Rheological properties of anaerobic sludge

ABSTRACT

The flow properties of anaerobic sludges depend heavily on rheological properties which usually use many models to express the quantitative relationship between rheology parameters. These models deduced from continuum mechanics are not sufficient for engineering design because they are limited to rheological behavior of fluids. Many factors affect the rheological properties of anaerobic sludges by forming or changing microstructure between particles, particle-organic, etc. Traditional methods used to test rheological properties of sludge are insufficient and inaccurate to understand the mechanism of the changing rheological properties due to the research staying on the macroscopical phenomena. Here the common models and the main factor of solid concentration, temperature and organic matters are given, together with the influence mechanism of these factors on rheological property. Microrheology methods are discussed because of its effectiveness and accuracy in studying rheological property, which need not to consider the multi-component nature and anisotropism of anaerobic sludges. Finally the rheological properties of, and current research on, anaerobic sludge and the relationship with flow property are described.

KEYWORDS:

• Rheological property
• microrheology approaches
• pipe flow
• continuum mechanics model
• anaerobic sludge

Disclosure statement

No potential conflict of interest was reported by the authors.