
Low Strength ◽  
Swept Volume

This study concerns an assessment of a SBR operation that associates anaerobic aggregated biomass with a pulsed action during the reaction phase, a system named Pulsed Sequencing Batch Reactor (P-SBR). The system uses a diaphragm pump as a pulsator unit to increase the liquid-solid contact, in order to avoid dead zones and possible external mass transfer resistance. A preliminary study of the operation of the reactor was performed with a low strength synthetic wastewater with a COD near 1000 mg.1−1 and a sub-optimal temperature of 22°C. A removal efficiency of 60-70% was attained after 5 and 6 hours of reaction time. The respective organic loads were 5 – 6 kg COD.m−3. day−1, thus supporting the feasibility of the P-SBR system for wastewater treatment in such conditions. The results also indicate that a ratio of 1.8%o between the swept volume delivered by the pump and the reactor volume was adequate to promote a flow turbulence in the sludge blanket and that a redox potential of near −400 mV was readily created by anaerobic bacteria after the reactor filling step.

Start-up of an aerobic granular sequencing batch reactor for the treatment of winery wastewater

2009 ◽  
Vol 60 (4) ◽  
pp. 1049-1054 ◽  
Author(s):  
S. López–Palau ◽  
J. Dosta ◽  
J. Mata-Álvarez
Keyword(s):  
Organic Matter ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Particle Diameter ◽  
Granular Sludge ◽  
Average Density ◽  
Aerobic Granular Sludge ◽  
Organic Load ◽  
Winery Wastewater ◽  
Start Up

Aerobic granular sludge was cultivated in a sequencing batch reactor (SBR) in order to remove the organic matter present in winery wastewater. The formation of granules was performed using a synthetic substrate. The selection parameter was the settling time, as well as the alternation of feast-famine periods, the air velocity and the height/diameter ratio of the reactor. After 10 days of operation under these conditions, the first aggregates could be observed. Filamentous bacteria were still present in the reactor but they disappeared progressively. During the start-up, COD loading was increased from 2.7 to 22.5 kg COD/(m3 day) in order to obtain a feast period between 30 and 60 minutes. At this point, granules were quite round, with a particle diameter between 3.0 and 4.0 mm and an average density of 6 g L−1. After 120 days of operation, synthetic media was replaced by real winery wastewater, with a COD loading of 6 kg COD/(m3 day). The decrease of the organic load implied a reduction of the aggregate diameter and a density increase up to 13.2 g L−1. The effluent was free of organic matter and the solids concentration in the reactor reached 6 g VSS L−1.

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