Strength characterization of full-scale aerobic granular sludge

Danny R. de Graaff*, Edward J.H. van Dijk, Mark C.M. van Loosdrecht, Mario Pronk

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

18 Citations (Scopus)
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For a stable operation, the aerobic granular sludge process requires mechanically strong granules in balance with the shear forces in the reactor. Despite a wide general interest in granular stability, the mechanical strength of both anaerobic and aerobic granular sludge received very little attention. In this study, a high-shear method for strength characterization has been evaluated for full-scale aerobic granular sludge (AGS). Abrasion times up to 90 min showed a stable abrasion rate coefficient (K), while prolonged periods of abrasion up to 24 h resulted in a decrease in abrasion rate. Larger granules have higher abrasion rate than smaller granules. No abrasion was observed at low shear rates, indicating a threshold shear rate for abrasion. Lab-scale AGS showed a lower abrasion rate than full-scale AGS. Incubation of full-scale granules in NaCl led to a decrease in abrasion rate at 25 g L−1 NaCl, but incubation in 50 g L−1 NaCl led to a further decrease for only half of the tested granular sludge samples.

Original languageEnglish
Number of pages12
JournalEnvironmental Technology (United Kingdom)
Publication statusPublished - 2018


  • Aerobic granular sludge
  • salinity
  • strength characterization


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  • Aerobic Granular Sludge in Seawater

    de Graaff, D., 2020, 146 p.

    Research output: ThesisDissertation (TU Delft)

    Open Access
    116 Downloads (Pure)

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