4.3 Feedstock quality

To ensure effective treatment, it is crucial to have a well-designed system. The quality of the feedstock must be assessed, and if there is no local information available, a characterisation study can provide a more comprehensive understanding. Consulting relevant literature may be helpful for smaller projects without the resources to conduct a study. However, a characterisation study is strongly recommended for larger projects as a necessary step during the feasibility phase.

During Module 3, we discussed the crucial parameters for designing an anaerobic digester. Can you recall them?

  • Temperature
  • Total and Volatile Solids or Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD)
  • Total Carbon
  • Total Nitrogen
  • Biological Methane Potential (BMP)

When designing a treatment unit, additional parameters must be considered to determine the available options for post-treatment. It is recommended to refer to national guidelines for either disposal or reuse, depending on the type of effluent management. If no national laws exist, it is recommended to adhere to sanitation quality standards for emergencies (Link).

The type of sampling will depend on how the biogas digester is integrated.

For instance, when connecting the biogas digester to a toilet, one can place a barrel inside the pit latrine for 24 hours and collect the contents with the core sampler.

If the unit is semi-centralized, the faecal sludge sample can be obtained from the truck at the treatment or disposal location.

Please refer to the Materials tab at the top of the page for guidance on conducting a characterisation study.

Further Reading:

  • Sampling for faecal sludge and other liquid wastes in emergency settings (Link)
  • Methods for Faecal Sludge Analysis – Sampling p. 55 – 83 (Link 
  • Methods for Faecal Sludge Analysis – Characterisation p. 236 – 391 (Link)  
  • Waste Characterization and Quantification with Projections for the Future (Link)