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

2011 ◽  
Vol 64 (4) ◽  
pp. 910-916 ◽  
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.

Population dynamics of biofilm development during start-up of a butyrate-degrading fluidized-bed reactor

1991 ◽  
Vol 36 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Gerhard Zellner ◽  
Michael Geveke ◽  
Everly Conway de Macario ◽  
Hans Diekmann
Keyword(s):  
Population Dynamics ◽  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Start Up ◽  
Biofilm Development

Characterization of sulfate-reducing bacteria dominated surface communities during start-up of a down-flow fluidized bed reactor

2008 ◽  
Vol 36 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Lourdes B. Celis ◽  
Denys Villa-Gómez ◽  
Angel G. Alpuche-Solís ◽  
B. Otto Ortega-Morales ◽  
Elías Razo-Flores
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Sulfate Reducing Bacteria ◽  
Sulfate Reducing ◽  
Start Up ◽  
Reducing Bacteria

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

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

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.

Kinetics of an anaerobic fluidized bed reactor using biolite carrier

1996 ◽  
Vol 23 (6) ◽  
pp. 1305-1315 ◽  
Author(s):  
R. Prakash ◽  
K. J. Kennedy
Keyword(s):  
Steady State ◽  
Fluidized Bed ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Loading Rates ◽  
Start Up ◽  
Removal Efficiencies ◽  
Biofilm Development ◽  
Kinetics Of

Start-up and steady state operation of anaerobic fluidized bed reactors (AFBRs) with biolite as the inert carrier material was studied. Start-up and concomitant biofilm development of AFBRs was performed using two common start-up techniques, the maximum efficiency profile (MEP) technique and the maximum load profile (MLP) technique. The MEP start-up technique increases the volumetric organic loading rates to the reactor gradually and is tied to the removal efficiency of the process. The MLP start-up technique maintains a moderately high but constant volumetric organic loading rate irrespective of reactor performance. Using sucrose-based wastewater as feed, both start-up techniques led to equally fast biofilm development and start-up times of approximately 5 weeks. However, the MEP technique resulted in more stable controlled reactor operation during the start-up period. The quick start-up confirms the high compatibility of biolite for bio-adhesion and the development of a healthy active biofilm.High concentrations of biofilm biomass achieved in AFBRs (69 g volatile biofilm solids (VBS)/L of expanded bed volume at an organic loading rate of 25 g COD/(Lùd)) allowed the successful treatment of wastewaters at high organic loading rates and organic removal efficiencies. During steady state experiments, organic removal efficiencies over 80% were obtained for organic loading rates as high as 20 g COD/(L∙d). It was found that the dependence of removal efficiency on hydraulic retention time is influenced by substrate concentration. Total biofilm yield was determined to be 0.08 g VBS/g COD removed, demonstrating the low net synthesis of solids in the AFBR. AFBRs had an average solids retention time of 150 days, corresponding to a washout factor of 0.01. Extrinsic kinetics of the AFBRs was determined to be zero order with a maximum specific utilization rate of 0.48 g COD/(g VBS∙d).AFBRs used to treat municipal landfill leachate with a BOD5:COD ratio of 0.86 achieved steady state COD removal efficiencies that ranged from 70% to 87%, depending on the reactor organic loading rate and the concentration of the leachate being treated. During leachate treatment, biofilm biomass gradually became "mineralized" as a result of precipitation of metal sulfides and carbonates. This eventually resulted in a decrease in biofilm microbial activity and the need for higher pumping rates to maintain the same degree of bed expansion. Key words: anaerobic, biological fluidized bed reactor, biolite, landfill leachate, sucrose, modeling, start-up, steady state kinetics.

Anaerobic treatment of sulfate-containing municipal wastewater with a fluidized bed reactor at 20 °C

2016 ◽  
Vol 73 (10) ◽  
pp. 2446-2452 ◽  
Author(s):  
B. Düppenbecker ◽  
P. Cornel
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Fluidized Bed Reactor ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Sulfate Reducing ◽  
Mass Flows ◽  
Reducing Bacteria

This study focuses on the anaerobic treatment of sulfate-containing municipal wastewater at 20 °C with a fluidized bed reactor. Mean influent chemical oxygen demand (COD) and sulfate concentrations were 481 and 96 mg/l. The response of the COD removal efficiency to increasing organic loading rates (OLR) was investigated. Average total COD removal was 61% at OLR between 2.7 and 13.7 kg COD/(m³·d) and did not distinctly depend on the OLR. To assess the removal efficiency in more detail the COD in- and output mass flows were balanced. The results showed that only 11–12% of the input COD was recovered as gaseous methane. About 12–13% of the input COD remained in the effluent as dissolved methane. Furthermore, a distinct amount of 12–19% of the input COD remained in the reactor as settled sludge and was not further biologically degraded. Due to the reduction by sulfate-reducing bacteria, 13–14% of the input COD was degraded. Further adverse impacts of the influent sulfate on the anaerobic treatment process are discussed as well.

A Syntrophic Propionate-Oxidizing, Sulfate-Reducing Bacterium from a Fluidized Bed Reactor

1996 ◽  
Vol 19 (3) ◽  
pp. 414-420 ◽  
Author(s):  
Gerhard Zellneri ◽  
Annette Busmann ◽  
Fred A. Rainey ◽  
Hans Diekmann
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Sulfate Reducing

Start-up and operation of a propionate-degrading fluidized-bed reactor

1992 ◽  
Vol 36 (6) ◽  
Author(s):  
Birgit Heppner ◽  
Gerhard Zellner ◽  
Hans Diekmann
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Start Up
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