What does the term "clarification" refer to in wastewater treatment?

The term "clarification" in wastewater treatment specifically refers to the process of allowing solids to settle from liquid wastewater. During this process, the liquid wastewater is typically held in a basin, allowing time for heavier solid particles to settle to the bottom and form a sludge layer. This separation is crucial because it enhances the overall quality of the effluent by removing suspended solids and reducing the concentration of pollutants before further treatment processes. The clarified water, which floats above the settled solids, can then move on to additional treatment stages or be discharged, depending on the treatment facility's design and regulatory requirements.

The other choices relate to different processes in the treatment of wastewater. Chemical treatment involves the addition of chemicals to aid in the removal of contaminants, while biological treatment employs microorganisms to break down organic matter. Monitoring water temperature is important for overall system efficiency and effectiveness but does not specifically pertain to the clarification process.