Florida Wastewater Practice Test

What process occurs in the stabilization tank of a contact stabilization plant?

1. Filtration

2. Absorption

3. Precipitation

4. Evaporation

The correct answer is: Absorption

In a contact stabilization plant, the stabilization tank plays a crucial role in the treatment of wastewater by promoting the absorption process. During this stage, microorganisms in the wastewater interact with the organic matter present, allowing for the removal of pollutants through biological processes. Absorption involves the uptake of organic and inorganic substances by the microorganisms, which utilize these compounds for growth and energy. This process is essential for breaking down waste and reducing the biochemical oxygen demand (BOD) of the wastewater. The environment in the stabilization tank is conducive to the growth of these microorganisms, which thrive as they digest the organic material. Other processes listed, such as filtration, precipitation, and evaporation, do not specifically represent what occurs in the stabilization tank. Filtration typically happens in later stages of treatment to physically remove suspended solids, precipitation involves chemical reactions to separate solids from liquids, and evaporation is more relevant to water treatment processes concerning water recovery rather than biological treatment. Thus, the emphasis on absorption in the stabilization tank highlights its critical function in biological wastewater treatment.