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Updated: Jul 3, 2026
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Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Granular sludge formation in upflow anaerobic sludge blanket (UASB) reactors
1The Anaerobic Microbiology/Biotechnology Research Group, Institute of Environmental Science and Engineering, Building 115, The Technical University of Denmark, DK-2800 Lyngby, Denmark.
Biotechnology and Bioengineering
|February 5, 1996
Summary
The development of granular sludge is crucial for upflow anaerobic sludge blanket (UASB) reactors. Extracellular polymers play a key role in granule structure, supporting diverse microbial communities for efficient wastewater treatment.
Area of Science:
- Environmental Microbiology
- Biotechnology
- Wastewater Treatment Engineering
Background:
- Upflow anaerobic sludge blanket (UASB) reactors rely on granular sludge for effective operation.
- Understanding the microbiology and formation mechanisms of this granular sludge is essential.
Purpose of the Study:
- To discuss the state of the art in UASB reactor technology.
- To focus on the microbiology of immobilized anaerobic bacteria and granule formation.
- To provide criteria for assessing granular sludge development.
Main Methods:
- Analysis of granular sludge characteristics (density, diameter, composition).
- Identification of microbial communities using immunological methods.
- Observation of bacterial microcolonies and interspecies electron transfer.
Main Results:
- Granular sludge development is key for UASB reactors, with criteria based on density and diameter.
- Granule composition varies (10-90% inorganic matter), with extracellular polymers (proteins, polysaccharides) vital for structure.
- Key methanogens include Methanosaeta spp. and Methanosarcina spp., alongside hydrogen/formate utilizers like Methanobacterium spp.
- Bacterial microcolonies and interspecies hydrogen transfer are observed, with internal organization dependent on wastewater composition.
Conclusions:
- Extracellular polymers are more critical for granule structure than inorganic content.
- Diverse microbial consortia, including syntrophic bacteria, contribute to wastewater degradation within granules.
- A four-step model for initial granular sludge development is proposed.
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