EFFECTS OF SHORT SOLIDS RETENTION TIME ON PERFORMANCE AND MEMBRANE FOULING OF SUBMERGED ANOXIC/OXIC MEMBRANE BIOREACTORS

2005 ◽  
Vol 2005 (14) ◽  
pp. 2119-2127
Author(s):  
T.W. Tan ◽  
H.Y. Ng ◽  
S.L Ong ◽  
C.A. Toh ◽  
Z.P. Loo
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Solids Retention Time ◽  
Solids Retention

scholarly journals Operation of Submerged Anaerobic Membrane Bioreactors at 20 °C: Effect of Solids Retention Time on Flux, Mixed Liquor Characteristics and Performance

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1525
Author(s):  
Santiago Pacheco-Ruiz ◽  
Sonia Heaven ◽  
Charles J. Banks
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Oxygen Demand ◽  
Membrane Bioreactors ◽  
Transmembrane Pressure ◽  
Capillary Suction ◽  
Solids Retention Time ◽  
Anaerobic Membrane Bioreactors ◽  
Solids Retention

Four flat-sheet submerged anaerobic membrane bioreactors ran for 242 days on a simulated domestic wastewater with low Chemical Oxygen Demand (COD) and high suspended solids. Organic loading was maintained around 1.0 g COD L−1 day−1, while solids retention time (SRT) was varied from 20–90 days. This was achieved at a constant membrane flux, maintained by adjusting transmembrane pressure (TMP) in the range 1.8-9.8 kPa. Membrane fouling was assessed based on the required TMP, with mixed liquors characterised using capillary suction time, frozen image centrifugation and quantification of extracellular polymeric substances (EPS). SRT had a significant effect on these parameters: fouling was least at an SRT of 30 days and highest at 60 days, with some reduction as this extended to 90 days. Operation at SRT <30 days showed no further benefits. Although operation at a short SRT was optimal for membrane performance it led to lower specific methane productivity, higher biomass yields and higher effluent COD. Short SRT may also have accelerated the loss of essential trace elements, leading to reduced performance under these conditions. A COD-based mass balance was conducted, including both biomass and methane dissolved in the effluent.

scholarly journals The influence of solids retention time on activated sludge bioflocculation and membrane fouling in a membrane bioreactor (MBR)

2012 ◽  
Vol 401-402 ◽  
pp. 48-55 ◽  
Author(s):  
R. Van den Broeck ◽  
J. Van Dierdonck ◽  
P. Nijskens ◽  
C. Dotremont ◽  
P. Krzeminski ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Solids Retention Time ◽  
Solids Retention

Effects of solid retention time on the performance of submerged anoxic/oxic membrane bioreactor

2006 ◽  
Vol 53 (6) ◽  
pp. 7-13 ◽  
Author(s):  
H.Y. Ng ◽  
T.W. Tan ◽  
S.L. Ong ◽  
C.A. Toh ◽  
Z.P. Loo
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Domestic Wastewater ◽  
Membrane Bioreactors ◽  
Complete Conversion ◽  
Solid Retention Time ◽  
Solids Retention ◽  
Nitrogen Concentrations ◽  
Removal Efficiencies

In this study, four similar bench-scale submerged Anoxic/Oxic Membrane Bioreactors (MBR) were used simultaneously to investigate the effects of solids retention time (SRT) on organic and nitrogen removal in MBR for treating domestic wastewater. COD removal efficiencies in all reactors were consistently above 94% under steady state conditions. Complete conversion of NH4+-N to NO3--N was readily achieved over a feed NH4+-N concentration range of 30 to 50 mg/L. It was also observed that SRT did not significantly affect the nitrification in the MBR systems investigated. The average denitrification efficiencies for the 3, 5, 10 and 20 days SRT operations were 43.9, 32.6, 47.5 and 66.5%, respectively. In general, the average effluent nitrogen concentrations, which were mainly nitrate, were about 22.2, 27.6, 21.7 and 13.9 mg/L for the 3, 5, 10 and 20 days SRT systems, respectively. The rate of membrane fouling at 3 days SRT operation was more rapid than that observed at 5 days SRT. No fouling was noted in the 10 days and 20 days SRT systems during the entire period of study.

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