Determination of some rheological parameters for the characterization of activated sludge

Tixier, Nicolas; Guibaud, Gilles; Baudu, Michel

doi:10.1016/s0960-8524(03)00109-3

Cited by 113 publications

(61 citation statements)

References 22 publications

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“…Among them, butyrate and acetate were the main products, accounting for 97% (W/W) of the total VFA and ethanol, suggesting a butyrate-type fermentation in this trail. Figure 3 shows a typical rheogram of the H 2 -producing sludge: its apparent viscosity (η app ) decreased rapidly as the shear rate increased, but became constant at a higher shear rate, which was called as the limiting viscosity (η ∞ ) at the infinite shear rate (Tixier et al, 2003). The limiting viscosity has been commonly used as a parameter for characterizing sludge rheology (Tixier et al, 2003).…”

Section: Fermentative H 2 Productionmentioning

confidence: 99%

“…Figure 3 shows a typical rheogram of the H 2 -producing sludge: its apparent viscosity (η app ) decreased rapidly as the shear rate increased, but became constant at a higher shear rate, which was called as the limiting viscosity (η ∞ ) at the infinite shear rate (Tixier et al, 2003). The limiting viscosity has been commonly used as a parameter for characterizing sludge rheology (Tixier et al, 2003). The limiting viscosity of the sludge changed slightly with the fermentation time in both trails (Fig.…”

Section: Fermentative H 2 Productionmentioning

confidence: 99%

“…4), at a level of 38 mPa s, suggesting invariable rheological characteristics of sludge in this H 2 -producing process. This might due to the fact that the experimental conditions, such as sludge concentration, pH, temperature and agitation rate, were kept unchanged in both trails (Tixier et al, 2003). …”

Section: Fermentative H 2 Productionmentioning

confidence: 99%

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Surface characteristics of acidogenic sludge in H2-producing process

Wang

Sheng

et al. 2007

J. of Wat. & Envir. Tech.

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The surface characteristics, including rheological, fractal characteristics, hydrophobicity as well as surface free energy, of H 2 -producing sludge in acidogenic fermentative process were investigated in this study. Both rheological and fractal characteristics of the H 2 -producing sludge changed slightly in the acidogenesis. The sludge fractal dimension was larger than those of other microbial aggregates, whereas the affinity of the microbial cells for the hydrocarbon had a peak value in the fermentation process. Both specific H 2 and volatile fatty acids/ethanol production rates of the sludge had a peak of 108 mL-and 480 mg L -1 h -1 g-VSS -1 . There was a relationship between the hydrophobicity of the H 2 -producing sludge and its specific H 2 -producing activity. The surface free energy of the H 2 -producing microorganisms had a lowest value in their growth process.

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Section: Fermentative H 2 Productionmentioning

confidence: 99%

Section: Fermentative H 2 Productionmentioning

confidence: 99%

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Surface characteristics of acidogenic sludge in H2-producing process

Wang

Sheng

et al. 2007

J. of Wat. & Envir. Tech.

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“…Appropriate treatment of wastewater as a result of efficient design and operation would help in environment protection and preservation [56]. This significance motivates the recent experimental investigations and mathematical modelling on activated sludge rheology and on the impact of rheological properties on operating parameters for conventional activated sludge plants (e.g., [57][58][59]) and for membrane bioreactors MBRs (e.g., [51,60,61]). …”

Section: Introductionmentioning

confidence: 96%

Rheology and Microbiology of Sludge from a Thermophilic Aerobic Membrane Reactor

Abbà

Collivignarelli

Manenti

et al. 2017

Journal of Chemistry

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A thermophilic aerobic membrane reactor (TAMR) treating high-strength COD liquid wastes was submitted to an integrated investigation, with the aim of characterizing the biomass and its rheological behaviour. These processes are still scarcely adopted, also because the knowledge of their biology as well as of the physical-chemical properties of the sludge needs to be improved. In this paper, samples of mixed liquor were taken from a TAMR and submitted to fluorescent in situ hybridization for the identification and quantification of main bacterial groups. Measurements were also targeted at flocs features, filamentous bacteria, and microfauna, in order to characterize the sludge. The studied rheological properties were selected as they influence significantly the performances of membrane bioreactors (MBR) and, in particular, of the TAMR systems that operate under thermophilic conditions (i.e., around 50 ∘ C) with high MLSS concentrations (up to 200 gTS L −1 ). The proper description of the rheological behaviour of sludge represents a useful and fundamental aspect that allows characterizing the hydrodynamics of sludge suspension devoted to the optimization of the related processes. Therefore, in this study, the effects on the sludge rheology produced by the biomass concentration, pH, temperature, and aeration were analysed.

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“…Therefore, the decrease of the floc structure in aerobic digestion was due to changes in environmental conditions caused by changes in the bacterial growth rate and their adaption to starvation conditions [30]. This is mainly due to the fact that small size solids provide more sites for cavitation [31] and exposes more particles to the resulting shear force [32,33]. Table 1 indicates that particle size is inversely proportional to the maximum substrate utilization rate of the microorganism [18].…”

Section: Mlss Mlvss Svi Cod and Do Profiles In Batch Experimentsmentioning

confidence: 99%

Evaluation of the Digestibility of Attached and Suspended Growth Sludge in an Aerobic Digester for a Small Community

Azizi

Kamika

Tekere

2018

Water

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Abstract:The aerobic sludge digestion process for waste sludge generated from suspended biomass (i.e., activated sludge process, ASP) and attached biomass (i.e., moving bed bioreactor, MBBR and modified packed bed biofilm, PBBR) reactors in a residential complex were analyzed. The rate of digestion with respect to different sludge characteristics generated through these various treatment processes were examined; the results revealed that waste sludge from ASP took 16 days to achieve complete digestion while MBBR and PBBR took nine and seven days, respectively. The most important factors influencing the sludge digestion such as sludge volume index (SVI), mixed liquor suspended solid (MLSS), and mixed liquor volatile suspended solid (MLVSS) were examined. The ASP which had the highest initial MLSS and MLVS took a longer time for digestion. Aerobic sludge digestion in all the treatment reactors was studied under laboratory scale conditions in batch experimentation to evaluate sludge characteristics and the rate of digestion as well as through a continuous bench scale pilot system to optimize the process parameters. Removal efficiencies of volatile solids (VS) 90.71% in ASP, 84.27% in MBBR and 84.07% in PBBR in aerobic digestion during batch mode were also observed. The study revealed that the aerobic sludge digestion process utilized in curbing sludge is not feasible application for a small community due to very long digestion times and a large amount of space although Packed Bed Biofilm (PBBR) used the lowest time (seven days) compared to the other systems.

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Determination of some rheological parameters for the characterization of activated sludge

Cited by 113 publications

References 22 publications

Surface characteristics of acidogenic sludge in H2-producing process

Surface characteristics of acidogenic sludge in H2-producing process

Rheology and Microbiology of Sludge from a Thermophilic Aerobic Membrane Reactor

Evaluation of the Digestibility of Attached and Suspended Growth Sludge in an Aerobic Digester for a Small Community

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