Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

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INFLUENCE OF SEEDING CONDITIONS ON INITIAL BIOFILM DEVELOPMENT DURING THE STARTUP OF ANAEROBIC FLUIDIZED BED REACTORS

Water Pollution Research and Control Brighton ◽

10.1016/b978-1-4832-8439-2.50019-5 ◽

1988 ◽

pp. 157-165

Author(s):

F. Ehlinger ◽

J.M. Audic ◽

G.M. Faup

Keyword(s):

Fluidized Bed ◽

Fluidized Bed Reactors ◽

Biofilm Development ◽

Initial Biofilm

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Population dynamics of methanogenic biofilm consortium during a start-up period of anaerobic fluidized bed reactor

Water Science & Technology ◽

10.2166/wst.1994.0780 ◽

1994 ◽

Vol 29 (10-11) ◽

pp. 361-368 ◽

Cited By ~ 7

Author(s):

N. Araki ◽

H. Harada

Keyword(s):

Fluidized Bed ◽

Biofilm Formation ◽

Fluidized Bed Reactor ◽

Fluidized Bed Reactors ◽

Microbial Activities ◽

Acetate Production ◽

Biofilm Thickness ◽

Start Up ◽

Seed Sludge ◽

Initial Biofilm

The changes in physical properties and microbial activities were investigated during initial biofilm formation in lab-scale anaerobic fluidized bed reactors. Four different upflow velocities, i.e., 4, 7, 14 and 25 m·hr−1 were applied to four respective reactors of an equal size. The upflow velocities caused a prominent difference in the pattern of initial biofilm formation. The biofilm thickness attained eventually approximately 100 μm after 100 days of operation, independent of upflow velocity. On the contrary the biofilm density varied from 4.4 to 24.1 mg-VSS·cm−3 with an increase in the upflow velocity imposed. The activity of acetoclastic methane production increased remarkably 15 to 30 fold of seed sludge, regardless of upflow velocity. Microbial activities with respect to acetate production, H2-utilizing methanogenesis and acetate-utilizing methanogenesis increased finally up to 3-4 times as large as those of suspended grown sludge in a chemostat.

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Biofilm development during the start-up of a sulfate-reducing down-flow fluidized bed reactor at different COD/SO42− ratios and HRT

Water Science & Technology ◽

10.2166/wst.2011.701 ◽

2011 ◽

Vol 64 (4) ◽

pp. 910-916 ◽

Cited By ~ 7

Author(s):

E. Z. Piña-Salazar ◽

F. J. Cervantes ◽

M. Meraz ◽

L. B. Celis

Keyword(s):

Fluidized Bed ◽

Granular Sludge ◽

Fluidized Bed Reactor ◽

Sulfate Reducing ◽

Sulfate Removal ◽

Start Up ◽

Effective Removal ◽

Suspended Biomass ◽

High Sulfate ◽

Biofilm Development

In sulfate-reducing reactors, it has been reported that the sulfate removal efficiency increases when the COD/SO42− ratio is increased. The start-up of a down-flow fluidized bed reactor constitutes an important step to establish a microbial community in the biofilm able to survive under the operational bioreactor conditions in order to achieve effective removal of both sulfate and organic matter. In this work the influence of COD/SO42− ratio and HRT in the development of a biofilm during reactor start-up (35 days) was studied. The reactor was inoculated with 1.6 g VSS/L of granular sludge, ground low density polyethylene was used as support material; the feed consisted of mineral medium at pH 5.5 containing 1 g COD/L (acetate:lactate, 70:30) and sodium sulfate. Four experiments were conducted at HRT of 1 or 2 days and COD/SO42− ratio of 0.67 or 2.5. The results obtained indicated that a COD/SO42− ratio of 2.5 and HRT 2 days allowed high sulfate and COD removal (66.1 and 69.8%, respectively), whereas maximum amount of attached biomass (1.9 g SVI/L support) and highest sulfate reducing biofilm activity (10.1 g COD-H2S/g VSS-d) was achieved at HRT of 1 day and at COD/sulfate ratios of 0.67 and 2.5, respectively, which suggests that suspended biomass also played a key role in the performance of the reactors.

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Las degradation in a fluidized bed reactor and phylogenetic characterization of the biofilm

Brazilian Journal of Chemical Engineering ◽

10.1590/s0104-66322013000300010 ◽

2013 ◽

Vol 30 (3) ◽

pp. 521-529 ◽

Cited By ~ 10

Author(s):

L. L. Oliveira ◽

R. B. Costa ◽

I. K. Sakamoto ◽

I. C. S. Duarte ◽

E. L. Silva ◽

...

Keyword(s):

Fluidized Bed ◽

Fluidized Bed Reactor ◽

Phylogenetic Characterization

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CHARACTERIZATION OF FLUIDIZED BED REACTORS WITH GAS TRACER MEASUREMENTS

Chemical Engineering Communications ◽

10.1080/00986448108910942 ◽

1981 ◽

Vol 10 (4-5) ◽

pp. 307-330 ◽

Cited By ~ 7

Author(s):

D. WIPPERN ◽

K. WITTMANN ◽

J. KÜHNE ◽

H. HELMRICH ◽

K. SCHÜGERL

Keyword(s):

Fluidized Bed ◽

Fluidized Bed Reactors ◽

Gas Tracer

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Anaerobic treatment of low concentration waste water in an inverse fluidized bed reactor

Water Science & Technology ◽

10.2166/wst.2000.0452 ◽

2000 ◽

Vol 41 (4-5) ◽

pp. 245-251 ◽

Cited By ~ 17

Author(s):

P. Castilla ◽

M. Meraz ◽

O. Monroy ◽

A. Noyola

Keyword(s):

Fluidized Bed ◽

Removal Efficiency ◽

Suspended Solids ◽

Municipal Wastewater ◽

Specific Activity ◽

Biomass Concentration ◽

Fluidized Bed Reactor ◽

Anaerobic Treatment ◽

Low Concentration ◽

Inverse Fluidized Bed

Low concentration synthetic and municipal wastewaters were treated at HRT as short as 3 and 0.6 h respectively in an anaerobic inverse fluidized bed. Both bioreactors showed gas hold up due to the liquid downflow pattern of the prototype. The bioreactor operated at 3 h had a removal efficiency of 83%, specific activity of 4.5 kg CODremoved/kg IVS (d and the gas hold up varied from 23 to 55%. The reactor treating municipal wastewater had a removal efficiency of 44% when operating at 0.6 h, the specific activity was 4.2 kg CODremoved/kg IVS (d and no biogas was detected apparently because an important fraction was dissolved in the liquid phase. The biomass concentration was 13.8 and 1.1 kg IVS/m3 for synthetic and municipal wastewater and the SEM microphotographs showed a bacterial diversity for the first run and only cocci cells for the second run. The system does not remove suspended solids, so a polishing postreatment to improve water quality has to be implemented.

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