Factors Influencing Formation and Maintenance of Granules in Anaerobic Sludge Blanket Reactors (UASBR)

1990 ◽  
Vol 22 (9) ◽  
pp. 275-282 ◽  
Author(s):  
N. Kosaric ◽  
R. Blaszczyk ◽  
L. Orphan
Keyword(s):  
Loading Rate ◽  
Gas Production ◽  
Anaerobic Sludge ◽  
Hydrodynamic Conditions ◽  
Bed Height ◽  
Factors Influencing ◽  
Volumetric Loading ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors ◽  
Granule Growth

Four, 20 L UASB reactors were operated under different hydrodynamic regimes continuously for more than 150 days. The influence of superficial liquid upflow velocities over the range 0.2 5 to 1.5 m h−1, on granule activity and characteristics was investigated, maintaining constant temperature (35°C), and volumetric loading rate (6.2 g COD L−1 day−1). Reactor pH, COD removal, VFA concentration, bed height and gas production were continuously monitored and evaluated. It was found that hydrodynamic conditions can influence the size of granules, and their settling characteristics. Low upflow velocities (0.25 and 0.5 m h−1), are favourable for granule growth and accumulation. At high upflow velocities (1.0 and 1.5 m h−1), no sludge accumulation and disintegration of larger granules were observed.

Methanogenic granule development in full scale internal circulation reactors

1994 ◽  
Vol 30 (8) ◽  
pp. 9-21 ◽  
Author(s):  
J. H. F. Pereboom ◽  
T. L. F. M. Vereijken
Keyword(s):  
Loading Rate ◽  
Gas Production ◽  
Full Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Internal Circulation ◽  
Methanogenic Activity ◽  
Average Shear ◽  
Biomass Retention ◽  
Uasb Reactors

Internal Circulation (IC) reactors can be operated at higher reactor volume loading rates than Upflow Anaerobic Sludge Blanket (UASB) reactors. This results in increased gas production rates and subsequently higher average shear rates in IC-reactors. Furthermore, the liquid upflow velocity is 8-20 times higher, still granules develop successfully in IC-reactors. To investigate the granule development in IC-reactors and elucidate the process limitations with respect to granule development and biomass retention, granule samples from three full scale IC-reactors are characterized. Characterization included size distribution, strength, settling velocity, density, ash content and methanogenic activity. Granules were compared with samples from UASB reactors treating similar types of wastewaters. A hydrodynamic model was developed to describe the liquid circulation in IC reactors. The average shear rate in IC reactors is approximately twice as high compared to UASB-reactors. The two stage design of the IC-reactor allows 3-6 times higher loading rate. The experimental results showed that IC-granules are larger than UASB-granules grown on similar wastewater, while the strength of IC-granules is lower as a result of the higher sludge loading rate. Although wash-out is slightly enhanced in IC-reactors, the conditions in the second stage are tranquil enough to ensure adequate biomass retention in IC-reactors. The development of characteristic IC-granules after seeding proceeds within a few months. Physical characteristics of granules are determined mainly by biological factors.

The use of upflow anaerobic sludge blanket reactors in the treatment of poultry slaughterhouse wastewater

2001 ◽  
Vol 44 (4) ◽  
pp. 83-88 ◽  
Author(s):  
V. Del Nery ◽  
M. H.Z. Damianovic ◽  
F. G. Barros
Keyword(s):  
Loading Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Dissolved Air Flotation ◽  
Slaughterhouse Wastewater ◽  
Cod Reduction ◽  
Start Up ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

This work studied the performance of the dissolved air flotation (DAF) system and the start-up and the operation of two 450 m3 UASB reactors in a poultry slaughterhouse in Sorocaba, Brazil. The DAF presented reduction efficiency of grease and fats, suspended solids and COD 50% higher. The reactors were seeded with non-adapted sludge. The average COD of the reactor influent was 2,695mg/L; and the initial organic loading rate (OLR) and the initial sludge loading rate at the start-up were 0.51 kg COD/m3.day and 0.04 kg COD/kg VTS.day, respectively. The start-up period was 144 days. During this time the reactor flow rate and OLR were gradually increased. At the reactor start-up, the maximum OLR value was 2.1 kg COD/m3.day, the COD reduction was higher than 80%, and the concentration of volatile fatsty acids (VFA) was below 100mg/L. The COD reductions, considering the reactor effluent raw COD and soluble COD were similar throughout the period studied in both reactors. The reactor effluent raw COD was approximately 10% higher than the soluble COD until the 225th day of operation. From the 225th day of operation this value increased 20%-30% due to the sludge washout. The effluent soluble COD reduction, the effluent VFA concentration and the operational stability attested the good performance of UASB reactors in poultry slaughterhouse wastewater treatment.

Combined UASB reactor and DAF/BF/anoxic/aerobic process for the removal of high-concentration organic matter and nutrients from slurry-type swine waste

2004 ◽  
Vol 49 (5-6) ◽  
pp. 199-205 ◽  
Author(s):  
B.U. Kim ◽  
C.H. Won ◽  
J.M. Rim
Keyword(s):  
Loading Rate ◽  
Removal Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Swine Waste ◽  
High Concentration ◽  
Dissolved Air Flotation ◽  
Volumetric Loading ◽  
Anaerobic Sludge Blanket ◽  
Dissolved Air

This research aimed to effectively remove high-concentration organic matter and nutrients from slurry-type swine waste using a combined upflow anaerobic sludge blanket reactor with the dissolved air flotation/aerobic submerged biofilm/anoxic/aerobic process. The upflow anaerobic sludge blanket reactor was operated at an organics volumetric loading rate of 3.2Ð6.1 kg COD/m3/day, and the removal rates of COD were 53.9-65.5%. The removal rate of COD of the overall process was more than 99%. In the aerobic submerged biofilm, over 95% of ammonium nitrogen was removed at a volumetric loading rate of 0.08-0.16 kg NH4+-N/m3/day. The specific denitrification rate was 0.257 g NO3-N/g MLVSS/day and the removal rate of total nitrogen was 86.7%. Phosphorus was removed by flocculation in the dissolved air flotation process, and 0.16 g of PO4-P was removed by 1 g of ferric ion.

Effect of Nitrogen Loading Rate and Carbon Source on Denitrification and Sludge Settleability in Upflow Anaerobic Sludge Blanket (UASB) Reactors

1999 ◽  
Vol 40 (8) ◽  
pp. 123-130 ◽  
Author(s):  
F. M. Cuervo-López ◽  
F. Martinez ◽  
M. Gutiérrez-Rojas ◽  
R. A. Noyola ◽  
J. Gómez
Keyword(s):  
Carbon Source ◽  
Loading Rate ◽  
Carbon Sources ◽  
Nitrogen Loading ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Reactor Stability ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors ◽  
Sludge Settleability

The combined effect of carbon source and nitrogen loading rate (NLR) on denitrification and sludge granular settleability in upflow anaerobic sludge blanket (UASB) bench-scale reactors was studied. Acetate, lactate and glucose were used as carbon sources for denitrification. Three NLR were evaluated: 500, 1000 and 2000 mg NO3−-N/ld. It was found that NO3−-N consumption efficiency was 99% for all the cases. Denitrification efficiencies were high (85-96%) for all substrates and NLR tested, but specific denitrifying rates were a better representation of the denitrifying process. The results showed that specific denitrifying rate was dependent on type of carbon source and NLR. It was also found that sludge settleability and reactor stability was influenced by the carbon source. The use of acetate did not influence the sludge settleability while, sludge flotation was always observed when lactate was used as carbon source. Foaming was present when glucose was used, causing reactor unstability. An increase in the exopolymeric protein and carbohydrate content was observed when lactate and glucose were fed, in comparison with acetate as carbon source. Results obtained in this work suggest that the exopolymeric composition here referred to as protein/carbohydrate ratio (P/C) could be a better stability indicator than the sludge volumetric index (SVI).

A new model for anaerobic processes of up-flow anaerobic sludge blanket reactors based on cellular automata

2002 ◽  
Vol 45 (10) ◽  
pp. 87-92 ◽  
Author(s):  
I.V. Skiadas ◽  
B.K. Ahring
Keyword(s):  
Cellular Automata ◽  
Loading Rate ◽  
Layer Structure ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Operational Parameters ◽  
Microbial Composition ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

The advantageous performance of the UASB reactors is due to the immobilisation of the active biomass, since bacteria coagulate forming aggregates usually called granules. Changes in organic loading rate, hydraulic loading rate or influent substrate composition usually result in changes in granule characteristics and lead to different reactor behaviour. A dynamic mathematical model has been developed for the anaerobic digestion of a glucose based synthetic wastewater in UASB reactors. Cellular automata (CA) theory has been applied to simulate the granule development process. The model takes into consideration that granule diameter and granule microbial composition are functions of the reactor operational parameters and is capable of predicting the UASB performance and the layer structure of the granules.

Biomass Acclimatization to Sequentially Varying Substrates in an Upflow Anaerobic Sludge Blanket (UASB) Bioreactor

2006 ◽  
Vol 41 (4) ◽  
pp. 437-448 ◽  
Author(s):  
Yee Ying Jennifer Tan ◽  
Mohd. Ali Hashim ◽  
K.B. Ramachandran
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Domestic Wastewater ◽  
High Strength ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Start Up ◽  
Time Required ◽  
Volumetric Loading ◽  
Anaerobic Sludge Blanket

Abstract In this study, an upflow anaerobic sludge blanket (UASB) bioreactor was sequentially subjected to high-strength synthetic, low-strength synthetic and domestic wastewaters. From COD removal data, supported by volumetric loading rate, hydraulic retention time, pH and qualitative biogas production data, it was observed that the biomass in the bioreactor took about twice the time required to acclimatize to a change in substrate characteristics or composition compared to a much more drastic quantitative change, i.e., more than 95% difference, in substrate concentration. As the initial experiment coincided with the bioreactor start-up, it could also be concluded that the feeding regime did not shorten the overall start-up time of a UASB bioreactor meant to treat domestic wastewater, but its eventual success was probably more assured.

Improved nitrogen removal in upflow anaerobic sludge blanket (UASB) reactors by incorporation of Anammox bacteria into the granular sludge

2004 ◽  
Vol 49 (11-12) ◽  
pp. 69-76 ◽  
Author(s):  
J.E. Schmidt ◽  
D.J. Batstone ◽  
I. Angelidaki
Keyword(s):  
In Situ Hybridisation ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
Appropriate Technology ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
The Third ◽  
Anammox Activity ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Upflow anaerobic sludge blanket reactors may offer a number of advantages over conventional mixed-tank, SBR, and biofilm reactors, including high space-loading, low footprint, and resistance to shocks and toxins. In this study, we assessed the use of upflow anaerobic sludge blanket (UASB) reactor technology as applied to anaerobic ammonia removal, or Anammox. Four 200 ml UASB reactors were inoculated with 50% (by volume) anaerobic granular sludge and 50% flocular sludge from different sources (all with the potential for containing Anammox organisms). Tools used to assess the reactors included basic analyses, fluorescent in-situ hybridisation, and mathematical modelling, with statistical non-linear parameter estimation. Two of the reactors showed statistically identical Anammox activity (i.e., identical kinetic parameters), with good ammonia and nitrite removal (0.14 kgNHx m-3 reactor day-1, with 99% ammonia removal). The third reactor also demonstrated significant Anammox activity, but with poor identifiability of parameters. The fourth reactor had no statistical Anammox activity. Modelling indicated that poor identifiability and performance in the third and fourth reactors were related to an excess of reduced carbon, probably originating in the inoculum. Accumulation of Anammox organisms was confirmed both by a volume loading much lower than the growth rate, and response to a probe specific for organisms previously reported to mediate Anammox processes. Overall, the UASB reactors were effective as Anammox systems, and identifiability of the systems was good, and repeatable (even compared to a previous study in a rotating biological contactor). This indicates that operation, design, and analysis of Anammox UASB reactors specifically, and Anammox systems in general, are reliable and portable, and that UASB systems are an appropriate technology for this process.

scholarly journals The Concept of Wastes to Energy Using Sugary Wastes

2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Sugar Mills ◽  
Anaerobic Sludge Blanket

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62

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