Influence of aluminium accumulation on biological nitrification and phosphorus removal in an anoxic–oxic membrane bioreactor

A continuous flow chemical reactor was constructed to study the dephosphorization effect on the effluent of the oxygen-limited internal-loop fluidized membrane bioreactor (IF-MBR) for domestic sewage treatment. Removal effect of total phosphorus (TP) by four coagulants of AlCl3, FeCl3, polyaluminum ferric chloride (PAFC) and polyaluminium chloride (PAC) was evaluated. Results showed that when the ratio of coagulants to TP was 5 (coagulants in terms of Fe and Al), the removal efficiency of TP by FeCl3 was 92.5% and the addition of FeCl3 resulted in an increase in the chromaticity of the effluent. PAC and PAFC had good removal of TP, and the removal percentage achieved 96.2 and 97.4, respectively. However, the flocs they produced were small and light, and the performance in settlement was poor. AlCl3 performed well as a phosphorus removal agent, the removal rate of TP reached 97.4%, and the flocs were large and dense. Based on this, AlCl3 was the best choice for IF-MBR and then the experiment further optimized the Al/P ratio. Results showed that when the Al/P ratio was above 1:1, the effluent TP concentration was lower than 1mg/L; when the ratio was higher than 2.5:1, the effluent TP was lower than 0.5mg/L.

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Two stage intermittent aeration membrane bioreactor for simultaneous organic, nitrogen and phosphorus removal

Water Science & Technology ◽

10.2166/wst.2000.0647 ◽

2000 ◽

Vol 41 (10-11) ◽

pp. 217-225 ◽

Cited By ~ 7

Author(s):

G.T. Seo ◽

T.S. Lee ◽

B.H. Moon ◽

J.H. Lim ◽

K.S. Lee

Keyword(s):

Phosphorus Removal ◽

Membrane Bioreactor ◽

Removal Rate ◽

Domestic Wastewater ◽

Intermittent Aeration ◽

Nitrogen And Phosphorus ◽

Nitrogen And Phosphorus Removal ◽

Aeration Conditions ◽

Two Phases ◽

Filtration Experiment

A submerged membrane bioreactor (SMBR) was operated in 2-stage intermittent aeration for simultaneous removal of organic matter, nitrogen and phosphorus. The system consists of two reactors with a total volume of 0.27 m3 (1st reactor 0.09 m3 and 2nd 0.18 m3). Real domestic wastewater was used as influent to the system. Membrane used for this experiment was hollow fiber polyethylene membrane with pore size of 0.1μm and effective surface area, 4 m2. The membrane was submerged in the 2nd reactor for suction type filtration. Experiment was carried out in two phases varying the time cycles of aeration and non-aeration. SRT was maintained at 25 days and HRT, 16–19 hours. MLSS concentration in the reactors was in the range of 2,700–3,400 mg/l. The MLSS internal recycling ratio was maintained at 100% of influent flow rate. When time cycles of aeration and non-aeration were set at 30/90 min and 60/60 min in reactor 1 and 2, the removal of BOD and COD was 98.3% and 95.6%, respectively. A relatively low nitrogen and phosphorus removal was observed in this condition (73.6% as T–N and 46.6% as T–P). However, with 60/60 min intermittent aeration conditions for both reactors, the removal rate of nitrogen and phosphorus for two weeks steady state were enhanced to 91.6% as TN and 66% as TP, respectively. Further a high organic removal (98% BOD and 96.2% COD) was achieved too. In these conditions, the membrane of flux declined from 0.1 m/d to 0.08 m/d and suction filtration was at 10–12 kPa for a month long operation period.

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Modification of submerged membrane bioreactors (MBRs) by inserting baffles: pilot scale study

Water Science & Technology ◽

10.2166/wst.2007.135 ◽

2007 ◽

Vol 55 (7) ◽

pp. 119-126 ◽

Cited By ~ 6

Author(s):

K. Kimura ◽

M. Enomoto ◽

Y. Watanabe

Keyword(s):

Phosphorus Removal ◽

Membrane Bioreactor ◽

Municipal Wastewater ◽

Pilot Scale ◽

Membrane Bioreactors ◽

Operating Conditions ◽

Feed Water ◽

Simple Modification ◽

Anoxic Conditions ◽

Scale Experiment

Submerged membrane bioreactors (MBRs) have been gaining in popularity in various types of wastewater treatment. One drawback of submerged MBRs is difficulty in removing nitrogen as they are accompanied with intensive aeration inside the reactor and therefore principally operated under aerobic conditions. In order to address this problem, a simple modification for submerged MBRs, insertion of baffles to create alternative aerobic/anoxic conditions, was proposed. In this study, the performance of the proposed baffled membrane bioreactor (BMBR) was investigated based on a pilot-scale experiment using a real municipal wastewater. With appropriate operating conditions, the BMBR could remove more than 70% of total nitrogen contained in the feed water without any external carbon source. The BMBR demonstrated a good treatment performance in terms of TOC and phosphorus removal as well. Increase of trans-membrane pressure difference was subtle, which might be attributed to the alternative creation of aerobic/anoxic conditions.

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Efficient Biological Nutrient Removal in a Membrane Bioreactor Using Denitrifying Phosphorus Removal and Simultaneous Nitrification and Denitrification

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.507.693 ◽

2014 ◽

Vol 507 ◽

pp. 693-701

Author(s):

Jiu Yi Li ◽

Nian Peng Wu ◽

Jin Li ◽

Ai Min Wang ◽

Yong Chen ◽

...

Keyword(s):

Nutrient Removal ◽

Phosphorus Removal ◽

Membrane Bioreactor ◽

Phosphorus Release ◽

Biological Nutrient Removal ◽

Return Flow ◽

Denitrifying Phosphorus Removal ◽

Bioreactor System ◽

Removal Processes ◽

The Impact

Biological nutrient removal (BNR) is generally integrated in municipal wastewater treatment plants to alleviate the impact of treated effluent on receiving watersheds. This paper studies the performance of BNR in a membrane bioreactor system consisting of anaerobic, anoxic, micro-aerobic and aerobic compartments treating a synthetic wastewater containing low organic matters. The membrane bioreactor system designed an anti-stream, stepwise return flow scheme to produce ideal conditions for the occurrence of simultaneous nitrification and denitification and denitrifying phosphorus removal processes. The proposed membrane reactor system has established higher biomass concentrations and ideal environments for biological nutrient removal processes, which results in high nutrient removal efficiencies treating low organic wastewaters. Four compartment configurations in the reactor system minimized the impact of oxidized nitrogen species in return flow on phosphorus release in the anaerobic tank and the anti-stream, stepwise return flow scheme encouraged the utilization of nitrate as the electronic acceptor in phosphorus uptake in the micro-aerobic tank. Denitrifying phosphorus removal and simultaneous nitrification and denitrification processes are the main mechanisms responsible for efficient nutrient removal. High phosphorus release activities and high phosphate concentration in the anaerobic tank make it is potentially feasible to recover phosphorus resource from wastewater.

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Membrane bioreactor configurations for enhanced biological phosphorus removal

Water Science & Technology Water Supply ◽

10.2166/ws.2003.0173 ◽

2003 ◽

Vol 3 (5-6) ◽

pp. 237-244 ◽

Cited By ~ 1

Author(s):

C. Adam ◽

M. Kraume ◽

R. Gnirss ◽

B. Lesjean

Keyword(s):

Phosphorus Removal ◽

Membrane Bioreactor ◽

P Uptake ◽

Raw Water ◽

Enhanced Biological Phosphorus Removal ◽

Biological Phosphorus Removal ◽

N Removal ◽

P Content ◽

Biological Phosphorus ◽

P Removal

A membrane bioreactor (MBR) bench-scale plant (210 L) was operated under two different enhanced biological phosphorus removal (EBPR) configurations, characterised by pre- and postdenitrification mode. Both configurations were operated at 15 d SRT in parallel to a conventional WWTP and fed with degritted raw water. Effluent PT-concentrations were very stable and low between 0.05-0.15 mg/L for both configurations at sludge P-contents of 2-3%P/TS. In contrast to aerobic P-uptake with postdenitrification anoxic P-uptake clearly dominated in the pre-denitrification configuration. N-removal was surprisingly high with up to 96% in the post-denitrification system without resorting to any carbon addition. During P-spiking (influent: -40 mgP/L) the P-content increased up to 6-7.5%P/TS. However, a significant amount of P-removal was due to adsorption and precipitation.

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