Effect of diffusion limitations and floc size distributions on fermentor performance and the interpretation of experimental data

1979 ◽  
Vol 21 (2) ◽  
pp. 221-251 ◽  
Author(s):  
B. Atkinson ◽  
F.-Ur- Rahman
Keyword(s):  
Experimental Data ◽  
Size Distributions ◽  
Floc Size ◽  
Diffusion Limitations ◽  
Floc Size Distributions

Modelling the activated sludge flocculation process combining laser light diffraction particle sizing and population balance modelling (PBM)

2002 ◽  
Vol 45 (6) ◽  
pp. 41-49 ◽  
Author(s):  
I. Nopens ◽  
C.A. Biggs ◽  
B. De Clercq ◽  
R. Govoreanu ◽  
B.-M. Wilén ◽  
...  
Keyword(s):  
Experimental Data ◽  
Laser Light ◽  
Population Balance ◽  
Light Diffraction ◽  
Balance Model ◽  
Floc Size ◽  
Shear Rates ◽  
Breakage Rate ◽  
On Line ◽  
Floc Size Distributions

A technique based on laser light diffraction is shown to be successful in collecting on-line experimental data. Time series of floc size distributions (FSD) under different shear rates (G) and calcium additions were collected. The steady state mass mean diameter decreased with increasing shear rate G and increased when calcium additions exceeded 8 mg/l. A so-called population balance model (PBM) was used to describe the experimental data. This kind of model describes both aggregation and breakage through birth and death terms. A discretised PBM was used since analytical solutions of the integro-partial differential equations are non-existing. Despite the complexity of the model, only 2 parameters need to be estimated: the aggregation rate and the breakage rate. The model seems, however, to lack flexibility. Also, the description of the floc size distribution (FSD) in time is not accurate.

Analysis of floc size distributions in a mixing tank

2008 ◽  
Vol 47 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Carole Coufort ◽  
Claire Dumas ◽  
Denis Bouyer ◽  
Alain Liné
Keyword(s):  
Size Distributions ◽  
Floc Size ◽  
Floc Size Distributions

Hydrodynamic conditioning of aluminium–bentonite flocs

2006 ◽  
Vol 6 (1) ◽  
pp. 11-19 ◽  
Author(s):  
C. Coufort ◽  
A. Liné
Keyword(s):  
Image Analysis ◽  
Size Distribution ◽  
High Sensitivity ◽  
Size Distributions ◽  
Hydrodynamic Stress ◽  
Floc Size ◽  
Micro Scale ◽  
Break Up ◽  
Floc Size Distributions

The aim of this paper is to analyse the role of hydrodynamics in flocculation. The effects of a hydrodynamic sequencing (flocculation–break-up–reflocculation–break-up–reflocculation) on the evolution of aluminium–bentonite floc size distributions and structure are investigated by image analysis in a Taylor–Couette reactor. The flocculation phenomena analysed in this study mainly occur in the viscous subrange, with floc size below the Kolmogorov micro-scale. The high sensitivity of steady-state floc size distribution to initial floc size distribution (elementary particles or flocs formed issuing break-up stages) is highlighted. Reversibility or irreversibility of agglomeration and break-up phenomena are discussed in terms of floc history and hydrodynamic stress. Finally, the hydrodynamic conditioning for aluminium–bentonite flocs is examined.

Characterization, fate and transport of floc aggregates in full-scale flocculation tanks

2016 ◽  
Vol 2 (1) ◽  
pp. 223-232 ◽  
Author(s):  
Yamuna S. Vadasarukkai ◽  
Graham A. Gagnon
Keyword(s):  
Fate And Transport ◽  
Full Scale ◽  
Size Distributions ◽  
Floc Size ◽  
Holographic Microscopy ◽  
Floc Size Distributions

In-line measurements of floc size distributions at different locations in a hydraulic flocculation tank using a holographic microscopy.

scholarly journals Characterization of Flocs and Floc Size Distributions Using Image Analysis

2016 ◽  
Vol 33 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Siwei Sun ◽  
Monroe Weber-Shirk ◽  
Leonard W. Lion
Keyword(s):  
Image Analysis ◽  
Size Distributions ◽  
Floc Size ◽  
Floc Size Distributions
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