===Acknowledgements===
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'''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]]).'''
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An Anaerobic Biogas Reactor is a chamber or vault that facilitates the anaerobic degradation of blackwater, sludge, and/or biodegradable waste. It also facilitates the separation and collection of the biogas that is produced. The tanks can be built above or below ground. Prefabricated tanks or brick-constructed chambers can be built depending on space, resources and the volume of waste generated.
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 an alternative to a conventional septic tank, since it offers a similar level of treatment, but with the added benefit of biogas. Depending on the design and the inputs, the reactor should be emptied once every 6 months to 10 years.
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{{procontable | pro=
- Generation of a renewable, valuable energy source. <br> - Low capital costs; low operating costs. <br> - Underground construction minimizes land use. <br> - Long life span. <br> - Can be built and repaired with locally available materials. <br> - No electrical energy required. <br> - Small land area required (most of the structure can be built underground). | con=
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===Adequacy===
This technology is easily adaptable and can be applied at the household level or a small neighbourhood (refer to Technology Information Sheet T15: Anaerobic Biogas Reactor for information about applying it at the community level).
Depending on the soil, location, and size required, the reactor can be built above or below ground (even below roads). For more urban applications, small biogas reactors can be installed on the rooftops or in a courtyard. To minimize distribution losses, the reactors should be installed close to where the gas can be used. Biogas reactors are less appropriate for colder climates as gas production is not economically feasible below 15°C.
===Health Aspects/Acceptance===
The digested slurry is not completely sanitized 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.
Gas equipment should be cleaned carefully and regularly so that corrosion and leaks are prevented. Grit and sand that has settled to the bottom should be removed once every year. Capital costs for gas transmission infrastructure can increase the project cost. Depending on the quality of the output, the gas transmission capital costs can be offset by long-term energy savings.
==Acknowledgements=={{:Acknowledgements Sanitation}} ==References and external links===
* Food and Agriculture Organization (FAO) (1996). Biogas Technology: A Training Manual for Extension. Consolidated Management Services, Kathmandu. Available: http://www.fao.org
* Sasse, L. (1998). DEWATS: Decentralised Wastewater Treatment in Developing Countries. BORDA, Bremen Overseas Research and Development Association, Bremen, Germany.
===Acknowledgements===
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