Florida Wastewater Practice Test

When an anaerobic digester is operating correctly, the volatile acid to alkalinity ratio should be?

1. 0.01 to 0.1

2. 0.1 to 1.0

3. 1.0 to 2.0

4. 2.0 to 3.0

The correct answer is: 0.1 to 1.0

In the context of anaerobic digestion, the volatile acid to alkalinity ratio is a critical parameter to monitor for optimal digester performance. When the ratio falls within the range of 0.1 to 1.0, it indicates a balanced environment where the production of volatile fatty acids is appropriately matched by the buffering capacity provided by alkalinity. This balance is essential for maintaining stable digestion and effective breakdown of organic matter. A ratio within this range suggests that microbial populations are functioning well, enabling them to process the incoming organic material without overwhelming the system with unmanaged acid buildup. When volatile acid levels are too high relative to alkalinity, the system may become acidic, leading to a condition known as acidogenesis, which can inhibit bacterial activity and potentially shut down the digestion process. Maintaining this 0.1 to 1.0 ratio is vital for the health of the anaerobic digester and ensuring the efficient production of biogas. Thus, this range serves as a key indicator of operational stability and successful digestion processes.