<!{|style="float: left;"|{{Language-- table at top of page with logo, picture, Application level, Management level, and input-output tables -->box|english_link=Upflow_Anaerobic_Sludge_Blanket_Reactor|french_link=Digesteur_anaérobie_à_flux_ascendant|spanish_link=Reactor_Anaerobico_de_Flujo_Ascendente_con_Manto_de_Lodos|hindi_link=coming soon|malayalam_link=coming soon|tamil_link=coming soon | korean_link=coming soon | chinese_link=Coming soon | indonesian_link=Coming soon | japanese_link=Coming soon}}|}{|width="100%"|style="width:50%;"|{{santablesantable_new|
sys1=[[Single Pit System |1]]|
sys2=[[Blackwater Treatment System with Infiltration|56]]|sys3=[[Blackwater Treatment System with SewerageEffluent Transport|67]]|sys4=[[Blackwater Transport to (Semi-) Centralized Treatment System |78]]|sys5=[[Sewerage System with Urine Diversion |89]]|
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sys9=|
pic=Upflow_anaerobic_sludge_blanket_reactor1.png|
ApplHousehold=|
ManShared=|
ManPublic=XX|
Input1=Blackwater|Input2=Greywater |Input3= Brownwater | Input4= |Input5=|Output1= Effluent | Output2= Treated Sludge | Output3= Biogas | Output4= | Output5=
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|[[Image:Upflow_anaerobic_sludge_blanket_reactor1.png |right|500px]]
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[[Image:Icon_upflow_anaerobic_sludge_blanket_reactor.png |right|95px80px]]'''The Upflow Anaerobic Sludge Blanket Reactor (UASB) is a single tank process. Wastewater enters the reactor from the bottom, and flows upward. A suspended sludge blanket filters and treats the wastewater as the wastewater flows through it.'''
'''The upflow anaerobic sludge blanket reactor (UASB) is comprised of microbial granules, i.e. small agglomerations (0a single tank process.5 to 2mm in diameter) of microorganisms that, because of their weight, resist being washed out in Wastewater enters the upflow. The microorganisms in reactor from the sludge layer degrade organic compounds. As a resultbottom, gases (methane and carbon dioxide) are releasedflows upward. The rising bubbles mix the A suspendedsludge without the assistance of any mechanical parts. Sloped walls deflect material that reaches the top of blanket filters and treats the tank downwards. The clarified effluent is extracted from the top of the tank in an area above wastewater as the sloped wallswastewater flows through it.'''
After several weeks <br>The sludge blanket is comprised of microbial granules (1 to 3 mm in diameter), i.e., small agglomerations of usemicroorganisms that, larger granules because of their weight, resist being washed out in the upflow. The microorganisms in the sludge form which in turn act as filters for smaller particles as layer degrade organic compounds. As a result, gases (methane and carbon dioxide) are released. The rising bubbles mix the effluent rises through sludge without the cushion assistance of sludgeany mechanical parts. Because Sloped walls deflect material that reaches the top of the upflow regime, granule-forming organisms are preferentially accumulated as tank downwards. The clarified effluent is extracted from the top of the tank in an area above the others are washed outsloped walls.
The gas that After several weeks of use, larger granules of sludge form which, in turn, act as filters for smaller particles as the effluent rises to through the top is collected in a gas collection dome and can be used as energy (biogas)cushion of sludge. An Because of the upflow velocity of 0.6 to 0.9m/h must be maintained to keep regime, granule-forming organisms are preferentially accumulated as the sludge blanket in suspensionothers are washed out.
===Design Considerations===
Critical elements for the design of UASB reactors are the influent distribution system, the gas-solids separator, and the effluent withdrawal design. The gas that rises to the top is collected in a gas collection dome and can be used as energy (biogas). An upflow velocity of 0.7 to 1 m/h must be maintained to keep the sludge blanket in suspension. Primary settling is usually not required before the UASB.
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{{procontable | pro=
- High reduction in organics. <br> - Can withstand high organic loading rates (up to 10kg BOD/m3/d) and high hydraulic loading rates. <br> - Low production sludge (and thus, infrequent desludging required). <br> - Biogas can be used for energy (but usually requires scrubbing first). | con=
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===Appropriateness===
A UASB is not appropriate for small or rural communities without a constant water supply or electricity. The technology is relatively simple to design and build, but developing the granulated sludge may take several months. The UASB reactor has the potential to produce higher quality effluent than [[Septic Tank|Septic Tanks]] (S.9), and can do so in a smaller reactor volume. Although it is a well-established process for large-scale industrial wastewater treatment and high organic loading rates up to 10 kg BOD/m3/d, its application to domestic sewage is still relatively new.
==Adequacy==It is often used for brewery, distillery, food processing and pulp and paper waste since the process typically removes 80 to 90% of COD. Where the influent is low strength or where it contains too many solids, proteins or fats, the reactor may not work properly. Temperature is also a key factor affecting the performance. or fats, the reactor may not work properly. Temperature is also a key factor affecting the performance.
A UASB is not appropriate for small or rural communities without a constant water supply or electricity. A skilled operator is required to monitor ===Health Aspects/Acceptance=== The operators should take proper health and repair safety measures while working in the reactor plant, such as adequate protective clothing. Effluent and the pump in case of problems. Although the technology is simple to design sludge still pose a health risk and build, it is should not well proven for domestic wastewater, although new research is promisingbe directly handled.
===Operation & Maintenance=== The UASB reactor has the potential to produce higher quality effluent than Septic Tank|septic tanks]], is a Centralized Treatment technology that must be operated and can do so in a smaller reactor volumemaintained by professionals. Although it A skilled operator is a wellestablished process for large-scale industrial wastewater treatment processesrequired to monitor the reactor and repair parts, its application to domestic sewage is still relatively newe.g. Typically it is used for brewery, distillerypumps, food processing and pulp and paper waste since the process can typically remove 85% to 90% in case of Chemical Oxygen Demand (COD)problems. Where the influent Desludging is infrequent and only excess sludge is low strength, the reactor may not work properly. Temperature will also affect performanceremoved every 2 to 3 years.
==Health Aspects/Acceptance=References===* Lettinga, G., Roersma, R. and Grin, P. (1983). Anaerobic Treatment of Raw Domestic Sewage at Ambient Temperatures Using a Granular Bed UASB Reactor. Biotechnology and Bioengineering 25 (7): 1701-1723. (The first paper describing the process)
UASB is a centralized treatment technology that must be operated * von Sperling, M. and maintained by professionalsde Lemos Chernicharo, C. A. (2005). [https://www.iwapublishing.com/sites/default/files/ebooks/9781780402734.pdf Biological Wastewater Treatment in Warm Climate Regions, Volume One]. As with all wastewater processesIWA Publishing, London, operators should take proper health and safety measures while working in the plantUK. pp. 741-804.(Detailed design information)
==Maintenance==* Tare, V. and Nema, A. (n.d.). [http://unapcaem.org/Activities%20Files/A01/UASB%20Technology%20%E2%80%93%20Expectations%20and%20Reality.pdf UASB Technology – Expectations and Reality]. United Nations Asian and Pacific Centre for Agricultural Engineering and Machinery, Beijing, CN. (Assessment of UASB installations in India)
Desludging is infrequent * Tchobanoglous, G., Burton, F. L. and only excess sludge is removed once every 2 to 3 yearsStensel, H. D. A permanent operator is required to control (2004). Wastewater Engineering: Treatment and monitor the dosing pumpReuse, Metcalf & Eddy, 4th Ed. (Internat. Ed.). McGraw-Hill, New York, US. pp.1005-1016. (Book; Detailed description and design information)
* Ulrich, A. (Ed.), Reuter, S. (Ed.), Gutterer, B. (Ed.), Sasse, L., Panzerbieter, T. and Reckerzügel, T. (2009). [https://wedc-knowledge.lboro.ac.uk/resources/books/DEWATS_-_Chapter_01.pdf Decentralised Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries. A Practical Guide]. WEDC, Loughborough University, Leicestershire, UK. (Short overview)
==References==* Vigneswaran, S., Balasuriya, B. L. N. and Viraraghavan, T. (1986). [https://www.ircwash.org/sites/default/files/341.2-86AN-2504.pdf Environmental Sanitation Reviews. Anaerobic Wastewater Treatment – Attached Growth and Sludge Blanket Process]. Environmental Sanitation Information Center, AIT, Bangkok, TH. (Good technical overview – Chapter 5)
* Elizabeth Tilley et.al (2008). [http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_sesp/downloads_sesp/compendium_high.pdf Compendium of Sanitation Systems and Technologies] ([http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_sesp/downloads_sesp/compendium_low.pdf low res version]). Department of Water and Sanitation in Development Countries ([http://www.sandec.ch/ Sandec]) at the Swiss Federal Institute of Aquatic Science and Technology (Eawag). (Provides a full overview of sanitation systems.)===Acknowledgements=== * Crites, R. and Tchobanoglous, G. (1998). Small and decentralized wastewater management systems. WCB and McGraw-Hill, New York, USA. (Short overview.) * Lettinga, G., Roersma, R. and Grin, P. (1983). Anaerobic Treatment of Raw Domestic Sewage at Ambient Temperatures Using a Granular Bed UASB Reactor Biotechnology and Bioengineering 25 (7): 1701–1723. (The first paper describing the process.) * Sasse, L. (1998). DEWATS: Decentralised Wastewater Treatment in Developing Countries. BORDA, Bremen Overseas Research and Development Association, Bremen, Germany. (Short overview.) * von Sperlin, M. and de Lemos Chernicharo, CA. (2005). Biological Wastewater Treatment in Warm Climate Regions. Volume One. IWA, London, pp 741–804. (Detailed design information) * Tare, V. and Nema, A. (n.d). UASB Technology-expectations and reality. United Nations Asian and Pacific Centre for Agricultural Engineering and Machinery. Available: http://unapcaem.org (Assessment of UASB installations in India.) * Vigneswaran, S., et al. (1986). Environmental Sanitation Reviews{{: Anaerobic Wastewater Treatment- Attached growth and sludge blanket process. Environmental Acknowledgements Sanitation Information Center, AIT, Bangkok, Thailand. (Chapter 5 provides a good technical overview.)}}