A Model for Simultaneous Particulate and Dissolved Substrate Removal in a Biofilm Reactor

2006 ◽  
Vol 23 (5) ◽  
pp. 886-896 ◽  
Author(s):  
Joshua P. Boltz ◽  
Enrique J. La Motta
Keyword(s):  
Biofilm Reactor ◽  
Substrate Removal

scholarly journals Nitrogen removal from wastewater in an anoxic–aerobic biofilm reactor

2012 ◽  
Vol 2 (3) ◽  
pp. 165-174 ◽  
Author(s):  
M. F. Hamoda ◽  
R. A. Bin-Fahad
Keyword(s):  
Municipal Wastewater ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Fold Increase ◽  
Nitrogen Loading ◽  
Biofilm Reactor ◽  
Specific Substrate ◽  
Substrate Removal ◽  
Fixed Film ◽  
Oxidised Nitrogen

A pilot plant, using a four-compartment reactor packed with Biolace media, was operated in the anoxic/aerobic submerged fixed-film (A/ASFF) and the aerobic (ASFF) modes at loadings 0.03 to 0.3 g BOD. g−1 BVS. d−1, 0.01 to 0.11 g NH3. g−1 BVS d−1, HRTs 0.7 to 8 h, C/N of 6, and 28 ± 2 °C. The system proved to be very effective in treating municipal wastewater, achieving removals up to 98% for biological oxygen demand (BOD), 75% for chemical oxygen demand (COD) and 97% for ammonia. Performance was not adversely affected by a 10-fold increase in loading rate. Both modes of operation showed high specific nitrification rates up to 96 mg N. g−1 BVS d−1, but the A/ASFF was more stable and efficient at higher loadings. Its anoxic stage removed more than 90 and 60% for BOD and COD, respectively. The A/ASFF reactor also achieved denitrification, which eliminated 3.35 mg BOD (or 6.6 mg COD) versus 1 mg denitrified NO3-N, that resulted in higher organic removals. Denitrification rate increased linearly with the TON (total oxidised nitrogen) loading applied, and specific substrate removal reached up to 114 mg TON. g−1 BVS. d−1.

Significance of Spatial Distribution of Microbial Species in Mixed Culture Biofilms

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1365-1374 ◽  
Author(s):  
M. Fruhen ◽  
E. Christan ◽  
W. Gujer ◽  
O. Wanner
Keyword(s):  
Spatial Distribution ◽  
Mixed Culture ◽  
Biofilm Reactor ◽  
Constant Thickness ◽  
Nitrification Rate ◽  
Significant Shift ◽  
Bulk Fluid ◽  
Microbial Species ◽  
Substrate Removal ◽  
Biofilm Model

Experimental data from a biofilm reactor, in which two groups of organisms (Nitrifiers and Heterotrophs) compete for dissolved oxygen, were analyzed by a Mixed Culture Biofilm Model. The objective was to investigate to what extent and how fast relative abundance and spatial distribution of microbial species in a mixed culture biofilm changed upon variations of the bulk fluid substrate composition, and what the consequences of these changes were for substrate removal. Experimental results showed that within nine days the nitrification rate in a biofilm of constant thickness could change by a factor of five. Model predictions indicated that these changes must be due to a significant shift of the biofilm population. The distribution of the autotrophic and heterotrophic species over the depth of the biofilm turned out to be an important aspect of mixed culture biofilm behavior. Since it is difficult to observe the microbial population and its spatial distribution experimentally, the Mixed Culture Biofilm Model has proved to be a valuable tool for the interpretation of the observed phenomena.

Biofilm modeling with AQUASIM

2004 ◽  
Vol 49 (11-12) ◽  
pp. 137-144 ◽  
Author(s):  
O. Wanner ◽  
E. Morgenroth
Keyword(s):  
Plug Flow ◽  
Biofilm Reactor ◽  
Bulk Fluid ◽  
One Dimensional ◽  
Biofilm Thickness ◽  
Spatial Gradients ◽  
Biofilm Reactors ◽  
Microbial Species ◽  
Substrate Removal ◽  
Biofilm Modeling

AQUASIM is a computer program for the identification and simulation of aquatic systems. The program includes a one-dimensional multisubstrate and multispecies biofilm model and represents a suitable tool for biofilm simulation. The program can be used to calculate substrate removal in biofilm reactors for any user specified microbial system. One-dimensional spatial profiles of substrates and microbial species in the biofilm can be predicted. The program also calculates the development of the biofilm thickness and of the substrates and microbial species in the biofilm and in the bulk fluid over time. Detachment and attachment of microbial cells at the biofilm surface and in the biofilm interior can be considered, and simulations of sloughing events can be performed. Furthermore, AQUASIM allows pseudo two-dimensional modeling of plug flow biofilm reactors by a series of biofilm reactor compartments. The most significant limitation of the model is that it only considers spatial gradients of substrates and microbial species in the biofilm in the direction perpendicular to the substratum.

Modelling biofilm anaerobic reactor with effluent from hydrolytic/acidogenic reactor as substrate

2019 ◽  
Vol 79 (8) ◽  
pp. 1534-1540 ◽  
Author(s):  
Marisol Vergara Mendoza ◽  
Rodrigo Torres Sáez
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Biofilm Reactor ◽  
Methane Formation ◽  
Biofilm Thickness ◽  
Substrate Removal ◽  
Maximum Value ◽  
Degrading Bacteria ◽  
Acidogenic Reactor ◽  
Concentration Curves

Abstract This work presents modelling of an anaerobic biofilm reactor using ceramic bricks as support. The results were compared with the experimental data. It was observed that the substrate concentration curves showed the same tendency. The methane formation curves showed significant differences. The substrate removal efficiency was 83%. In the steady state, the experimental data were higher than the model, from the result the substrate degrading bacteria grew enough to reach biofilm and that the effect of the shear stress was more significant as the biofilm increased in thickness. To the methane production, the model in steady state reached a maximum value of 0.56 m3 CH4/m3 *d and the experimental data reached 0.42 (m3 CH4/m3 * d). The biofilm thickness calculated by the model was 14 μm.

Granular Activated Carbon Sequencing Batch Biofilm Reactor to Treat Problematic Wastewaters

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1195-1203 ◽  
Author(s):  
M. A. A. Jaar ◽  
P. A. Wilderer
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Biofilm Reactor ◽  
Adsorptive Capacity ◽  
Substrate Removal ◽  
Sequencing Batch Biofilm Reactor ◽  
Subsequent Decrease ◽  
Activated Carbon Filter ◽  
Micro Organisms ◽  
Carbon Filter

Experiments were conducted to study the performance of a reactor packed with granular activated carbon, and operated in a sequencing fill and draw mode. The reactor was inoculated with micro-organisms, loaded with a solution of 3-chlorobenzoate and thioglycolic acid. Oxygen was transfered to the microorganisms by means of silicon rubber tubings embedded in the activated carbon bed. Comparative studies were conducted with a continuous flow activated carbon filter and with a reactor packed with sand instead of granular activated carbon. Periodic operation of the granular activated carbon reactor provided superior results. High substrate removal efficiency was achieved as was high process stability under shock loading conditions, the latter mainly as a result of intermediate adsorption and subsequent decrease of toxic effects. After a period of 14 months of continuous operation the activated carbon had maintained about 90 per cent of its adsorptive capacity.

Chemical stress induced by copper: examination of a biofilm system

2006 ◽  
Vol 54 (9) ◽  
pp. 191-199 ◽  
Author(s):  
X. Zhang ◽  
K. Brussee ◽  
Caroline T. Coutinho ◽  
J.N. Rooney-Varga
Keyword(s):  
Extracellular Polymeric Substances ◽  
Wastewater Treatment Plants ◽  
Intergenic Spacer ◽  
Biofilm Reactor ◽  
Copper Removal ◽  
Reactor Performance ◽  
Copper Contamination ◽  
Substrate Removal ◽  
Contamination Levels ◽  
The Impact

Biofilm systems have been widely used in wastewater treatment plants. However, little information is available on the impact of toxic chemicals on the performance of fixed film systems. This study was aimed at evaluating the impact of copper on a biofilm system by examining a variety of parameters, including reactor pH, DO, substrate concentrations, secretion of extracellular polymeric substances (EPS), and copper removal and accumulation. The microbial communities in the biofilms were also examined using automated ribosomal intergenic spacer analysis (ARISA). Four rotating drum biofilm reactors were used to produce biofilms. One reactor was used to produce biofilms under copper free conditions; while the others were used to produce biofilms grown under three different copper contamination levels, namely 100 ppb, 200 ppb, and 500 ppb, for a prolonged period. The following results were obtained: (1) biofilm reactor performance was not significantly impacted as demonstrated by the pH, DO, substrate removal, and total solids in the effluent; (2) however, copper contamination inhibited EPS production in the biofilms; (3) copper removal efficiencies of 25–31% were obtained for the three copper contamination levels studied; (4) fixed films functionalized as a reservoir to accumulate more copper over time; and (5) copper contamination selected for specific species that were able to tolerate this stress and that may contribute to its remediation.

scholarly journals Performance evaluation and substrate removal kinetics in a thermophilic anaerobic moving bed biofilm reactor for starch degradation

2021 ◽  
Author(s):  
H. M. A. Shahzad ◽  
S. J. Khan ◽  
Z. Habib
Keyword(s):  
Second Order ◽  
Biofilm Reactor ◽  
Starch Degradation ◽  
Yield Coefficient ◽  
Moving Bed Biofilm Reactor ◽  
Order Model ◽  
Moving Bed ◽  
First Order ◽  
Substrate Removal ◽  
Second Order Model

Abstract A laboratory-scale anaerobic moving bed biofilm reactor (AnMBBR) was installed and operated at various hydraulic retention times (HRTs) of 20 to 1.5 d with surface area loading rate (SALR) of 0.86 to 11.43 gCOD/m2/d. Synthetic starch containing desizing wastewater with chemical oxygen demand (COD) of 12.75 g/L was prepared and fed into the reactor. Monod, modified Stover-Kincannon, Grau second-order and First-order substrate removal models were used to evaluate the results of AnMBBR. COD removal efficiency of bioreactor was dwindled by increasing the SALR or reducing the HRT. Decay coefficient (Kd) and yield coefficient (Y) for Monod model were 0.027 1/d and 1.01 mgVSS/mgCOD, respectively. Maximum substrate utilization rate (Umax) and kinetic constant (Kb) for Modified Stover-Kincannon model were estimated as 12.57 and 15.22 g/L/d, respectively. The constants (a and b) for Grau second-order model were found to be 1.09 and 1.31 whilst kinetic coefficient for Second-order model and First-order substrate removal model were 1.62 and 1.55 1/d, respectively. Modified Stover-Kincannon model and Grau second-order model were found to be the best fit for experimental data with R2 value of 0.99. The findings suggest that these models can be applied to predict the behaviour of AnMBBR on various scales.

Biofilm Structure – An Important and Neglected Parameter in Waste Water Treatment

1989 ◽  
Vol 21 (8-9) ◽  
pp. 805-814 ◽  
Author(s):  
F. R. Christensen ◽  
G. Holm Kristensen ◽  
J. la Cour Jansen
Keyword(s):  
Wastewater Treatment ◽  
Structural Changes ◽  
Waste Water Treatment ◽  
Experimental Investigations ◽  
Biofilm Reactors ◽  
Substrate Removal ◽  
Treatment Processes ◽  
Laboratory Reactor ◽  
Biofilm Structure ◽  
Kinetics Of

Experimental investigations on the kinetics of wastewater treatment processes in biofilms were performed in a laboratory reactor. Parallel with the kinetic experiments, the influence of the biofilm kinetics on the biofilm structure was studied at macroscopic and microscopic levels. The close interrelationship between biofilm kinetics and structural changes caused by the kinetics is illustrated by several examples. From the study, it is evident that the traditional modelling of wastewater treatment processes in biofilm reactors based on substrate removal kinetics alone will fail in many cases, due to the inevitable changes in the biofilm structure not taken into consideration. Therefore design rules for substrate removal in biofilms used for wastewater treatment must include correlations between the removal kinetics and the structure and development of the biological film.

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