Tennessee Wastewater Operator Practice Exam

Which parameter is crucial to monitor in order to ensure proper digester feeding?

1. Feed VS load

2. pH levels

3. Temperature consistency

4. Sludge thickness

The correct answer is: Feed VS load

Monitoring the feed volatile solids (VS) load is crucial for ensuring proper digester feeding because it directly influences the digestion process and the efficiency of biogas production. The feed VS load refers to the amount of organic material, specifically volatile solids, introduced into the digester. Organic materials are broken down by microorganisms during anaerobic digestion, and the rate at which they are fed into the system must be carefully controlled. An appropriate feed VS load is essential for maintaining optimal microbial activity and preventing issues such as digester upset or insufficient biogas production. If the feed is too high, it can lead to overloading, resulting in reduced digestion efficiency or even system failure. Conversely, an inadequate feed load can starve the microorganisms, leading to decreased biogas output and less efficient treatment of the sludge. While parameters like pH levels, temperature consistency, and sludge thickness are important for the overall health of the digester and its operation, they do not directly correlate with the immediate need to ensure the correct amount of organic material is being introduced into the system for optimal performance. Each of these factors plays a supportive role in maintaining ideal conditions for digestion, but the feed VS load is specifically central to tracking and adjusting the feeding process itself.