<!{|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 }}|}{|width="100%"|style="width:50%;"|{{santablesantable_new|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|
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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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[[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.'''
This <br>With this technology consists of a sedimentation tank (or [[Septic Tank]]) followed by one or more filter chambers. Filter material commonly used includes gravel, crushed rockssuspended solids and BOD removal can be as high as 90%, cinder, or specially formed plastic pieces. Typical filter material sizes range from 12 to 55mm in diameter. Ideally, the material will provide but is typically between 90 to 300m2 of surface area per 1m3 of reactor volume50% and 80%. By providing a large surface area for the bacterial mass, there Nitrogen removal is increased contact between the organic matter limited and the active biomass that effectively degrades itnormally does not exceed 15% in terms of total nitrogen (TN).
===Design Considerations=== Pre- and primary treatment is essential to remove solids and garbage that may clog the filter. The Anaerobic Filter majority of settleable solids are removed in a sedimentation chamber in front of the anaerobic filter. Small-scale, stand-alone units typically have an integrated settling compartment, but primary sedimentation can be operated also take place in either upflow a separate [[Settler]] (T.1) or downflow modeanother preceding technology (e. The upflow mode is recommended because there is less risk g., existing [[Septic Tank]]s). Designs without a settling compartment (as shown in T.4) are of particular interest for (Semi-) Centralized Treatment plants that combine the fixed biomass will be washed out. The water level should cover anaerobic filter with other technologies, such as the filter media by at least 0[[Anaerobic Baffled Reactor (ABR)| Anaerobic Baffled Reactor (ABR)]] (ABR, T.3m to guarantee an even flow regime3).
Studies have shown Anaerobic filters are usually operated in upflow mode because there is less risk that the fixed biomass will be washed out. The water level should cover the filter media by at least 0.3 m to guarantee an even flow regime. The hydraulic retention time (HRT ) is the most important design parameter influencing filter performance. An HRT of 0.5 12 to 1.5 days 36 hours is a typical and recommended. A maximum The ideal filter should have a large surface-loading (iarea for bacteria to grow, with pores large enough to prevent clogging.eThe surface area ensures increased contact between the organic matter and the attached biomass that effectively degrades it. flow Ideally, the material should provide between 90 to 300 m2 of surface area per area) rate m3 of 2occupied reactor volume.8m/d has proven Typical filter material sizes range from 12 to be suitable55 mm in diameter. Suspended solids and BOD removal can be as high as 85% to 90% but is typically between 50% and 80%. Nitrogen removal is limited and normally does not exceed 15% in terms of total nitrogen (TN)Materials commonly used include gravel, crushed rocks or bricks, cinder, pumice, or specially formed plastic pieces, depending on local availability.
The connection between the chambers can be designed either with vertical pipes or baffles. Accessibility to all chambers (through access ports) is necessary for maintenance. The tank should be vented to allow for controlled release of odorous and 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 relatively constant amount of blackwater and greywater is generated. The anaerobic filter can be used for secondary treatment, to reduce the organic loading rate for a subsequent aerobic treatment step, or for polishing.
This technology is easily adaptable and can suitable for areas where land may be applied at limited since the household level or tank is most commonly installed underground and requires a small neighbourhood (refer to Technology Information Sheet T2: Anaerobic Filter area. Accessibility by vacuum truck is important for information about applying an Anaerobic Filter at the community level)desludging. An Anaerobic Filter filters can be designed for a single house or a group installed in every type of houses that climate, although the efficiency is lower in colder climates. They are using a lot of water for clothes washing, showering, not efficient at removing nutrients and toilet flushingpathogens. It is only appropriate if water use is highDepending on the filter material, however, ensuring that the supply complete removal of wastewater is constantworm eggs may be achieved. The effluent usually requires further treatment.
The Anaerobic Filter will ===Health Aspects/Acceptance=== Under normal operating conditions, users do not operate at full capacity for six to nine months after installation because come in contact with the influent or effluent. Effluent, scum and sludge must be handled with care as they contain high levels of the long start up time required for the anaerobic biomass pathogenic organisms. The effluent contains odorous compounds that may have to stabilizebe removed in a further polishing step. Therefore, the Anaerobic Filter technology Care should not be used when taken to design and locate the need for a treatment technology is immediate. Once working at full capacity it is a stable technology facility such that requires little attentionodours do not bother communitymembers.
===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 the filter media. To reduce startup time, the filter can be inoculated with anaerobic bacteria, e.g., by spraying Septic Tank sludge onto the filter material. The Anaerobic Filter flow should be watertight but it gradually increased over time. Because of the delicate ecology, care should still be taken not be constructed in areas with high groundwater tables or where there is frequent floodingto discharge harsh chemicals into the anaerobic filter.
Depending on land availability Scum and sludge levels need to be monitored to ensure that the tank is functioning well. Over time, solids will clog the hydraulic gradient pores of the sewer (if applicable)filter. As well, the growing bacterial mass will become too thick, break off and eventually clog pores. When the efficiency decreases, the Anaerobic Filter can filter must be built above or below groundcleaned. It can be installed This is done by running the system in every type of climate, although reverse mode (backwashing) or by removing and cleaning the efficiency will filter material. Anaerobic filter tanks should be affected in colder climateschecked from time to time to ensure that they are watertight.
==Health Aspects/Acceptance=References===* Morel, A. and Diener, S. (2006). [https://www.susana.org/_resources/documents/default/2-947-en-greywater-management-2006.pdf Greywater Management in Low and Middle-Income Countries]. Review of Different Treatment Systems for Households or Neighbourhoods. Eawag (Department Sandec), Dübendorf, CH.
Because the Anaerobic Filter unit is underground* von Sperling, users do not come M. and de Lemos Chernicharo, C. A. (2005). [https://www.iwapublishing.com/sites/default/files/ebooks/9781780402734.pdf Biological Wastewater Treatment in contact with the influent or effluent. Infectious organisms are not sufficiently removedWarm Climate Regions, so the effluent should be further treated or discharged properlyVolume One]. The effluentIWA Publishing, despite treatmentLondon, will still have a strong odour and care should be taken to design and locate the facility such that odours do not bother community membersUK. To prevent the release of potentially harmful gases, the Anaerobic Filters should be ventedpp. The desludging of the filter is hazardous and appropriate safety precautions should be taken728-804.
==Maintenance==* 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. (Design summary including Excel spreadsheets for design calculations)
Active bacteria must be added to start up the Anaerobic Filter. The active bacteria can come from sludge from a septic tank that has been sprayed onto the filter material. The flow should be gradually increased over time, and the filter should be working at maximum capacity within six to nine months. With time, the solids will clog the pores of the filter. As well, the growing bacterial mass will become too thick and will break off and clog pores. A sedimentation tank before the filter is required to prevent the majority of settleable solids from entering the unit. Some clogging increases the ability of the filter to retain solids. When the efficiency of the filter decreases, it must be cleaned. Running the system in reverse mode to dislodge accumulated biomass and particles cleans the filters. Alternatively, the filter material can be removed and cleaned. ===Acknowledgements===
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==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.)