4.4.6 Planning Sludge Management

For a digester to function efficiently, it’s important to regularly remove the solid residue known as sludge that remains after the anaerobic digestion process. Failure to remove sludge over time can lead to its accumulation, taking up valuable space and decreasing the effective volume of the digester. This can result in a decline in both treatment performance and biogas generation, making desludging a critical step in maintaining the effectiveness of a digester.

Because helminth eggs and protozoa are found in the sludge at the bottom, every plant requires consideration on how to manage the sludge, after it has been dislodged.

When determining how to manage the sludge, the global WASH cluster’s “Sanitation Quality Standards for Emergencies” offers guidance.

Rationale for Solid Management (WASH Cluster, 2021)