A pH drop in an aerobic digester can be caused by ____________.

A drop in pH in an aerobic digester can be attributed to nitrification or the buildup of carbon dioxide (CO2). This is because nitrification is a microbial process carried out by specific bacteria that convert ammonia into nitrate. During this process, hydrogen ions (H+) are released, which can lead to a decrease in pH, making the environment more acidic. Additionally, when organic matter is decomposed during digestion, carbon dioxide is produced as a byproduct. An increase in CO2 levels can also contribute to lower pH levels, as CO2 can combine with water to form carbonic acid, further reducing pH.

Both of these processes highlight the biochemical complexity occurring in aerobic digesters and the importance of maintaining a balanced pH for optimal microbial activity. This is crucial because the effectiveness of the digestion process relies heavily on the right pH levels to support the growth and activity of beneficial bacteria.