<!{|style="float: left;"|{{Language-- table at top of page with logo, picture, Application level, Management level, and input-output tables -->box|english_link=Anaerobic_Filter|french_link=Filtre_Anaérobie|spanish_link=Filtro_Anaerobico|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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sys1=[[Blackwater Treatment System with Infiltration|56]]|sys2=[[Blackwater Treatment System with SewerageEffluent Transport|67]]|
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ApplHousehold=XXX|
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ManHousehold=XXX|
ManShared=XX|
ManPublic=XX|
Input1=Blackwater|Input2=GreywaterBrownwater|Input3=Greywater| Input4= |Input5=|Output1=Faecal SludgeEffluent|Output2=Effluent Sludge | Output3= | Output4= | Output5=|english_link=Anaerobic_Filter|french_link=Filtre_Anaérobie|spanish_link=Filtro_Anaerobico
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<br>----<br> [[Image:Icon_anaerobic_filter.png |right|95px80px]]'''An Anaerobic Filter anaerobic filter is a fixed-bed biological reactorwith one or more filtration chambers in series. As wastewater flows through the filter, particles are trapped and organic matter is degraded by the active biomass that is attached to the surface of the filter material.''' <br>With this technology, suspended solids and BOD removal can be as high as 90%, but is typically between 50% and 80%. Nitrogen removal is limited and normally does not exceed 15% in terms of total nitrogen (TN).
This technology consists ===Design Considerations=== Pre- and primary treatment is essential to remove solids and garbage that may clog the filter. The majority of settleable solids are removed in a sedimentation tank chamber in front of the anaerobic filter. Small-scale, stand-alone units typically have an integrated settling compartment, but primary sedimentation can also take place in a separate [[Settler]] (T.1) or another preceding technology (e.g., existing [[Septic Tank]]s) followed by one or more filter chambers. Filter material commonly used includes gravel, crushed rocks, cinder, or specially formed plastic pieces. Typical filter material sizes range from 12 to 55mm Designs without a settling compartment (as shown in diameterT. Ideally, the material will provide between 90 to 300m2 of surface area per 1m3 4) are of reactor volume. By providing a large surface area particular interest for (Semi-) Centralized Treatment plants that combine the bacterial massanaerobic filter with other technologies, there is increased contact between such as the organic matter and the active biomass that effectively degrades it[[Anaerobic Baffled Reactor (ABR)| Anaerobic Baffled Reactor (ABR)]] (ABR, T.3).
The Anaerobic Filter can be filters are usually operated in either upflow or downflow mode. The upflow mode is recommended because there is less risk that the fixed biomass will be washed out. The water level should cover the filter media by at least 0.3m 3 m to guarantee an even flow regime. The hydraulic retention time (HRT) is the most important design parameter influencing filter performance. An HRT of 12 to 36 hours is recommended. The ideal filter should have a large surface area for bacteria to grow, with pores large enough to prevent clogging. The surface area ensures increased contact between the organic matter and the attached biomass that effectively degrades it. Ideally, the material should provide between 90 to 300 m2 of surface area per m3 of occupied reactor volume. Typical filter material sizes range from 12 to 55 mm in diameter. Materials commonly used include gravel, crushed rocks or bricks, cinder, pumice, or specially formed plastic pieces, depending on local availability.
Studies have shown that The connection between the HRT is the most important design parameter influencing filter performance. An HRT of 0chambers can be designed either with vertical pipes or baffles.5 Accessibility to 1.5 days is a typical and recommended. A maximum surface-loading all chambers (i.e. flow per areathrough access ports) rate of 2is necessary for maintenance.8m/d has proven to The tank should be suitable. Suspended solids and BOD removal can be as high as 85% vented to 90% but is typically between 50% and 80%. Nitrogen removal is limited allow for controlled release of odorous and normally does not exceed 15% in terms of total nitrogen (TN)potentially harmful gases.
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{{procontable | pro=
- Resistant to organic and hydraulic shock loads. <br> - No electrical energy is required. <br> - Can be built and repaired with locally available materials. Low operating costs <br> - Long service life. <br> - High reduction of BOD and solids <br>- Low sludge production; the sludge is stabilized <br>- Moderate capital costs, moderate operating costs depending on emptying; area requirement (can be lowered depending on number of users. built underground) <br> - High reduction of BOD and solids. | con=- Requires constant source expert design and construction <br>- Low reduction of water. pathogens and nutrients <br> - Effluent and sludge require secondary further treatment and/or appropriate discharge. <br> - Low reduction Risk of pathogens clogging, depending on pre- and nutrients. primary treatment <br> - Requires expert design Removing and construction. <br> - Long start up time.cleaning the clogged filter media is cumbersome
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==Adequacy=Appropriateness=== This technology is easily adaptable and can be applied at the household level , in small neighbourhoods or even in bigger catchment areas. It is most appropriate where a small neighbourhood (refer to Technology Information Sheet T2: Anaerobic Filter for information about applying an Anaerobic Filter at the community level)relatively constant amount of blackwater and greywater is generated. An Anaerobic Filter The anaerobic filter can be designed used for secondary treatment, to reduce the organic loading rate for a single house subsequent aerobic treatment step, or a group of houses that are using a lot of water for clothes washing, showering, and toilet flushing. It is only appropriate if water use is high, ensuring that the supply of wastewater is constantpolishing.
The Anaerobic Filter will not operate at full capacity This technology is suitable for six to nine months after installation because of areas where land may be limited since the long start up time required tank is most commonly installed underground and requires a small area. Accessibility by vacuum truck is important for the anaerobic biomass to stabilizedesludging. Therefore, the Anaerobic Filter technology should not filters can be used when installed in every type of climate, although the need for a treatment technology efficiency is immediatelower in colder climates. Once working They are not efficient at full capacity it is a stable technology that removing nutrients and pathogens. Depending on the filter material, however, complete removal of worm eggs may be achieved. The effluent usually requires little attentionfurther treatment.
===Health Aspects/Acceptance=== Under normal operating conditions, users do not come in contact with the influent or effluent. Effluent, scum and sludge must be handled with care as they contain high levels of pathogenic organisms. The Anaerobic Filter effluent contains odorous compounds that may have to be removed in a further polishing step. Care should be watertight but it should still taken to design and locate the facility such that odours do not be constructed in areas with high groundwater tables or where there is frequent floodingbother communitymembers.
Depending ===Operation & Maintenance=== An anaerobic filter requires a start-up period of 6 to 9 months to reach full treatment capacity since the slow growing anaerobic biomass first needs to be established on land availability and the hydraulic gradient of the sewer (if applicable)filter media. To reduce startup time, the Anaerobic Filter filter can be built above or below groundinoculated with anaerobic bacteria, e.g., by spraying Septic Tank sludge onto the filter material. It can The flow should be installed in every type gradually increased over time. Because of climatethe delicate ecology, although care should be taken not to discharge harsh chemicals into the efficiency will be affected in colder climatesanaerobic filter.
==Health Aspects/Acceptance==Scum and sludge levels need to be monitored to ensure that the tank is functioning well. Over time, solids will clog the pores of the filter. As well, the growing bacterial mass will become too thick, break off and eventually clog pores. When the efficiency decreases, the filter must be cleaned. This is done by running the system in reverse mode (backwashing) or by removing and cleaning the filter material. Anaerobic filter tanks should be checked from time to time to ensure that they are watertight.
Because the Anaerobic Filter unit is underground===References===* Morel, users do not come in contact with the influent or effluentA. Infectious organisms are not sufficiently removedand Diener, so the effluent should be further treated or discharged properlyS. (2006). [https://www.susana.org/_resources/documents/default/2-947-en-greywater-management-2006. The effluent, despite treatment, will still have a strong odour pdf Greywater Management in Low and care should be taken to design and locate the facility such that odours do not bother community membersMiddle-Income Countries]. To prevent the release Review of potentially harmful gasesDifferent Treatment Systems for Households or Neighbourhoods. Eawag (Department Sandec), the Anaerobic Filters should be vented. The desludging of the filter is hazardous and appropriate safety precautions should be takenDübendorf, CH.
==Maintenance==* von Sperling, M. and de Lemos Chernicharo, C. A. (2005). [https://www.iwapublishing.com/sites/default/files/ebooks/9781780402734.pdf Biological Wastewater Treatment in Warm Climate Regions, Volume One]. IWA Publishing, London, UK. pp. 728-804.
Active bacteria must be added to start up the Anaerobic Filter* Ulrich, A. The active bacteria can come from sludge from a septic tank that has been sprayed onto the filter material(Ed. The flow should be gradually increased over time), Reuter, and the filter should be working at maximum capacity within six to nine monthsS. (Ed.), Gutterer, B. (Ed. With time), Sasse, the solids will clog the pores of the filterL. As well, the growing bacterial mass will become too thick Panzerbieter, T. and will break off and clog poresReckerzügel, T. (2009). [https://wedc-knowledge. A sedimentation tank before the filter is required to prevent the majority of settleable solids from entering the unitlboro. Some clogging increases the ability of the filter to retain solidsac. When the efficiency of the filter decreases, it must be cleaneduk/resources/books/DEWATS_-_Chapter_01. Running the system pdf Decentralised Wastewater Treatment Systems (DEWATS) and Sanitation in reverse mode to dislodge accumulated biomass and particles cleans the filtersDeveloping Countries. A Practical Guide]. AlternativelyWEDC, Loughborough University, the filter material can be removed and cleanedLeicestershire, UK.(Design summary including Excel spreadsheets for design calculations)
===Acknowledgements===
{{:Acknowledgements Sanitation}}
==References and external links==
* Morel, A. and Diener, S. (2006). Greywater Management in Low and Middle-Income Countries, Review of different treatment systems for households or neighbourhoods. Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland. (Short summary including case studies, page 28.)
* Polprasert, C. and Rajput, VS. (1982). Environmental Sanitation Reviews: Septic Tank and Septic Systems. Environmental Sanitation Information Center, AIT, Bangkok, Thailand. pp 68–74. (Short design summary.)
* Sasse, L. (1998). DEWATS: Decentralised Wastewater Treatment in Developing Countries. BORDA, Bremen Overseas Research and Development Association, Bremen, Germany. (Design summary including Excel-based design program.)
* von Sperlin, M. and de Lemos Chernicharo, CA. (2005). Biological Wastewater Treatment in Warm Climate Regions. Volume One. IWA, London. pp 728–804. (Detailed design instructions.)
* Vigneswaran, S., et al. (1986). Environmental Sanitation Reviews: Anaerobic Wastewater Treatment-Attached growth and Sludge blanket process. Environmental Sanitation Information Center, AIT Bangkok, Thailand. (Design criteria and diagrams in Chapter 2.)