The effect of aeration and non-aeration time on simultaneous organic, nitrogen and phosphorus removal using an intermittent aeration membrane bioreactor

2002 ◽  
Vol 46 (9) ◽  
pp. 193-200 ◽  
Author(s):  
Z. Ujang ◽  
M.R. Salim ◽  
S.L. Khor

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 mm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.

2000 ◽  
Vol 41 (10-11) ◽  
pp. 217-225 ◽  
Author(s):  
G.T. Seo ◽  
T.S. Lee ◽  
B.H. Moon ◽  
J.H. Lim ◽  
K.S. Lee

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.


2021 ◽  
Author(s):  
Liya Li ◽  
Jingwei Feng ◽  
Liu Zhang ◽  
Hao Yin ◽  
Chunli Fan ◽  
...  

Abstract Four subsurface flow constructed wetlands (SFCWs) filled with different substrates including ceramsite, ceramsite + pyrite, ceramsite + ferrous sulfide, and ceramsite + pyrite + ferrous sulfide (labeled as SFCW-S1, SFCW-S2, SFCW-S3, and SFCW-S4) were constructed, and the removal of nitrogen and phosphorus by these SFCWs coupled with intermittent aeration in the front section was discussed. The key findings from different substrate analyses, including nitrification and denitrification rate, enzyme activity, microbial community structure, and the X-ray diffraction, revealed the nitrogen and phosphorus removal mechanism. The results showed that the nitrogen and phosphorus removal efficiency for SFCW-S1 always remains the lowest, and the phosphorus removal efficiency for SFCW-S4 is recorded as the highest one. However, after controlling the dissolved oxygen by intermittent aeration in the front section of SFCWs, the nitrogen and phosphorus removal efficiencies of SFCWs-S2 and S4 becomes higher than those of SFCW-S1, and SFCW-S3. It was noticed that the pollutants were removed mainly in the front section of the SFCWs. Both precipitation and adsorption on the substrate were the main mechanisms for phosphorus removal. A minute difference of nitrification rate and ammonia monooxygenase activity was observed in the SFCWs aeration zone. The denitrification rates, nitrate reductase, nitrite reductase, and electron transport system activity for SFCW-S2 and SFCW-S4 were higher than those detected for SFCW-S1 and SFCW-S3 in the non-aerated zone. Proteobacteria was the largest phyla found in the SFCWs. Moreover, Thiobacillus occupied a large proportion found in SFCW-S2, and SFCW-S4, and it played a crucial role in pyrite-driven autotrophic denitrification.


2011 ◽  
Vol 396-398 ◽  
pp. 1995-2001
Author(s):  
Lian Yu

Based on a modified Carrousel oxidation ditch process acclimated with synthetic wastewater,effect of SRT on nitrogen and phosphorus removal occurred in the system was investigated. The results indicated that SRT was prominent to nitrogen and phosphorus removal. The removal efficiency of nitrogen was better with SRT extension and that the removal efficiency of phosphorus was better with SRT shortness. With the operation conditions of water temperature 30°C, SRT 11days, the removal efficiency of TN and TP reached 85.4% and 74.9%, which indicated that nitrogen and phosphorus removals were best.


2017 ◽  
Vol 76 (5) ◽  
pp. 1044-1058 ◽  
Author(s):  
Amir Mohammad Mansouri ◽  
Ali Akbar Zinatizadeh

The performance of two bench scale activated sludge reactors with two feeding regimes, continuous fed (an up-flow aerobic/anoxic sludge fixed film (UAASFF) bioreactor) and batch fed (sequencing batch reactor (SBR)) with intermittent aeration, were evaluated for simultaneous nutrients (N, P) removal. Three significant variables (retention/reaction time, chemical oxygen demand (COD): N (nitrogen): P (phosphorus) ratio and aeration time) were selected for modeling, analyzing, and optimizing the process. At high retention time (≥6 h), two bioreactors showed comparable removal efficiencies, but at lower hydraulic retention time, the UAASFF bioreactor showed a better performance with higher nutrient removal efficiency than the SBR. The experimental results indicated that the total Kjeldahl nitrogen removal efficiency in the UAASFF increased from 70.84% to 79.2% when compared to SBR. It was also found that the COD removal efficiencies of both processes were over 87%, and total nitrogen and total phosphorus removal efficiencies were 79.2% and 72.98% in UAASFF, and 71.2% and 68.9% in SBR, respectively.


2016 ◽  
Vol 38 (7) ◽  
pp. 806-815 ◽  
Author(s):  
Tiago José Belli ◽  
Jossy Karla Brasil Bernardelli ◽  
Rayra Emanuelly da Costa ◽  
João Paulo Bassin ◽  
Miriam Cristina Santos Amaral ◽  
...  

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 353
Author(s):  
Yi Ding ◽  
Zhansheng Guo ◽  
Junxue Mei ◽  
Zhenlin Liang ◽  
Zhipeng Li ◽  
...  

A microalgae membrane bioreactor (MMBR) with internal circulating fluidized bed (ICFB) was constructed at room temperature to study the removal efficiency of marine aquaculture wastewater pollutants and continuously monitor the biomass of microalgae. Within 40 days of operation, the removal efficiency of NO3−–N and NH4+–N in the ICFB-MMBR reached 52% and 85%, respectively, and the removal amount of total nitrogen (TN) reached 16.2 mg/(L·d). In addition, the reactor demonstrated a strong phosphorus removal capacity. The removal efficiency of PO43−–P reached 80%. With the strengthening of internal circulation, the microalgae could be distributed evenly and enriched quickly. The maximum growth rate and biomass concentration reached 60 mg/(L·d) and 1.4 g/L, respectively. The harvesting of microalgae did not significantly affect the nitrogen and phosphorus removal efficiency of ICFB-MMBR. The membrane fouling of the reactor was investigated by monitoring transmembrane pressure difference (TMP). Overall, the membrane fouling cycle of ICFB-MMBR system was more than 40 days.


2018 ◽  
Vol 77 (6) ◽  
pp. 1505-1513 ◽  
Author(s):  
Yassine Ouarda ◽  
Mehdi Zolfaghari ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Gerardo Buelna ◽  
...  

Abstract In this study, a submerged membrane bioreactor was used to study the effect of low and high bisphenol A (BPA) concentration on the sludge biological activity. The pilot was operated over 540 days with hydraulic retention time and solid retention time of 5.5 hours and 140 days, respectively. As a hydrophobic compound, BPA was highly adsorbed by activated sludge. In lower concentrations, the biodegradation rate remained low, since the BPA concentration in the sludge was lower than 0.5 mg/g TS; yet, at an influent concentration up to 15 mg/L, the biodegradation rate was increasing, resulting in 99% BPA removal efficiency. The result for chemical oxygen demand removal showed that BPA concentration has no effect on the heterotrophic bacteria that were responsible for the organic carbon degradation. In higher concentrations, up to 16 mg of BPA was used for each gram of sludge as a source of carbon. However, the activity of autotrophic bacteria, including nitrifiers, was completely halted in the presence of 20 mg/L of BPA or more. Although nitrification was stopped after day 400, ammonia removal remained higher than 70% due to air stripping. Assimilation by bacteria was the only removal pathway for phosphorus, which resulted in an average 35% of P-PO4 removal efficiency.


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