Operation of UASB reactors for sewage treatment

2019 ◽  
pp. 126-158
Keyword(s):  
Sewage Treatment ◽  
Uasb Reactors

scholarly journals Constraints, performance and perspectives of anaerobic sewage treatment: lessons from full-scale sewage treatment plants in Brazil

2019 ◽  
Vol 80 (3) ◽  
pp. 418-425 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
L. A. Chamhum-Silva ◽  
C. A. L. Chernicharo
Keyword(s):  
Sewage Treatment ◽  
Full Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Operational Performance ◽  
Anaerobic Sludge ◽  
Anaerobic Reactors ◽  
Anaerobic Sludge Blanket ◽  
Operational Constraints ◽  
Uasb Reactors ◽  
Design Construction

Abstract There are hundreds of full-scale upflow anaerobic sludge blanket (UASB) reactors in operation in various parts of the tropical world, notably in India and Latin America, Brazil being the holder of the largest park of anaerobic reactors for sewage treatment in the world. Despite the recognized advantages of UASB reactors, there are problems that have prevented their maximum operational performance. Neglecting the existence and delaying the solution of these challenges can jeopardize the important advances made to date, impacting the future of anaerobic technology in Brazil and in other countries. This work aims to evaluate the operational performance of five full-scale UASB reactors in Brazil, taking into account a monitoring period ranging between two and six years. The main observed design, construction, and operational constraints are discussed. Some outlooks for important upcoming developments are also provided, considering that most of the observed drawbacks can be tackled without significant increases on reactor costs.

Anaerobic treatment of domestic sewage: established technologies and perspectives

2002 ◽  
Vol 45 (10) ◽  
pp. 181-186 ◽  
Author(s):  
E. Foresti
Keyword(s):  
Sewage Treatment ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Anaerobic Reactors ◽  
Resources Conservation ◽  
In The Beginning ◽  
Conventional Systems ◽  
Further Development ◽  
Uasb Reactors ◽  
Research Centres

The use of anaerobic reactors for domestic sewage treatment has increased significantly since the UASB configuration started to be efficiently applied for this purpose in the beginning of the 1980s. Nowadays, hundreds of UASB reactors, or similar anaerobic units, are used in domestic sewage treatment systems, particularly in developing countries. These units have been operated at ambient temperature, normally higher than 20°C, at hydraulic detention time in the range of 6 to 10 hours, and organic loading rates lower than 3.0 kg COD.m−3.d−1. They have presented COD removal efficiencies in the range of 65% to 80%. Besides, new configurations have been developed and assayed in research centres, aiming to amplify the range of application and to improve process performance. At the same time, research is being conducted on the post-treatment of anaerobic effluents attempting to offer alternatives to the existing conventional systems. It takes into consideration not only sanitation and environmental protection, but also considers resources conservation at lower construction and running costs as the main supporting concepts for further development. This text presents some aspects of the consolidated technologies and suggests on further developments in the conception of domestic sewage treatment systems having the anaerobic process as their core.

scholarly journals Influence of temperature on the performance of anaerobic treatment systems of municipal wastewater

Water SA ◽  
2018 ◽  
Vol 44 (2 April) ◽  
Author(s):  
Silvânia Lucas Dos Santos ◽  
Sílvia Raphaele Morais Chaves ◽  
Adrianus Van Haandel
Keyword(s):  
Experimental Investigation ◽  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Poor Performance ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Uasb Reactors

Anaerobic sewage treatment systems, especially upflow anaerobic sludge blanket (UASB) reactors, have found wide application over the past decades, particularly in regions with a warm climate. A low sewage temperature is generally considered as a factor contributing to poor performance, characterized by an increase of the COD fractions in the effluent and the generated sludge, and decreasing the fraction that is transformed into methane. An experimental investigation was carried out at pilot scale to establish the values of the three COD fractions for different values of temperature and the applied organic load. The sludge age of the anaerobic treatment, together with temperature, was identified as the main operational variable that affects the efficiency of anaerobic treatment. An empirical expression was derived for the values of the three factions as a function of these two variables. From the results of the experimental investigation it was apparent that there is no point in applying a sludge age of more than 100 d, when the reactor is near its best performance. An expression was derived to establish the hydraulic retention time for maximum digestion efficiency as a function of temperature, concentration and composition of organic material and sludge mass. It was established that the main limit to the sludge hold-up in UASB reactors treating sewage is not the sludge settleability, but rather the break-up of flocs leading to loss of small, poorly-settling particles.

Anaerobic Sewage Treatment using UASB Reactors: Engineering and Operational Aspects

2010 ◽  
pp. 59-89 ◽  
Author(s):  
Jules B. Van Lier ◽  
Anand Vashi ◽  
Jeroen Van Der Lubbe ◽  
Barry Heffernan
Keyword(s):  
Sewage Treatment ◽  
Uasb Reactors ◽  
Operational Aspects

Domestic sewage treatment in full-scale UASBB plant at Mangueira, Recife, Pernambuco

2001 ◽  
Vol 44 (4) ◽  
pp. 71-77 ◽  
Author(s):  
L. Florencio ◽  
M. Takayuki Kato ◽  
J. Cardoso de Morais
Keyword(s):  
Sewage Treatment ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Metropolitan Region ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Active Biomass ◽  
Methanogenic Activity ◽  
Technology Application ◽  
Uasb Reactors

The anaerobic technology application for domestic sewage treatment in Pernambuco State (Brazil) is relatively recent. Some UASB reactors of less than 250 m3 were built in the Recife Metropolitan Region (RMR) in the 1990s. Mangueira (18,000 inhabitants) was the first neighborhood where the municipality built a plant with a bigger UASB reactor of 810 m3. It was intended to evaluate the performance and verify if such technology would be feasible. The objective would be the possible application of UASB reactors to the RMR, according to the new sewage master-plan under elaboration that would benefit about 3 million inhabitants. The monitoring of the Mangueira UASB reactor over 30 months showed that satisfactory results were obtained. Three distinct operational phases occurred, in which efficiency varied from 60% up to 90% based on COD removal. The results were very dependent on the operation and maintenance, either in the plant or in the sewage collection. Significant amount of inert solids was measured inside the reactor. Despite the operational problems, the UASB was shown to be very robust and stable. Under high fluctuation of influent concentrations (150-750 mg COD/L) during the period, resulting in applied organic loading rate of 0.5 to 2.5 kg COD/m3.d, the average values of COD removal efficiency did not change significantly. An active biomass with specific methanogenic activity varying from 0.18 to 0.25 gCOD/gVSS.d was measured at the end of the period.

Full-Scale Application of the UASB Technology for Sewage Treatment

1992 ◽  
Vol 25 (7) ◽  
pp. 159-166 ◽  
Author(s):  
A. Schellinkhout ◽  
C. J. Collazos
Keyword(s):  
Large Scale ◽  
Sewage Treatment ◽  
Pilot Scale ◽  
Real Cost ◽  
Treatment Information ◽  
In Series ◽  
Per Capita ◽  
The Cost ◽  
Uasb Reactors ◽  
Design Construction

In recent years, many pilot-scale investigations were reported on the application of the UASB concept for sewage treatment. Information about large-scale experience is scarce, however. This paper describes the experience obtained with the design, construction and initial operation of a 160,000 PE (31,000 m3/day, 8 MGD) plant in Colombia, consisting of UASB reactors and a facultative pond in series. It describes the possibilities and limitations of the use of prefab concrete as a building material for UASB reactors. The real cost of erection of the plant was USD 17 per capita; the cost for operation and maintenance amounted to USD 1.50 per capita.

scholarly journals Energy potential of biogas and sludge from UASB reactors in the State of Paraná, Brazil

2020 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Lucas Sampaio Lopes ◽  
Andre Pereira Rosa ◽  
Júlia Silva Marco ◽  
Gustavo Rafael Collere Possetti ◽  
Tayane Cristiele Rodrigues Mesquita
Keyword(s):  
Sewage Treatment ◽  
The State ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Energy Potential ◽  
Total Potential ◽  
Recovery Potential ◽  
Gis Tools ◽  
Uasb Reactors ◽  
By Products

 Upflow Anaerobic Sludge Blanket (UASB) reactors are widely used for domestic sewage treatment in Brazil, and generate sludge and biogas as by-products. Typically, the sludge is sent to sanitary landfills, and the biogas is burned in flares. This study assessed the energy potential of these by-products in sewage treatment plants (STPs) located in the state of Paraná, Brazil. First, an overview of biogas energy recovery potential in a full-scale STP based on UASB reactors was carried out. Afterwards, a total of 239 STPs in the state of Paraná were assessed, and the energy potential of the by-products was estimated by a mathematical model. Data were spatially classified using ArcGIS®, taking into account the different effluent characteristics (worst, typical and best scenario), sludge dehydration systems (drying bed and centrifuge) and sizes (small, medium and large). Among the states in Brazil, Paraná presented the highest biogas potential, although nowadays it exploits only 0.4% of its capacity. Biogas was the main by-product generated by UASB reactors in Paraná, and if used in the entire state, it could supply the energy demands of a city with 111,000 inhabitants. Biogas corresponded to 65, 64 and 74% of the total potential (sludge and biogas) for small, medium and large STPs, respectively. The study of the energy potential of the by-products associated with GIS tools positively contributes to the decision-making process in sanitation management and to improve energy sustainability.

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