<!{|style="float: left;"|{{Language-- table at top of page with logo, picture, Application level, Management level, and input-output tables -->box|english_link=Biogas_Reactor|french_link=Réacteur_anaérobie_à_Biogaz|spanish_link=Reactor_Anaerobico_de_Biogas|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 }}|}
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|style="width:50%;"|{{santable_new|sys1=[[Pour Flush Single Pit System with Twin Pits|31]]|sys2=[[Blackwater Treatment System with SewerageInfiltration|6]]|sys3=[[Blackwater Treatment System with Effluent Transport|7]]|sys4=[[Blackwater Transport to (Semi-) Centralized Treatment System|8]]|sys5=[[Sewerage System with Urine Diversion|9]]|
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pic=Anaerobic_biogas_reactor.png|
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Input1=Faecal Sludge|Input2=Organics |Input3=Blackwater| Input4= Brownwater |Input5=|Output1=Treated Sludge|Output2=Effluent Biogas | Output3=Biogas | Output4= | Output5=|english_link=Anaerobic_Biogas_Reactor|french_link=Réacteur_anaérobie_à_Biogaz|spanish_link=Reactor_Anaerobico_de_Biogas
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[[Image:Icon_anaerobic_biogas_reactor.png |right|95px]]<br>'''An Anaerobic Biogas Reactor is an anaerobic treatment technology that produces (a) a digested slurry to be used as a soil amendment and (b) biogas which can be used for energy. Biogas is a mix of methane, carbon dioxide and other trace gasses that can be easily converted to electricity, light and heat (see [[Biogas as source of energy]]).'''----<br>
An Anaerobic Biogas Reactor [[Image:Icon_anaerobic_biogas_reactor.png |right|80px]]'''A biogas reactor or anaerobic digester is an anaerobic treatment technology that produces (a) a chamber or vault digested slurry (digestate) that facilitates the anaerobic degradation of blackwater, sludge, can be used as a fertilizer and/or biodegradable waste. It also facilitates the separation and collection of the (b) biogas that is produced. The tanks can be built above or below groundused for energy. Prefabricated tanks or brick-constructed chambers Biogas is a mix of methane, carbon dioxide and other trace gases which can be built depending on spaceconverted to heat, resources and the volume of waste generatedelectricity or light.'''
[[Image:Anaerobic_digestion.PNG|thumb|right|150px200px|Biogas reactor in Vietnam (for credits, click the picture)]]
The residence time A biogas reactor is an airtight chamber that facilitates the anaerobic degradation of blackwater, sludge, and/ or biodegradable waste. It also facilitates the collection of the fluid biogas produced in the fermentation processes in the reactor should a minimum of 15 days . The gas forms in hot climates the slurry and 25 days in temperate climates. For highly pathogenic inputs, a residence time collects at the top of 60 days should be considered. Normallythe chamber, Anaerobic Biogas Reactors are not heated, but to ensure pathogen destruction (imixing the slurry as it rises.e. a sustained temperature over 50°C) the reactor should be heated (although The digestate is rich in practiceorganics and nutrients, this is only found in the most industrialized countries)almost odourless and pathogens are partly inactivated.
Once waste products enter the digestion chamber===Design Considerations=== Biogas reactors can be brick-constructed domes or prefabricated tanks, installed above or below ground, depending on space, soil characteristics, gases are formed through fermentation. The gas forms in available resources and the sludge but collects at the top volume of the reactor, mixing the slurry as it riseswaste generated. Biogas reactors They can be built as fixed dome or floating dome reactorsdigesters. In the fixed dome reactor , the volume of the reactor is constant. As gas is generated it exerts a pressure and displaces the slurry upward into an expansion chamber. When the gas is removed, the slurry will flow flows back down into the digestion chamberreactor. The pressure generated can be used to transport the biogas through pipes. In a floating dome reactor, the dome rises and falls with the production and withdrawal of gas. Alternatively, it canexpand (like a balloon). To minimize distribution losses, the reactors should be installed close to where the gas can be used.
In a floating dome The hydraulic retention time (HRT) in the reactor, the dome will rise and fall with the production should be at least 15 days in hot climates and withdrawal of gas25 days in temperate climates. AlternativelyFor highly pathogenic inputs, the dome can expand (like a balloon)HRT of 60 days should be considered. Most often Normally, biogas reactors are directly connected operated in the mesophilic temperature range of 30 to indoor (private or public) toilets with an additional access point for organic materials38 °C. At A thermophilic temperature of 50 to 57 °C would ensure the household levelpathogens destruction, reactors can be made out of plastic containers or bricks and but can only be built behind achieved by heating the house or buried underground. Sizes can vary from 1reactor (although in practice,000L for a single family up to 100,000L for institutional or public toilet applicationsthis is only found in industrialized countries).
The slurry that is produced is rich in organics and nutrients, but almost odourless and partly disinfected (complete pathogen destruction would require thermophilic conditions). Often, a biogas reactor is used as reactors are directly connected to private or public toilets with an alternative to a conventional septic tankadditional access point for organic materials. At the household level, reactors can be made out of plastic containers or bricks. Sizes can vary from 1, since it offers 000 L for a similar level of treatmentsingle family up to 100, but with the added benefit of biogas000 L for institutional or public toilet applications. Depending on Because the design digestate production is continuous, there must be provisions made for its storage, use and /or transport away from the inputs, the reactor should be emptied once every 6 months to 10 yearssite.
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{{procontable | pro=
- Generation of a renewable, valuable energy source. <br> - Low capital costs; low operating costs. <br> - Underground construction minimizes Small land use. area required (most of the structure can be built underground) <br> - Long life span. No electrical energy required <br> - Can be built and repaired with locally available materials. Conservation of nutrients <br> - No electrical energy required. Long service life <br> - Small land area required (most of the structure can be built underground). Low operating costs| con=- Requires constant source of water. <br> - Requires expert design and skilled construction. <br> - Gas production below 15°C is not economically feasible. Incomplete pathogen removal, the digestate might require further treatment <br> - Digested sludge and effluent still requires treatment Limited gas production below 15 °C
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==Adequacy=Appropriateness=== This technology is easily adaptable and can be applied at the household level , in small neighbourhoods or for the stabilization of sludge at large wastewater treatment plants. It is best used where regular feeding is possible. Often, a small neighbourhood biogas reactor is used as an alternative to a [[Septic Tank | Septic Tank]] (refer S.9), since it offers a similar level of treatment, but with the added benefit of biogas. However, significant gas production cannot be achieved if blackwater is the only input. The highest levels of biogas production are obtained with concentrated substrates, which are rich in organic material, such as animal manure and organic market or household waste. It can be efficient to Technology Information Sheet T15: Anaerobic Biogas Reactor for information about applying it at co-digest blackwater from a single household with manure if the latter is the community level)main source of feedstock.
Greywater should not be added as it substantially reduces the HRT. Wood material and straw are difficult to degrade and should be avoided in the substrate. Biogas reactors are best used less appropriate for concentrated products (i.e. rich in colder climates as the rate of organic material)matter conversion into biogas isvery low below 15 °C. If they are installed for a single household that is using a significant amount of waterConsequently, the efficiency of the reactor can HRT needs to be improved significantly by also adding animal manure longer and biodegradable organic wastethe design volume substantially increased.
===Health Aspects/Acceptance=== The digestate is partially sanitized but still carries a risk of infection. Depending on the soilits end-use, location, and size further treatment might be required, . There are also dangers associated with the reactor can be built above or below ground (even below roads). For more urban applicationsflammable gases that, small biogas reactors can be installed on the rooftops or in a courtyard. To minimize distribution lossesif mismanaged, the reactors should could be installed close harmful to where the gas can be used. Biogas reactors are less appropriate for colder climates as gas production is not economically feasible below 15°Chuman health.
==Health Aspects/Acceptance=Operation & Maintenance=== If the reactor is properly designed and built, repairs should be minimal. To start the reactor, it should be inoculated with anaerobic bacteria, e.g., by adding cow dung or Septic Tank sludge. Organic waste used as substrate should be shredded and mixed with water or digestate prior to feeding. Gas equipment should be carefully and regularly cleaned so that corrosion and leaks are prevented. Gritand sand that have settled to the bottom should be removed. Depending on the design and the inputs, the reactor should be emptied once every 5 to 10 years.
The digested slurry is not completely sanitized ===References and still carries a risk of infection. There are also dangers associated with the flammable gases that, if mismanaged, could be harmful to human health.external links===
The Anaerobic Biogas Reactor must be well built and gas tight for safety* CMS (1996). If the reactor is properly designed, repairs should be minimal[http://www. To start the reactor, active sludge (efao.gorg/3/ae897e/ae897e00. from a septic tank) should be used as a seedhtm Biogas Technology: A Training Manual for Extension. The tank is essentially selfFAO/TCP/NEP/4451-mixingT]. Consolidated Management Services, Kathmandu, but it should be manually stirred once a week to prevent uneven reactionsNP.
Gas equipment should be cleaned carefully * GTZ (1998). Biogas Digest. [https://www.susana.org/en/knowledge-hub/resources-and regularly so that corrosion -publications/library/details/525?pgrid=1 Volume I], [https://www.susana.org/en/knowledge-hub/resources-and leaks are prevented-publications/library/details/526 Volume II], [https://www.susana. Grit org/en/knowledge-hub/resources-and sand that has settled to the bottom should be removed once every year-publications/library/details/1717 Volume III], [https://energypedia. Capital costs for gas transmission infrastructure can increase the project costinfo/images/1/17/Biogas_gate_volume_4. Depending pdf Volume IV]. Information and Advisory Service on the quality of the outputAppropriate Technology (ISAT). Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH, the gas transmission capital costs can be offset by long-term energy savingsEschborn, DE.
==Acknowledgements=={{* Mang, H.-P. and Li, Z. (2010). [https:Acknowledgements //www.susana.org/en/knowledge-hub/resources-and-publications/library/details/877 Technology Review of Biogas Sanitation}}. Draft – Biogas Sanitation for Blackwater, Brown Water, or for Excreta Treatment and Reuse in Developing Countries]. Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, DE.
==References * Ulrich, A. (Ed.), Reuter, S. (Ed.), Gutterer, B. (Ed.), Sasse, L., Panzerbieter, T. and external links==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.
* Food Vögeli, Y., Lohri, C. R., Gallardo, A., Diener, S. and Agriculture Organization Zurbrügg, C. (FAO) (19962014). Biogas Technology[https: A Training Manual for Extension//www. Consolidated Management Services, Kathmandueawag. Available: http:ch/fileadmin/Domain1/Abteilungen/sandec/publikationen/SWM/Anaerobic_Digestion/wwwbiowaste.pdf Anaerobic Digestion of Biowaste in Developing Countries. Practical Information and Case Studies].faoEawag (Department Sandec), Dübendorf, CH.org
* ISAT (1998). Biogas Digest Vols. I–IV. ISAT and GTZ, Germany. Available: http://www.gtz.de * Koottatep, S., Ompont, M. and Joo Hwa, T. (2004). Biogas: A GP Option For Community Development. Asian Productivity Organization, Japan. Available: http://www.apo-tokyo.org * Rose, GD. (1999). Community-Based Technologies for Domestic Wastewater Treatment and Reuse: options for urban agriculture. IDRC, Ottawa. pp 29–32. Available: http://idrinfo.idrc.ca===Acknowledgements===* Sasse, L. (1998). DEWATS{{: Decentralised Wastewater Treatment in Developing Countries. BORDA, Bremen Overseas Research and Development Association, Bremen, Germany.Acknowledgements Sanitation}}