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Characteristics and stability of aerobic granules cultivated with different starvation time


The characteristics of aerobic granules at steady state and the effects of starvation time on the stability of aerobic granules during the long-term operation were investigated in three sequencing batch reactors (SBRs R1–R3). The SBRs were operated with a cycle time of 1.5, 4.0, and 8.0 h, respectively, which resulted in a starvation time of 0.8, 3.3, and 7.3 h in three reactors, respectively. Results showed that aerobic granules were successfully cultivated in the three reactors, but the granules in R2 with a starvation time of 3.3 h showed the highest density and the best settleability at steady state. It is obvious that the starvation time has an optimum value in terms of settleability of granules. In addition, it was found that the coexistence of a minority of fluffy granules with smooth granules was the potential unstable factor in R1 with a starvation time of 0.8 h at the steady state. The sudden dominance of fluffy granules in R1 after the 160-day operation led to the operation failure of the reactor R1, whereas the granules in R2 with a starvation time of 3.3 h and R3 with a starvation time of 7.3 h showed good stability during the long-term operation. As short starvation time leads to the instability of granules, and long starvation time is not advisable for practical application due to low efficiency, starvation time should be controlled in a reasonable range.

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  1. APHA (1998) Standard methods for the examination of water and wastewater, 20th edn. American Public Health Association, Washington, DC

  2. Beun JJ, Hendriks A, van Loosdrecht MCM, Morgenroth E, Wilderer PA, Heijnen JJ (1999) Aerobic granulation in a sequencing batch reactor. Water Res 33:2283–2290

  3. de Kreuk MK, van Loosdrecht MCM (2004) Selection of slow growing organisms as a means for improving aerobic granular sludge stability. Water Sci Technol 49:9–17

  4. Dubois M, Gilles KA, Hamilton JK, Rebers PA, Smith F (1956) Colorimetric method for determination of sugars and related substances. Anal Chem 28:350–356

  5. Li ZH, Kuba T, Kusuda T (2006) The influence of starvation phase on the properties and the development of aerobic granules. Enzyme Microb Technol 38:670–674

  6. Liu Y, Tay JH (2004) State of the art of biogranulation technology for wastewater treatment. Biotechnol Adv 22:533–563

  7. Liu Y, Yang SF, Tay JH (2004a) Improved stability of aerobic granules by selecting slow-growing nitrifying bacteria. J Biotechnol 108:161–169

  8. Liu YQ, Liu Y, Tay JH (2004b) The effects of extracellular polymeric substances on the formation and stability of biogranules. Appl Microbiol Biotechnol 65:143–148

  9. Liu YQ, Liu Y, Tay JH, Ivanov V, Moy BYP, Liu Y, Tay STL (2005) Influence of phenol on nitrification by aerobic granules. Process Biochem 40:3285–3289

  10. Liu YQ, Tay JH, Moy BYP (2006) Characteristics of aerobic granular sludge in a sequencing batch reactor with variable aeration. Appl Microbiol Biotechnol 71:761–766

  11. Morgenroth E, Sherden T, van Loosdrecht MCM, Heijnen JJ, Wilderer PA (1997) Aerobic granular sludge in a sequencing batch reactor. Water Res 31:3191–3194

  12. Moy BYP, Tay JH, Toh SK, Liu Y, Tay STL (2002) High organic loading influences the physical characteristics of aerobic sludge granules. Lett Appl Microbiol 34:407–412

  13. Pernelle JJ, Gaval G, Cotteux E, Duchene P (2001) Influence of transient substrate overloads on the proliferation of filamentous bacterial populations in an activated sludge pilot plant. Water Res 35:129–134

  14. Qin L, Tay JH, Liu Y (2004) Selection pressure is a driving force of aerobic granulation in sequencing batch reactors. Process Biochem 39:579–584

  15. Shin HS, Lim KH, Park HS (1992) Effect of shear stress on granulation in oxygen aerobic upflow sludge bed reactors. Water Sci Technol 26:601–605

  16. Stoscheck CM (1990) Quantitation of protein. Methods Enzymol 182:50–69

  17. Tay JH, Liu QS, Liu Y (2001a) The effects of shear force on the formation, structure and metabolism of aerobic granules. Appl Microbiol Biotechnol 57:227–233

  18. Tay JH, Liu QS, Liu Y (2001b) Microscopic observation of aerobic granulation in sequential aerobic sludge blanket reactor. J Appl Microbiol 91:168–175

  19. Tay JH, Pan S, He YX, Tay STL (2004) Effect of organic loading rate on aerobic granulation. I. Reactor performance. J Environ Eng-ASCE 130:1094–1101

  20. Tijhuis L, van Loosdrecht MCM, Heijnen JJ (1994) Formation and growth of heterotrophic aerobic biofilms on small suspended particles in airlift reactors. Biotechnol Bioeng 44:595–608

  21. van Loosdrecht MCM, Pot MA, Heijnen JJ (1997) The role of storage polymers in bioprocesses. Water Sci Technol 35:41–47

  22. Zheng YM, Yu HQ, Liu SJ, Liu XZ (2006) Formation and instability of aerobic granules under high organic loading conditions. Chemosphere 63:1791–1800

  23. Zhu JR, Liu CX (1999) Cultivation and physico-chemical characteristics of granular activated sludge in alternation of anaerobic/aerobic process. Chin J Environ Sci 20:38–41

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This work was supported by research funds from Nanyang Technological University to Professor Joo-Hwa Tay. Dr. Yong-Qiang Liu is supported by a Singapore Millennium Foundation (SMF) postdoctoral scholarship.

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Correspondence to Yong-Qiang Liu.

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Liu, Y., Tay, J. Characteristics and stability of aerobic granules cultivated with different starvation time. Appl Microbiol Biotechnol 75, 205–210 (2007).

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  • Aerobic granules
  • Starvation
  • Characteristics
  • Stability
  • SBR