Sludge Water Characteristics Under Different Separation Methods from a Membrane Bioreactor

Chunhai Wei, Gary L. Amy

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


The concept of sludge water was proposed to integrate the relative terminologies and its characteristics under different separation methods from a membrane bioreactor (MBR) were investigated in this study. Based on chemical oxygen demand (COD) and three-dimensional fluorescence excitation-emission matrix (F-EEM), and compared with the control (gravitational sedimentation), some suspended particulate organics or biopolymer clusters (mainly proteins) were released from sludge flocs into the supernatant after centrifugation under low to middle centrifugal forces (10-4000 g) and then aggregated into a pellet under high centrifugal forces (10000-20000 g). Filtration (1.2 μm glass fiber filter) produced sludge water with a lower biopolymers concentration than the control (gravitational sedimentation followed by filtration) due to cake layer formation during filtration. As for centrifugation followed by filtration, low to middle centrifugal forces did not significantly affect sludge water characteristics but high centrifugal forces reduced the concentrations of some proteins in sludge water from advanced analytical protocols including F-EEM and liquid chromatography with on-line organic carbon detection (LC-OCD), demonstrating a low to middle centrifugal force suitable for MBR sludge water separation. From LC-OCD, the main fractions of sludge water were humic substances and building blocks, low molecular weight neutrals and biopolymers (mainly proteins rather than polysaccharides). Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science and Technology to view the supplemental file. © 2013 Copyright Taylor and Francis Group, LLC.
Original languageEnglish (US)
Pages (from-to)2540-2548
Number of pages9
JournalSeparation Science and Technology
Issue number17
StatePublished - Nov 22 2013

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work has been financed by the KAUST-UIUC Academic Excellence Alliance (AEA) Project entitled with Anaerobic Membrane Bioreactor (AnMBR) with Nano-filtration (NF) Membrane.

ASJC Scopus subject areas

  • Filtration and Separation
  • General Chemical Engineering
  • General Chemistry
  • Process Chemistry and Technology


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