ABC Wastewater Collection Level 2 Practice Exam 2025 – Complete Preparation Guide

The SOUR test, or Specific Oxygen Uptake Rate test, is an effective method for measuring the biological activity in a biological reactor. This test quantifies the rate at which microorganisms consume oxygen, which is directly correlated to their metabolic activity. By assessing the oxygen uptake over a specific time period, you can gain insight into how actively the microorganisms are breaking down organic materials in the wastewater treatment process.

Understanding the biological activity is crucial for optimizing the aeration process, as it helps operatives determine whether the oxygen supplied is adequate to support the microbial population's needs. This information can guide adjustments to aeration rates, ensuring that the wastewater treatment reaches optimal efficiency and efficacy.

Other tests listed, such as the SS (suspended solids), TKN (total Kjeldahl nitrogen), and VSS (volatile suspended solids), provide important information about the composition and concentration of solids in the wastewater but do not measure the biological activity or respiration rate of organisms in the same direct manner as the SOUR test. Thus, the SOUR test is the most suitable choice for evaluating biological activity and aeration.