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| Analysis of the filterability of mixed sludge under low nutrition in MBR. |
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Abstract During a 16d period, membrane bioreactor (MBR) was operated without nutrient addition to the mixed liquid. Soluble microbial products (SMP), particle size distributions (PSD) of flocs, extracellular polymeric substances (EPS) and molecular weight (MW) distributions of SMP were periodically monitored. The modified fouling index (MFI) was used to investigate the filterability of mixed sludge closely related with the SMP and EPS. The results showed that the MFI increased rapidly from 1.8×104 to 7.3×104s/L2, which indicated the long time endogenous metabolism process had a negative influence on the filterability of mixed sludge in MBR. It was also found that the increase of SMP with MW >10kDa in supernatant and small particles in the range of 1~10μm in sludge remarkably affected the filterability of mixed sludge under long time low nutrition.
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Received: 22 September 2008
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