Difference between revisions of "Anaerobic Baffled Reactor (ABR) 1"

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{|style="float: left;"
<!-- table at top of page with logo, picture, Application level, Management level, and input-output tables -->
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|{{Language-box|english_link=Anaerobic Baffled Reactor (ABR)|french_link=Réacteur_anaérobie_à_chicanes_(semi-)_centralisés|spanish_link=Estanques_de_ Estabilizacion_de_Desperdicios|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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{|width="100%"
 
{|width="100%"
|style="width:50%;"|{{santable_new|
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|style="width:50%;"|
sys1=[[(Semi-) Centralized Treatment System |7]]|
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{{santable_new|
sys2=|
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sys1=[[Single Pit System|1]]|
sys3=|
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sys2=[[Blackwater Treatment System with Infiltration|6]]|
sys4=|
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sys3=[[Blackwater Treatment System with Effluent Transport|7]]|
sys5=|
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sys4=[[Blackwater Transport to (Semi-) Centralized Treatment System|8]]|
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sys5=[[Sewerage System with Urine Diversion|9]]|
 
sys6=|
 
sys6=|
 
sys7=|
 
sys7=|
 
sys8=|
 
sys8=|
pic=Waste_stabilization_ponds.png|
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sys9=|
ApplHousehold=XX|
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pic=anaerobic baffled reactor.png|
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ApplHousehold=X|
 
ApplNeighbourhood=XX|
 
ApplNeighbourhood=XX|
 
ApplCity=|
 
ApplCity=|
ManHousehold=XX|
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ManHousehold=X|
 
ManShared=XX|
 
ManShared=XX|
 
ManPublic=XX|
 
ManPublic=XX|
Input1=Blackwater|Input2=Greywater |Input3= | Input4= |Input5=|
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Input1=Blackwater|Input2=Greywater |Input3=Brownwater | Input4=Effluent |Input5=|
Output1= Faecal Sludge | Output2=Effluent | Output3= | Output4= | Output5=
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Output1= Sludge | Output2=Effluent | Output3= | Output4= | Output5=
|english_link=Semi_centralised_Anaerobic_Baffled_Reactor
 
|french_link=Réacteur_anaérobie_à_chicanes_(semi-)_centralisés
 
|spanish_link=Estanques_de_ Estabilizacion_de_Desperdicios
 
 
}}
 
}}
|[[Image:Waste_stabilization_ponds.png |right|300px]]
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[[Image:Icon_waste_stabilization_ponds.png |right|80px]]
 
[[Image:Icon_waste_stabilization_ponds.png |right|80px]]
'''An Anaerobic Baffled Reactor (ABR) is an improved septic tank because of the series of baffles over which the incoming wastewater is forced to flow. The increased contact time with the active biomass (sludge) results in improved treatment.'''
+
'''An anaerobic baffled reactor (ABR) is an improved [[Septic Tank]] (S.9) with a series of baffles under which the wastewater is forced to flow. The increased contact time with the active biomass (sludge) results in improved treatment.'''
 +
 
 +
The upflow chambers provide enhanced removal and digestion of organic matter. BOD may be reduced by up to 90%, which is far superior to its removal in a conventional Septic Tank.
  
The majority of settleable solids are removed in the
+
===Design Considerations===
sedimentation chamber at the beginning of the ABR,
+
The majority of settleable solids are removed in a sedimentation chamber in front of the actual ABR. Small-scale, stand-alone units typically have an integrated settling compartment (as shown in S.10), but primary sedimentation can also take place in a separate [[Settler]] (T.1) or another preceding technology (e.g., existing [[Septic Tank|Septic Tanks]]). Designs without a settling compartment are of particular interest for (Semi-) Centralized Treatment plants that combine the ABR with another technology for primary settling, or where prefabricated, modular units are used. Typical inflows range from 2 to 200 m3 per day.  
which typically represents 50% of the total volume.
 
The up-flow chambers provide additional removal and
 
digestion of organic matter: BOD may be reduced by
 
up to 90%, which is far superior to that of a conventional
 
septic tank. As sludge is accumulating, desludging
 
is required every 2 to 3 years. Critical design parameters
 
include a hydraulic retention time (HRT)
 
between 48 to 72 hours, up-flow velocity of the wastewater
 
less than 0.6m/h and the number of up-flow
 
chambers (2 to 3).
 
  
 +
Critical design parameters include a hydraulic retention time (HRT) between 48 to 72 hours, upflow velocity of the wastewater below 0.6 m/h and the number of upflow chambers (3 to 6). 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. Usually, the biogas produced in an ABR through anaerobic digestion is not collected because of its insufficient amount. The tank should be vented to allow for controlled release of odorous and potentially harmful gases.
  
{| border="1" cellpadding="5" cellspacing="0" align="center"
+
 
 +
{| border="1" cellpadding="5" cellspacing="0" align="none"
 
|-
 
|-
 
! width="50%" style="background:#efefef;" | Advantages
 
! width="50%" style="background:#efefef;" | Advantages
 
! style="background:#f0f8ff;" | Disadvantages
 
! style="background:#f0f8ff;" | Disadvantages
 
|-
 
|-
| valign="top" |- Resistant to organic and hydraulic shock loads. <br>
+
| valign="top" |
- No electrical energy required. <br>
+
- Resistant to organic and hydraulic shock loads <br>
- Greywater can be managed concurrently. <br>
+
- No electrical energy is required <br>
- Can be built and repaired with locally available materials. <br>
+
- Low operating costs <br>
- Long service life. <br>
+
- Long service life <br>
- No real problems with flies or odours if used correctly. <br>
+
- High reduction of BOD <br>
- High reduction of organics. <br>
+
- Low sludge production; the sludge is stabilized <br>
- Moderate capital costs, moderate operating costs depending on emptying; can be low cost depending on number of users.
+
- Moderate area requirement (can be built underground)
| valign="top" | - Requires constant source of water. <br>
+
| valign="top" |  
- Effluent require secondary treatment and/or appropriate discharge. <br>
+
- Requires expert design and construction <br>
- Low reduction pathogens. <br>
+
- Low reduction of pathogens and nutrients <br>
- Requires expert design and construction. <br>
+
- Effluent and sludge require further treatment and/or appropriate discharge
- Pre-treatment is required to prevent clogging.
 
 
|}
 
|}
  
  
===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. A (semi-) centralized ABR is appropriate when there is a pre-existing Conveyance technology, such as a [[Simplified Sewer]] (C.4).
  
This technology is easily adaptable and
+
This technology is suitable for areas where land may be limited since the tank is most commonly installed underground and requires a small area. However, a vacuum truck should be able to access the location because the sludge must be regularly removed (particularly from the settler). ABRs can be installed in every type of climate, although the efficiency is lower in colder climates. They are not efficient at removing nutrients and pathogens. The effluent usually requires further treatment.
can be applied at the household level or for a small neighbourhood. A (semi-) centralized ABR is appropriate when there is
 
an already existing Conveyance technology, such as a
 
[[Solids-free Sewer]]. This technology is also appropriate
 
for areas where land may be limited since the
 
tank is installed underground and requires a small area.
 
It should not be installed where there is a high groundwater
 
table as infiltration will affect the treatment efficiency
 
and contaminate the groundwater.
 
  
This technology can be efficiently designed for a daily
+
===Health Aspects/Acceptance===
inflow of up to 200,000L/day. The ABR will not operate
+
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 effluent contains odorous compounds that may have to be removed in a further polishing step. Care should be taken to design and locate the facility such that odours do not bother community members.
at full capacity for several months after installation
 
because of the long start up time required for the
 
anaerobic digestion of the sludge. Therefore, the ABR
 
technology should not be used when the need for a
 
treatment system is immediate.
 
  
Because the ABR must be emptied regularly, a vacuum
+
===Operation & Maintenance===
truck should be able to access the location.
+
An ABR requires a start-up period of several months to reach full treatment capacity since the slow growing anaerobic biomass first needs to be established in the reactor. To reduce startup time, the ABR can be inoculated with anaerobic bacteria, e.g., by adding fresh cow dung or Septic Tank sludge. The added stock of active bacteria can then multiply and adapt to the incoming wastewater. Because of the delicate ecology, care should be taken not to discharge harsh chemicals into the ABR.
ABRs can be installed in every type of climate although
 
the efficiency will be affected in colder climates.
 
  
===Health Aspects/Acceptance===
+
Scum and sludge levels need to be monitored to ensure that the tank is functioning well. Process operation in general is not required, and maintenance is limited to the removal of accumulated sludge and scum every 1 to 3 years. This is best done using a [[Motorized Emptying and Transport|Motorized Emptying and Transport]] technology (C.3). The desludging frequency depends on the chosen pre-treatment steps, as well as on the design of the ABR. ABR tanks should be checked from time to time to ensure that they are watertight.
  
Although the removal
+
===References===
of pathogens is not high, the ABR is contained so
+
* Bachmann, A., Beard, V. L. and McCarty, P. L. (1985). [https://www.sciencedirect.com/science/article/abs/pii/0043135485903306 Performance Characteristics of the Anaerobic Baffled Reactor] (academic access required). Water Research 19 (1): 99-106.
users do not come in contact with any of the wastewater
 
or disease causing pathogens. Effluent and sludge must be handled with care as they contain high levels of
 
pathogenic organisms.
 
To prevent the release of potentially harmful gases, the
 
tank should be vented.
 
  
===Maintenance===
+
* Barber, W. P. and Stuckey, D. C. (1999). [https://www.sciencedirect.com/science/article/abs/pii/S0043135498003716 The Use of the Anaerobic Baffled Reactor (ABR) for Wastewater Treatment: A Review] (academic access required). Water Research 33 (7): 1559-1578.
  
ABR tanks should be checked to
+
* Foxon, K. M., Buckley, C. A., Brouckaert, C. J., Dama, P., Mtembu, Z., Rodda, N., Smith, M., Pillay, S., Arjun, N., Lalbahadur, T. and Bux, F. (2006). [https://sswm.info/sites/default/files/reference_attachments/FOXON%20et%20al%202006%20Evaluation%20of%20the%20Anaerobic%20Baffled%20Reactor%20for%20Sanitation%20in%20Dense%20Peri%20urban%20Settlements.pdf Evaluation of the Anaerobic Baffled Reactor for Sanitation in Dense Peri-urban Settlements]. WRC Report No 1248/01/06, Water Research Commission, Pretoria, ZA.
ensure that they are watertight and the levels of the
+
:Available at: [http://www.wrc.org.za wrc.org.za]
scum and sludge should be monitored to ensure that
 
the tank is functioning well. Because of the delicate
 
ecology, care should be taken not to discharge harsh
 
chemicals into the ABR.
 
The sludge should be removed annually using a vacuum
 
truck to ensure proper functioning of the ABR.
 
 
 
===References===
 
  
* Bachmann, A., Beard, VL. and McCarty, PL. (1985). Performance Characteristics of the Anaerobic Baffled Reactor. Water Research 19 (1): 99–106.
+
* Foxon, K. M., Pillay, S., Lalbahadur, T., Rodda, N., Holder, F. and Buckley, C. A. (2004). [https://www.researchgate.net/publication/228632608_The_anaerobic_baffled_reactor_ABR_An_appropriate_technology_for_on-site_sanitation The Anaerobic Baffled Reactor (ABR): An Appropriate Technology for on-Site Sanitation]. Water SA 30 (5) (Special Edition).
  
* Foxon, KM., et al. (2004). The anaerobic baffled reactor (ABR): An appropriate technology for on-site sanitation. Water SA 30 (5) (Special edition). Available: www.wrc.org.za
+
* Stuckey, D. C. (2010). Anaerobic Baffled Reactor (ABR) for Wastewater Treatment. In: Environmental Anaerobic Technology. Applications and New Developments, H. H. P. Fang (Ed.), Imperial College Press, London, UK.
  
* Sasse, L. (1998). DEWATS: Decentralised Wastewater Treatment in Developing Countries. BORDA, Bremen. Overseas Research and Development Association, Bremen, Germany. (Design summary including and Excel®-based design program.)
+
* 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.
  
 
===Acknowledgements===
 
===Acknowledgements===
 
{{:Acknowledgements Sanitation}}
 
{{:Acknowledgements Sanitation}}

Latest revision as of 20:06, 23 September 2020

English Français Español भारत മലയാളം தமிழ் 한국어 中國 Indonesia Japanese
Applicable in systems:
1, 6 , 7 , 8 , 9
Level of Application
Household X
Neighbourhood XX
City

 

Inputs
Blackwater, Greywater, Brownwater, Effluent


Level of management
Household X
Shared XX
Public XX

 

Outputs
Sludge, Effluent
Anaerobic baffled reactor.png




Icon waste stabilization ponds.png

An anaerobic baffled reactor (ABR) is an improved Septic Tank (S.9) with a series of baffles under which the wastewater is forced to flow. The increased contact time with the active biomass (sludge) results in improved treatment.

The upflow chambers provide enhanced removal and digestion of organic matter. BOD may be reduced by up to 90%, which is far superior to its removal in a conventional Septic Tank.

Design Considerations

The majority of settleable solids are removed in a sedimentation chamber in front of the actual ABR. Small-scale, stand-alone units typically have an integrated settling compartment (as shown in S.10), but primary sedimentation can also take place in a separate Settler (T.1) or another preceding technology (e.g., existing Septic Tanks). Designs without a settling compartment are of particular interest for (Semi-) Centralized Treatment plants that combine the ABR with another technology for primary settling, or where prefabricated, modular units are used. Typical inflows range from 2 to 200 m3 per day.

Critical design parameters include a hydraulic retention time (HRT) between 48 to 72 hours, upflow velocity of the wastewater below 0.6 m/h and the number of upflow chambers (3 to 6). 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. Usually, the biogas produced in an ABR through anaerobic digestion is not collected because of its insufficient amount. The tank should be vented to allow for controlled release of odorous and potentially harmful gases.


Advantages Disadvantages

- Resistant to organic and hydraulic shock loads
- No electrical energy is required
- Low operating costs
- Long service life
- High reduction of BOD
- Low sludge production; the sludge is stabilized
- Moderate area requirement (can be built underground)

- Requires expert design and construction
- Low reduction of pathogens and nutrients
- Effluent and sludge require further treatment and/or appropriate discharge


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. A (semi-) centralized ABR is appropriate when there is a pre-existing Conveyance technology, such as a Simplified Sewer (C.4).

This technology is suitable for areas where land may be limited since the tank is most commonly installed underground and requires a small area. However, a vacuum truck should be able to access the location because the sludge must be regularly removed (particularly from the settler). ABRs can be installed in every type of climate, although the efficiency is lower in colder climates. They are not efficient at removing nutrients and pathogens. The effluent usually requires further 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 effluent contains odorous compounds that may have to be removed in a further polishing step. Care should be taken to design and locate the facility such that odours do not bother community members.

Operation & Maintenance

An ABR requires a start-up period of several months to reach full treatment capacity since the slow growing anaerobic biomass first needs to be established in the reactor. To reduce startup time, the ABR can be inoculated with anaerobic bacteria, e.g., by adding fresh cow dung or Septic Tank sludge. The added stock of active bacteria can then multiply and adapt to the incoming wastewater. Because of the delicate ecology, care should be taken not to discharge harsh chemicals into the ABR.

Scum and sludge levels need to be monitored to ensure that the tank is functioning well. Process operation in general is not required, and maintenance is limited to the removal of accumulated sludge and scum every 1 to 3 years. This is best done using a Motorized Emptying and Transport technology (C.3). The desludging frequency depends on the chosen pre-treatment steps, as well as on the design of the ABR. ABR tanks should be checked from time to time to ensure that they are watertight.

References

Available at: wrc.org.za
  • Stuckey, D. C. (2010). Anaerobic Baffled Reactor (ABR) for Wastewater Treatment. In: Environmental Anaerobic Technology. Applications and New Developments, H. H. P. Fang (Ed.), Imperial College Press, London, UK.

Acknowledgements

Eawag compendium cover.png

The material on this page was adapted from:

Elizabeth Tilley, Lukas Ulrich, Christoph Lüthi, Philippe Reymond and Christian Zurbrügg (2014). Compendium of Sanitation Systems and Technologies, published by Sandec, the Department of Water and Sanitation in Developing Countries of Eawag, the Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.

The 2nd edition publication is available in English. French and Spanish are yet to come.