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Updated: May 22, 2026
06:10
Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge
Published on: September 26, 2016
Temperature and salt effects on settling velocity in granular sludge technology
M-K H Winkler1, J P Bassin, R Kleerebezem
1Department of Biotechnology, Delft University of Technology, Julianalaan 67 2628 BC Delft, The Netherlands.
Water Research
|May 23, 2012
Summary
Lowering water temperature and increasing salt concentration significantly reduce granular sludge settling velocity. Granules may initially float in high salt solutions, with recovery time dependent on granule size and salt diffusion dynamics.
Area of Science:
- Environmental Engineering
- Biotechnology
- Water Treatment
Background:
- Granular sludge technology relies on particle settling velocity.
- Understanding factors influencing settling is key for reactor efficiency.
Purpose of the Study:
- To investigate the impact of temperature and salt concentration on granular sludge settling velocity.
- To analyze the dynamics of salt diffusion and its effect on granule mass and settling.
Main Methods:
- Experimental evaluation of settling velocities under varying temperatures (5°C to 40°C).
- Assessment of settling behavior in solutions with different salt concentrations.
- Observation of granule buoyancy and mass changes due to salt diffusion.
Main Results:
- Settling velocity decreased twofold as temperature dropped from 40°C to 5°C.
- Increased salt concentrations led to reduced settling velocities.
- Granules exhibited initial flotation in high salt solutions, with recovery time linked to diameter and salt diffusion rates.
Conclusions:
- Temperature and salt concentration are critical parameters for designing and operating granular sludge reactors.
- Monitoring these factors enhances sludge management in anaerobic and aerobic systems.
- Findings explain difficulties in starting granular sludge reactors at low temperatures.
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