2.4.1 Anaerobic baffled reactor with biogas capture

Decentralized Wastewater Management at Adarsh College Badalapur Maharashtra India (Source: Zimmermann, 2009)

The Anaerobic Baffled Reactor (ABR) is a treatment system comprising multiple chambers and requires a settler as a pre-treatment option.

In each chamber, suspended and dissolved solids undergo anaerobic degradation. As the influent passes through, the sludge settles at the bottom of each chamber, and the microorganism breaks down the organic matter. It’s best to have four and not more than six chambers for optimal performance, allowing better interaction between microorganisms and wastewater. While ABRs are usually built without biogas capture, capturing the methane produced during the process is necessary for climate protection. ABRs are commonly used alongside other treatment steps and are well-suited for wastewater with a high concentration of suspended solids (TSS) and easily degradable organic compounds, indicated by a narrow COD/BOD ratio.

The table highlights the pros and cons of an anaerobic baffled reactor.

This system is easy to use and has a relatively low operating costExpert design and skilled labour are required
Suitable for smaller and larger settlementsWell-organized O&M is required
Long service lifeLow reduction of pathogens and nutrients
Capturing and utilizing biogas can lead to a reduction in greenhouse gas emissionsSusceptibility to temperature fluctuations
Capable of withstanding organic and hydraulic shock loadsEffluent and sludge require further treatment and/or appropriate discharge
High reduction of BODTreatment performance is temperature-dependent
Space saving if undergroundLong start-up time
Low sludge production 
Renewable energy source if captured and utilized 
Adopted from: (Eawag) (SANIMAS, 2005)
Pros and Cons of Anaerobic Baffled Reactor

For further information, please click on the Materials tab at the top of the page.

Further Reading:

  • Decentralised Wastewater Management at Adarsh College Badlapur, Maharashtra, India (Link)
  • BIOGAS FOR SANITATION. Closing the Nutrient Loop through Sanitation, Hygiene, Environmental Protection and Food Security in Lesotho (Link)