Akvopedia-spade, akvouser, bot, bureaucrat, emailconfirmed, smwadministrator, smwcurator, susana-working-group-susana-member, administrator, widget editor
697
edits
Changes
→References
{|width="100%"
|style="width:50%;"|{{santable_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]]|
sys6=|
sys7=|
sys8=|
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=|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
}}
|[[Image:Upflow_anaerobic_sludge_blanket_reactor1.png |right|300px500px]]
|}
<br>
----
<br>
<br>The sludge blanket is comprised of microbial granules(1 to 3 mm in diameter), i.e. , small agglomerations (0.5 to 2mm in diameter) of microorganisms that, because of their weight, resist being washed out in the upflow. The microorganisms in the sludge layer degrade organic compounds. As a result, gases (methane and carbon dioxide) are released. The rising bubbles mix the sludge without the assistance of any mechanical parts. Sloped walls deflect material that reaches the top of the tank downwards. The clarified effluent is extracted from the top of the tank in an area above the sloped walls.
After several weeks of use, larger granules of sludge form which , in turn , act as filters for smaller particles as the effluent rises through the cushion of sludge. Because of the upflow regime, granule-forming organisms are preferentially accumulated as the others 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 0.6 7 to 0.9m1 m/h must be maintained to keep the sludge blanket in suspension. Primary settling is usually not required before the UASB.
<br>
{{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=
}}
==Adequacy=Appropriateness=== A UASB is not appropriate for small or rural communities without a constant water supply or electricity. A skilled operator is required to monitor and repair the reactor and the pump in case of problems. Although the The technology is relatively simple to design and build, it is not well proven for domestic wastewater, although new research is promisingbut developing the granulated sludge may take several months. The UASB reactor has the potential to produce higher quality effluent than [[Septic Tank|septic tanksSeptic Tanks]](S.9), and can do so in a smaller reactor volume. Although it is a wellestablished well-established process for large-scale industrial wastewater treatment processesand high organic loading rates up to 10 kg BOD/m3/d, its application to domestic sewage is still relatively new. Typically it is used for brewery, distillery, food processing and pulp and paper waste since the process can typically remove 85% to 90% of Chemical Oxygen Demand (COD). Where the influent is low strength, the reactor may not work properly. Temperature will also affect performance. ==Health Aspects/Acceptance== UASB is a centralized treatment technology that must be operated and maintained by professionals. As with all wastewater processes, operators should take proper health and safety measures while working in the plant.
==References=Operation & Maintenance=== The UASB is a Centralized Treatment technology that must be operated and maintained by professionals. A skilled operator is required to monitor the reactor and repair parts, e.g., pumps, in case of problems. Desludging is infrequent and only excess sludge is removed every 2 to 3 years.
===References===* CritesLettinga, G., Roersma, R. and TchobanoglousGrin, GP. (19981983). [http://books.googleAnaerobic Treatment of Raw Domestic Sewage at Ambient Temperatures Using a Granular Bed UASB Reactor.com/books/about/Small_and_decentralized_wastewater_manag.html?id=yx9SAAAAMAAJ Small Biotechnology and decentralized wastewater management systems]. WCB and McGrawBioengineering 25 (7): 1701-Hill, New York, USA1723.(The first paper describing the process)
* Lettingavon Sperling, GM.and de Lemos Chernicharo, Roersma, RC. and Grin, PA. (19832005). [httphttps://onlinelibrarywww.wileyiwapublishing.com/doisites/10.1002default/files/ebooks/bit9781780402734.260250703/abstract Anaerobic pdf Biological Wastewater Treatment of Raw Domestic Sewage at Ambient Temperatures Using a Granular Bed UASB Reactorin Warm Climate Regions, Volume One]. Biotechnology and Bioengineering 25 IWA Publishing, London, UK. pp. 741-804. (7Detailed design information): 1701–1723. The first paper describing the process.
* SasseTare, LV. and Nema, A. (1998n.d.). [http://www.indiawaterportalunapcaem.org/sites/indiawaterportal.orgActivities%20Files/filesA01/Decentralised_UASB%20wastewater_20Technology%20treatment_20%20in_E2%20developing_80%20countries_A_93%20handbook_20Expectations%20by_20and%20BORDA_199820Reality.pdf DEWATS: Decentralised Wastewater Treatment in Developing CountriesUASB Technology – Expectations and Reality]. BORDA, Bremen Overseas Research United Nations Asian and Pacific Centre for Agricultural Engineering and Development AssociationMachinery, BremenBeijing, GermanyCN. (Assessment of UASB installations in India)
* von SperlinTchobanoglous, MG., Burton, F. L. and de Lemos ChernicharoStensel, CAH. D. (20052004). [httpWastewater Engineering://wwwTreatment and Reuse, Metcalf & Eddy, 4th Ed.iwapublishing(Internat.com/pdf/contents/isbn1843390027_contentsEd.pdf Biological Wastewater Treatment in Warm Climate Regions]). Volume One. IWAMcGraw-Hill, LondonNew York, US. pp 741–804. 1005-1016. (Book; Detailed description and design information.)
* TareUlrich, VA. (Ed.), Reuter, S. (Ed.), Gutterer, B. (Ed.), Sasse, L., Panzerbieter, T. and NemaReckerzügel, AT. (n.d2009). [httphttps://unapcaemwedc-knowledge.lboro.ac.orguk/Activities%20Filesresources/A01books/UASB%20Technology%20%E2%80%93%20Expectations%20and%20RealityDEWATS_-_Chapter_01.pdf UASB Technology-expectations Decentralised Wastewater Treatment Systems (DEWATS) and reality]Sanitation in Developing Countries. [http://unapcaem.org United Nations Asian and Pacific Centre for Agricultural Engineering and MachineryA Practical Guide]. Assessment of UASB installations in IndiaWEDC, Loughborough University, Leicestershire, UK.(Short overview)
* Vigneswaran, S., et alBalasuriya, B. L. N. and Viraraghavan, T. (1986). [httphttps://bookswww.googleircwash.comorg/bookssites/aboutdefault/Anaerobic_Wastewater_Treatmentfiles/341.2-86AN-2504.html?id=NIJJcgAACAAJ pdf Environmental Sanitation Reviews: . Anaerobic Wastewater Treatment- – Attached growth Growth and sludge blanket processSludge Blanket Process]. Environmental Sanitation Information Center, AIT, Bangkok, ThailandTH. (Good technical overview – Chapter 5 provides a good technical overview.)
===Acknowledgements===
{{:Acknowledgements Sanitation}}