Texas Class C Wastewater Treatment License Test 2025 – 400 Free Practice Questions to Pass the Exam

Poor quality supernatant liquor in a digester can arise from digester overload due to the inability of the system to effectively break down and digest the organic material present. When the digester exceeds its capacity, it may not provide adequate retention time for the microbes to stabilize the waste, leading to incomplete digestion. This can result in higher concentrations of soluble organic compounds and other byproducts in the supernatant, ultimately compromising its quality.

In an overloaded digester, the balance of microbial populations can also shift, which may detract from their efficiency in breaking down waste. This creates conditions that can lead to the release of undesirable substances and a reduction in overall treatment performance.

Other factors like low temperature, excessive airflow, or insufficient mixing can also impact digester performance but may not directly correlate with the specific issue of supernatant quality in the same manner as digester overload does. Low temperatures can slow down microbial activity, while excessive airflow might cause oxygenation that is not conducive to anaerobic digestion. Insufficient mixing can lead to stratification and poor distribution of material but does not inherently lead to the same level of impact as an overloaded digester on supernatant quality.