Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2009
Volume 12
Issue 1
Topic:
Environmental Development
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Malczewska B. 2009. VARIABILITY OF RHEOLOGICAL PARAMETERS IN FUNCTION OF GRAVIMETRIC CONCENTRATION OF SLUDGE, EJPAU 12(1), #07.
Available Online: http://www.ejpau.media.pl/volume12/issue1/abs-07.html

VARIABILITY OF RHEOLOGICAL PARAMETERS IN FUNCTION OF GRAVIMETRIC CONCENTRATION OF SLUDGE

Beata Malczewska
Institute of Environmental Engineering, Wroc│aw University of Environmental and Life Sciences, Poland

 

ABSTRACT


The paper presents results of rheological
measurements conducted on sewage sludge from settling tanks of several municipal
sewage treatment plants.

The basic purpose was to define rheological
properties of the sludge. The experiments were conducted by using coaxial cylinder
with a rotating torque. The sludges had solid concentrations in the range of
1.04% to 6.56%.

The approximation was made after transforming
pseudo-curve obtained from the measurements into the true flow curve, made according
to the equation provided by Krieger, Elrod, Maron and ęvec. In order to describe
rheological characteristics, Herschel–Bulkleys' model was applied. The correlation
between rheological parameters (tauo, k, n) and gravimetric concentration
(Cs) was calculated.

The research has allowed the dimensioning
of the main transport installations for pumping sludge. Optimisation of the pump
discharge pressure, when transporting viscous sludge in pipelines is of the main
interest in wastewater industry.

The determination of rheological parameters,
especially yield stress (tauo), is important in sludge management,
including designed parameters in transporting, storing, spreading.

Key words: sewage sludge, rheology, apparent flow curve, rheological model.


Beata Malczewska
Institute of Environmental Engineering,
Wroc│aw University of Environmental and Life Sciences, Poland
Grunwaldzki Square 24, 50-365 Wroclaw, Poland
phone: +4871 3205519
email: beata.malczewska@up.wroc.pl

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.