CWEA Advanced Water Treatment Practice Test

Aeration plays a fundamental role in secondary wastewater treatment primarily by promoting the growth of microbes. This process involves introducing air or oxygen into the wastewater, which enhances the aerobic conditions necessary for microbial activity. Bacteria and other microorganisms utilize oxygen to break down organic matter in the sewage, effectively decomposing pollutants and reducing biochemical oxygen demand (BOD).

By increasing the oxygen levels in the wastewater, aeration supports the metabolic processes of these microorganisms, allowing them to thrive and efficiently convert organic materials into carbon dioxide, water, and biomass. As a result, the overall treatment process becomes more effective, leading to cleaner effluent being discharged or further treated.

While aeration can influence sedimentation, eliminate odors, and may have some impact on pH, its primary and most significant function in secondary treatment is to foster an environment that supports microbial growth, which is essential for the biological treatment of wastewater.