What process follows after the grit chamber in sewage treatment?

After the grit chamber in sewage treatment, the process that follows is biological treatment. The grit chamber's purpose is to remove heavy materials such as sand, gravel, and other grit that can damage equipment in subsequent treatment stages. Once this preliminary treatment is complete, the sewage, now free of large particulate matter, moves to the biological treatment stage.

During biological treatment, microorganisms are utilized to break down organic matter present in the sewage. This process typically occurs in aeration tanks where air is introduced to provide oxygen, which supports the growth of bacteria that consume the organic impurities. This stage is crucial because it significantly reduces the biochemical oxygen demand (BOD) of the wastewater, making it safer for discharge or further treatment.

This step is fundamental in ensuring effective waste management and reducing pollution in receiving waters. Following biological treatment, further processes such as filtration, chemical treatment, and disinfection may occur, but they come after this critical step.