Fluidization and reactor biomass characteristics of the denitrification fluidized bed biofilm reactor

By maintaining the same operational conditions of one conventional¯uidized-bed bioreactor (CFB) and two tapered¯uidized-bed bioreactors (TFBs), the performance of the TFBs with taper angles of 5°and 2.5°were found to be superior to that of the CFB with a taper angle of 0°. Experimental results together with statistical analyses showed that the bioparticle and hydrodynamic characteristics of the TFBs were signi®cantly different from those of the CFB. Also, bioparticle strati®cation occurred in the three bioreactors. The bio®lm thickness (d) and the speci®c biomass (b) of the three bioreactors varied in the following decreasing order 5°b 2.5°b 0°under the same volumetric loading. Meanwhile, the speci®c energy dissipation rate (v) and the bioparticle washout rates (W = 0.214 AE 0.219; 0.537 AE 0.493 g BAC dm

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“…) obtained by Mulcahy and Shieh,15 who used glass beads in a¯uidized-bed bioreactor to conduct a denitri®cation study.…”

Section: à3mentioning

confidence: 99%

Comparative bioparticle and hydrodynamic characteristics of conventional and tapered anaerobic fluidized-bed bioreactors

Huang

Yan

2000

J. Chem. Technol. Biotechnol.

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“…Based on experiment, the proposed equations by Ro 7 and Mulcahy 6 to determine the wet and dry biofilm densities respectively were found the most suitable among the literature equations. A terminal velocity test for biofilm-coated particles was conducted.…”

Section: Discussionmentioning

confidence: 99%

“…The literature equations were not adequate for Re t [ 130. A new explanation of drag coefficient for a wide range of Re t and based on a biofilm-coated particle Archimedes number, a new equation was generated that was able to predict terminal settling velocity with average error of 5.9 AE 4.6%, 11.1 AE 8.4%, 9.5 AE 6.5%, 7.6 AE 5.3%, 8.8 AE 4.8%, and 10.8 AE 2.5% for this work, Nicolella, 10 Mulcahy, 6 Hermaniwicz, 5 Csikor, 21 and Turan,23 respectively. This equation is explicit in terminal settling velocity and is valid within 310 \ Ar \ 2.5 Â 10 5 and 7 \ Re t \ 300.…”

Section: Discussionmentioning

confidence: 99%

“…In this figure, it can be clearly seen that the calculated terminal velocities closely match the experimental data from different researchers. Compared to all experimental data, this equation predicted the terminal velocities with average errors 5.9 AE 4.6%, 11.1 AE 8.4%, 9.5 AE 6.5%, 7.6 AE 5.3%, 8.8 AE 4.8%, and 10.8 AE 2.5% for this work, Nicolella, 10 Mulcahy, 6 Hermaniwicz, 5 Csikor, 21 and Turan, 23 respectively. To compare, equation suggested by Nicolella 10 , as the most previously reliable equation for biofilm particles, predict the terminal velocities with errors of 37.9 AE 7.6%, 8.45 AE 6.6%, 11.2 AE 7.6%, 9.4 AE 9.6%, 9.4 AE 9.5%, and 18.1 AE 2.8% for this work, Nicolella, 10 Mulcahy, 6 Hermaniwicz, 5 Csikor, 21 and Turan, 22 respectively.…”

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confidence: 95%

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Terminal settling velocity and drag coefficient of biofilm‐coated particles at high Reynolds numbers

2010

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The drag force (F d ) on bio-coated particles taken from two laboratory-scale liquidsolid circulating fluidized bed bioreactors (LSCFBBR) was studied. The terminal velocities (u t ) and Reynolds numbers (Re t ) of particles observed were higher than reported in the literature. Literature equations for determining u t were found inadequate to predict drag coefficient (C d ) in Re t [ 130. A new equation for determining F d as an explicit function of terminal settling velocity was generated based on Archimedes numbers (Ar) of the biofilm-coated particle. The proposed equation adequately predicted the terminal settling velocity of other literature data at lower Re t of less than 130, with an accuracy [85%.

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“…In fluidized bed bioreactors, t U and n are biofilm thickness functions. Authors (Hermanowicz and Ganzarczyk, 1983;Mulcahy and Shieh, 1987;Ngian and Marti, 1980;Setiadi, 1995;Thomas and Yates, 1985;Yu and Rittmann, 1997) have studied the effects of biofilm accumulation on these parameters in fluidized bed reactors. However, better concordance between experimental and predicted hydrodynamic values was obtained using the correlation formulated by Foscolo et al (1983), even though it was not deduced to describe the hydrodynamics of AFBRs (Abdul-Aziz and Asolekar, 2000).…”

Section: Bioparticle Model and Fluidization Characteristicsmentioning

confidence: 99%

Experimental and theoretical investigation of anaerobic fluidized bed biofilm reactors

Fuentes¹,

Mussati²,

Aguirre³

et al. 2009

Braz. J. Chem. Eng.

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-This work presents an experimental and theoretical investigation of anaerobic fluidized bed reactors (AFBRs). The bioreactors are modeled as dynamic three-phase systems. Biochemical transformations are assumed to occur only in the fluidized bed zone. The biofilm process model is coupled to the system hydrodynamic model through the biofilm detachment rate; which is assumed to be a first-order function of the energy dissipation parameter and a second order function of biofilm thickness. Non-active biomass is considered to be particulate material subject to hydrolysis. The model includes the anaerobic conversion for complex substrate degradation and kinetic parameters selected from the literature. The experimental set-up consisted of two mesophilic (36±1ºC) labscale AFBRs (R1 and R2) loaded with sand as inert support for biofilm development. The reactor start-up policy was based on gradual increments in the organic loading rate (OLR), over a four month period.Step-type disturbances were applied on the inlet (glucose and acetic acid) substrate concentration (chemical oxygen demand (COD) from 0.85 to 2.66 g L -1) and on the feed flow rate (from 3.2 up to 6.0 L d -1 ) considering the maximum efficiency as the reactor loading rate switching. The predicted and measured responses of the total and soluble COD, volatile fatty acid (VFA) concentrations, biogas production rate and pH were investigated. Regarding hydrodynamic and fluidization aspects, variations of the bed expansion due to disturbances in the inlet flow rate and the biofilm growth were measured. As rate coefficients for the biofilm detachment model, empirical values of

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Fluidization and reactor biomass characteristics of the denitrification fluidized bed biofilm reactor

Cited by 66 publications

References 8 publications

Comparative bioparticle and hydrodynamic characteristics of conventional and tapered anaerobic fluidized-bed bioreactors

Comparative bioparticle and hydrodynamic characteristics of conventional and tapered anaerobic fluidized-bed bioreactors

Terminal settling velocity and drag coefficient of biofilm‐coated particles at high Reynolds numbers

Experimental and theoretical investigation of anaerobic fluidized bed biofilm reactors

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