scholarly journals Up-Flow Anaerobic Sludge Blanket (UASB) Technology for Energy Recovery: A Review on State-of-the-Art and Recent Technological Advances

2020 ◽  
Vol 7 (2) ◽  
pp. 43 ◽  
Author(s):  
Matia Mainardis ◽  
Marco Buttazzoni ◽  
Daniele Goi
Keyword(s):  
Circular Economy ◽  
Microbial Community Composition ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Fatty Acid Production ◽  
Modeling Tools ◽  
Biogas Yield ◽  
Anaerobic Sludge Blanket

Up-flow anaerobic sludge blanket (UASB) reactor belongs to high-rate systems, able to perform anaerobic reaction at reduced hydraulic retention time, if compared to traditional digesters. In this review, the most recent advances in UASB reactor applications are critically summarized and discussed, with outline on the most critical aspects for further possible future developments. Beside traditional anaerobic treatment of soluble and biodegradable substrates, research is actually focusing on the treatment of refractory and slowly degradable matrices, thanks to an improved understanding of microbial community composition and reactor hydrodynamics, together with utilization of powerful modeling tools. Innovative approaches include the use of UASB reactor for nitrogen removal, as well as for hydrogen and volatile fatty acid production. Co-digestion of complementary substrates available in the same territory is being extensively studied to increase biogas yield and provide smooth continuous operations in a circular economy perspective. Particular importance is being given to decentralized treatment, able to provide electricity and heat to local users with possible integration with other renewable energies. Proper pre-treatment application increases biogas yield, while a successive post-treatment is needed to meet required effluent standards, also from a toxicological perspective. An increased full-scale application of UASB technology is desirable to achieve circular economy and sustainability scopes, with efficient biogas exploitation, fulfilling renewable energy targets and green-house gases emission reduction, in particular in tropical countries, where limited reactor heating is required.

Anaerobic pre-treatment of petrochemical effluents: terephthalic acid wastewater

1997 ◽  
Vol 36 (2-3) ◽  
pp. 237-248 ◽  
Author(s):  
Robbert Kleerebezem ◽  
Joost Mortier ◽  
Look W. Hulshoff Pol ◽  
Gatze Lettinga
Keyword(s):  
Acetic Acid ◽  
Benzoic Acid ◽  
Terephthalic Acid ◽  
Anaerobic Degradation ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Pre Treatment ◽  
Uasb Reactors

During petrochemical production of purified terephthalic acid (PTA, 1,4-benzene dicarboxylic acid), a large quantity of concentrated effluent is produced. Main polluting compounds in this wastewater are terephthalic acid, acetic acid and benzoic acid in decreasing order of concentration. Acetic acid and benzoic acid are known to be rapidly degraded in high rate anaerobic treatment systems, such as Upflow Anaerobic Sludge Bed (UASB) reactors. Concerning the kinetics of anaerobic mineralization of terephthalic acid, however, no information is available in literuature. Therefore our work focused on the anaerobic degradation of neutralized terephthalic acid (disodium terephthalate) in laboratory scale UASB-reactors and batch reactors. It was found that high rate anaerobic treatment of terephthalate was difficult to obtain due to the low growth rate (μ ≈ 0.04 day−1) of the terephthalate mineralizing mixed culture. The maximum removal capacity of a lab-scale UASB-reactor was found to be 3.9 g COD.1−1 .day−1 at a loading rate of 4.5 g COD.1−1 .day−1 and a hydraulic retention time of 24 hours. Terephthalate was used as sole carbon source during these experiments. Addition of small amounts of sucrose (co-substrate) to the influent, as a source of reducing equivalents, was found to have a negative influence on the anaerobic degradation of terephthalate. Also benzoate was found to inhibit the mineralization of terephthalate. Batch-toxicity experiments showed that terephthalate is not toxic to any of the species involved in its mineralization. Based on these observations, a staged anaerobic reactor system is suggested for the anaerobic pre-treatment of PTA-wastewater.

Advanced Reactor Design, Operation and Economy

1986 ◽  
Vol 18 (12) ◽  
pp. 99-108 ◽  
Author(s):  
Gatze Lettinga ◽  
Look Hulshoff Pol
Keyword(s):  
Suspended Solids ◽  
Granular Sludge ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Internal Circulation ◽  
Inlet System ◽  
Anaerobic Sludge Blanket ◽  
Feed Inlet

Of the high rate anaerobic wastewater treatment systems the UASB (Upflow Anaerobic Sludge Blanket) reactor has found the widest application. Therefore the attention with respect to design, operation and economy will be focussed on this reactor type. In designing a UASB reactor specific attention is needed for the GSS (Gas-Solids Separator) device and the feed inlet system. For soluble wastewater generally no phase separation is required. Only for wastewaters high in suspended solids pre-acidification in a separate acidification reactor can be beneficial. Increasing attention is given to the development of modified UASB systems, such as a combination of a sludge bed reactor and an anaerobic filter. Other possible modified UASB systems may be found in a FS (Floating Settling) UASB reactor, the EGSB (Expanded Granular Sludge Bed) reactor and the UASB IC (Internal Circulation) reactor. As many factors are involved in the costs of a UASB reactor, only some rough data on reactor costs are presented.

Design Operation and Economy of Anaerobic Treatment

1983 ◽  
Vol 15 (8-9) ◽  
pp. 177-195 ◽  
Author(s):  
G Lettinga ◽  
S W Hobma ◽  
L W Hulshoff Pol ◽  
W de Zeeuw ◽  
P de Jong ◽  
...  
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Waste Water Treatment ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Water Treatment Process ◽  
Filter Process ◽  
Anaerobic Sludge Blanket

This paper aims to contribute to the assesment of a (more) optimal design and operation of a high rate anaerobic waste water treatment process. The discussion will be made on basis of available information of modern anaerobic waste water treatment processes, such as the Anaerobic Filter Process and the Upflow Anaerobic Sludge Blanket process and of recently introduced Attached Film processes.

Anaerobic treatment of Wastewater from a fish-canning factory in a full-scale Upflow Anaerobic Sludge Blanket (UASB) reactor

1999 ◽  
Vol 40 (8) ◽  
pp. 57-62 ◽  
Author(s):  
A. Pun˜al ◽  
J. M. Lema
Keyword(s):  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Total Alkalinity ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Stable Operation ◽  
Start Up ◽  
Upward Velocity ◽  
Anaerobic Sludge Blanket

The start-up and optimisation of a 380 m3 UASB reactor (Up-flow Anaerobic Sludge Blanket) treating wastewater from a fish-canning factory was carried out. At the beginning of the operation the Organic Loading Rate (OLR) was 1 kg COD/m3·d. Then, the load was gradually increased in steps of 50% OLR until the final capacity of the system (4 kg COD/m3·d) was achieved. Wastewater characteristics were highly dependent on the canned product (mussel, tuna, sardines, etc.). In spite of that, a stable operation working at a hydraulic retention time (HRT) of 2 days was maintained. Total Alkalinity (TA) always presented values higher than 3 g CaCO3/l, while the IA/TA ratio (Intermediate Alalinity/Total Alkalinity) was always maintained lower than 0.3. In order to improve granulation conditions, upward velocities from 0.5 to 0.8 m/h were applied. The highest values caused the washout of non-granulated biomass from the reactor, optimum operation being achieved at an upward velocity of 0.7 m/h.

Effective carbon and nutrient treatment solutions for mixed domestic-industrial wastewater in India

2015 ◽  
Vol 72 (4) ◽  
pp. 651-657 ◽  
Author(s):  
S. Saha ◽  
N. Badhe ◽  
D. Seuntjens ◽  
S. E. Vlaeminck ◽  
R. Biswas ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Urban Areas ◽  
Treatment Options ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Fecal Coliforms ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Sludge Blanket

The present study evaluates effectiveness of up-flow anaerobic sludge blanket (UASB) reactor followed by two post-anaerobic treatment options, namely free-surface, up-flow constructed wetland (FUP-CW) and oxygen-limited anaerobic nitrification/denitrification (OLAND) processes in treating sewage from the peri-urban areas in India receiving illegal industrial infiltrations. The UASB studies yielded robust results towards fluctuating strength of sewage and consistently removed 87–98% chemical oxygen demand (COD) at a hydraulic retention time of 1.5–2 d. The FUP-CW removed 68.5 ± 13% COD, 68 ± 3% NH4+-N, 38 ± 5% PO43−-P, 97.6 ± 5% suspended particles and 97 ± 13% fecal coliforms. Nutrient removal was found to be limiting in FUP-CW, especially in winter. Nitrogen removal in the OLAND process were 100 times higher than the FUP-CW process. Results show that UASB followed by FUP-CW can be an excellent, decentralized sewage treatment option, except during winter when nutrient removal is limited in FUP-CW. Hence, the study proposes bio-augmentation of FUP-CW with OLAND biomass for overall improvement in the performance of UASB followed by FUP-CW process.

High-Rate Anaerobic Treatment of Industrial Wastewaters

1991 ◽  
Vol 24 (1) ◽  
pp. 69-74 ◽  
Author(s):  
J. Rintala
Keyword(s):  
Granular Sludge ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Industrial Wastewaters ◽  
Start Up ◽  
Uasb Reactors

Anaerobic mesophilic treatment of synthetic (a mixture of acetate and methanol) and thermomechanical pulping (TMP) wastewater was studied in laboratory-scale upflow anaerobic sludge blanket (UASB) reactors and filters with emphasis on the process start-up. The reactors were inoculated with nongranular sludge. The start-up of mesophilic and thermophilic processes inoculated with mesophilic granular sludge was investigated in UASB reactors fed with diluted vinasse. The start-up proceeded faster in the filters than in the UASB reactors with TMP and synthetic wastewater. Loading rates of over 15 kgCODm−3d−1 with 50-60 % COD removal efficiencies were achieved in 10 days in the mesophilic and in 50 days in the thermophilic UASB reactor treating vinasse. The results show that high-rate anaerobic treatment can be applied to different types of industrial wastewaters under varying conditions.

Bicarbonate dosing: a tool to performance recovery of a thermophilic methanol-fed UASB reactor

2003 ◽  
Vol 48 (6) ◽  
pp. 95-101 ◽  
Author(s):  
P.L. Paulo ◽  
J.B. van Lier ◽  
G. Lettinga
Keyword(s):  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Recovery Strategy ◽  
Batch Mode ◽  
Performance Recovery ◽  
Complete Failure ◽  
Ph Shock ◽  
Anaerobic Sludge Blanket

The thermophilic-anaerobic treatment of methanol-containing wastewater in an upflow anaerobic sludge blanket (UASB) reactor, was found to be quite sensitive to pH shocks, both acid and alkaline. The results of the recovery experiments of sludge exposed to an alkaline shock, indicated that the addition or deprivation of sodium bicarbonate (NaHCO3) in the medium, plays an important role in the competition of methanogens and (homo)acetogens for methanol. In addition, caution has to be taken when using NaHCO3 for buffering methanol-containing wastewaters, since its introduction in the system will favour (homo)acetogenesis when proper conditions are not established. Based on these results, a recovery strategy for methanogenesis was proposed where bicarbonate is supplied stepwise, and the reactor is operated in a batch mode. This strategy was found to be appropriate, i.e. the results revealed that the recovery of methanogenesis on methanol from a reactor upset or complete failure caused by pH shock is possible, even in systems where (homo)acetogens are outcompeting methanogens. The time and the number of feedings required will depend on the degree of deterioration of the sludge.

Comparing the performance of UASB and GRABBR treating low strength wastewaters

2008 ◽  
Vol 58 (1) ◽  
pp. 225-232 ◽  
Author(s):  
A. S. Shanmugam ◽  
J. C. Akunna
Keyword(s):  
High Strength ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Low Strength ◽  
Equal Capacity ◽  
Anaerobic Sludge Blanket ◽  
The Comparative Study

Anaerobic technologies have proved successful in the treatment of various high strength wastewaters with perceptible advantages over aerobic systems. The applicability of anaerobic processes to treat low strength wastewaters has been increasing with the evolution of high-rate reactors capable of achieving high sludge retention time (SRT) when operating at low HRT. However, the performance of these systems can be affected by high variations in flow and wastewater composition. This paper reports on the comparative study carried out with two such high rate reactors systems to evaluate their performances when used for the treatment of low strength wastewaters at high hydraulic rates. One of the two systems is the most commonly used upflow anaerobic sludge blanket (UASB) reactor in which all reactions occur within a single vessel. The other is the granular bed baffled reactor (GRABBR) that encourages different stages of anaerobic digestion in separate vessels longitudinally across the reactor. The reactors, with equal capacity of 10 litres, were subjected to increasing organic loading rates (OLRs) and hydraulic retention times (HRTs) of up to 60 kg COD m−3 d−1 and 1 h respectively. Results show that the GRABBR has greater processes stability at relatively low HRTs, whilst the UASB seems to be better equipped to cope with organic overloads or shockloads. The study also shows that the GRABBR enables the harvesting of biogas with greater energetic value and hence greater re-use potential than the UASB. Biogas of up to 86% methane content is obtainable with GRABBR treating low strength wastewaters.

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