What action should an operator take if ammonia rates are climbing steadily in an anaerobic digester?

When ammonia rates are climbing steadily in an anaerobic digester, reducing the organic loading rate is a critical response. An increase in ammonia concentrations can indicate that the anaerobic bacteria responsible for breaking down organic material are being overwhelmed by the quantity of feed being introduced into the digester. By reducing the organic loading rate, the system can alleviate stress on the microbial population, allowing them to effectively process the available substrates and maintain a balanced environment.

Lowering the organic loading rate helps to stabilize digestion processes, enhances microbial activity, and can facilitate a more effective conversion of organic matter. This is essential for controlling ammonia levels, as excessive ammonia can be toxic to anaerobic microorganisms, potentially leading to reduced digester performance and efficiency.

In contrast, options such as increasing mixing intensity, adding chemicals to neutralize ammonia, or replacing a portion of the digester content could either complicate the process or fail to address the underlying issue of excessive organic input, thereby not resolving the ammonia accumulation problem effectively.