What is likely to happen if too much sludge is added to an anaerobic digester?

When too much sludge is added to an anaerobic digester, the microbial balance within the system can be disrupted, leading to an overabundance of organic material that the microorganisms may struggle to process effectively. As a result, acid-producing bacteria can become dominant. These bacteria break down the organic matter and produce acids, which can lead to a decrease in the pH of the digester environment.

A drop in pH is problematic because anaerobic digestion typically operates optimally within a specific pH range (around neutral to slightly alkaline). If the pH becomes too low, it can hinder the activity of methanogens, the methane-producing bacteria essential for maintaining gas production. In such situations, the increase in acid production can lead to "acidification," negatively impacting the overall digestion process and efficiency.

This scenario underscores the importance of maintaining a balanced input of organic material in anaerobic digesters to ensure optimal microbial activity and process efficiency.