Use of image analysis and rheological studies for the control of settleability of filamentous bacteria: application in SBR reactor

Dagot, Christophe; Pons, Marie‐Noëlle; Casellas, Magali; Guibaud, Gilles; Dollet, P.; Baudu, Michel

doi:10.2166/wst.2001.0115

Cited by 21 publications

(8 citation statements)

References 16 publications

(13 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…shear stress (t) exerted on the sludge is not proportional to the induced shear rate (g ) and behaviour is often a time dependant process [17]. Filaments in excess confer a thixotropic character on sludge that is possible to detect under certain experimental conditions [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Hysteresis area, a rheological parameter used as a tool to assess the ability of filamentous sludges to settle

Guibaud¹,

Tixier²,

Baudu³

2005

Process Biochemistry

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Hysteresis area, a rheological parameter used as a tool to assess the ability of filamentous sludges to settle

Guibaud¹,

Tixier²,

Baudu³

2005

Process Biochemistry

View full text Add to dashboard Cite

“…Rheology should provide an interesting tool in sewage sludge management [18,19]. Rheological characteristics have been used for the improvement of processes or in the operation of sludge conditioning and dewatering [20,21].…”

Section: Introductionmentioning

confidence: 99%

Effect of ph and ionic environment changes on interparticle interactions affecting activated sludge flocs: A rheological approach

Tixier

Guibaud

Baudu

2003

Environmental Technology

Self Cite

View full text Add to dashboard Cite

The rheological behaviour of activated sludge was investigated through the determination of sludge suspension equilibrium viscosity (micro(eq)) while varying the pH, sodium chloride and calcium chloride concentrations over a wide range. Micro(eq) was used to investigate the influence of environmental changes on the rheological behaviour of activated sludges, on the basis that it is representative of interparticle interactions affecting sludge flocs. Micro(eq) was shown to increase with increasing pH and to decrease with cation addition. The surface charge presented by sludge flocs was shown to be a factor that greatly affects micro(eq), as demonstrated by the linear correlation with zeta-potential (zeta-potential). A decrease in electrostatic charge was supposed to decrease repulsive effect between particles that facilitate flow and to promote a compaction of flocs that lower viscosity. Cation addition was shown to generate a viscosity decrease, in the same proportion, independent of the valency of the cation. The decrease in the particles double layer thickness coupled to the decrease in surface charge were supposed to induce a decrease in interparticle interactions which leads to lower viscosity values.

show abstract

“…Bulking can be caused by both filamentous and non-filamentous factors, affecting in different ways the sludge settling ability which can be detected by image analysis methodologies [4,[6][7][8][9][10][11][12]. The combination of settling properties and the parameters obtained from image analysis may offer powerful information enabling immediate interventions on the biological system.…”

Section: Introductionmentioning

confidence: 99%

Correlation between sludge settling ability and image analysis information using partial least squares

Mesquita

Dias

et al. 2009

Analytica Chimica Acta

View full text Add to dashboard Cite

In the last years there has been an increase on the research of the activated sludge processes, and mainly on the solid-liquid separation stage, considered of critical importance, due to the different problems that may arise affecting the compaction and the settling of the sludge. Furthermore, image analysis procedures are, nowadays considered to be an adequate method to characterize both aggregated and filamentous bacteria, and increasingly used to monitor bulking events in pilot plants. As a result of that, in this work, image analysis routines were developed in Matlab environment, allowing the identification and characterization of microbial aggregates and protruding filaments. Moreover, the large amount of activated sludge data collected with the image analysis implementation can be subsequently treated by multivariate statistical procedures such as PLS. In the current work the implementation of image analysis and PLS techniques has shown to provide important information for better understanding the behavior of activated sludge processes, and to predict, at some extent, the sludge volume index. As a matter of fact, the obtained results allowed explaining the strong relationships between the sludge settling properties and the free filamentous bacteria contents, aggregates size and aggregates morphology, establishing relevant relationships between macroscopic and microscopic properties of the biological system.

show abstract

Use of image analysis and rheological studies for the control of settleability of filamentous bacteria: application in SBR reactor

Cited by 21 publications

References 16 publications

Hysteresis area, a rheological parameter used as a tool to assess the ability of filamentous sludges to settle

Hysteresis area, a rheological parameter used as a tool to assess the ability of filamentous sludges to settle

Effect of ph and ionic environment changes on interparticle interactions affecting activated sludge flocs: A rheological approach

Correlation between sludge settling ability and image analysis information using partial least squares

Contact Info

Product

Resources

About