What is the primary function of a grit chamber in a sewage treatment plant?

The primary function of a grit chamber in a sewage treatment plant is to remove heavy inorganic solids, such as sand, gravel, and other gritty materials that may be present in wastewater. This process is essential because these materials can cause significant damage to pumps and other mechanical equipment downstream if not removed early in the treatment process. By settling out these heavy particles in the grit chamber, the sewage treatment plant can operate more efficiently and safely, ensuring that the organic waste and other materials can be treated effectively in subsequent stages of the treatment process.

In this context, removing gravel aligns with the grit chamber's role, as gravel represents a category of grit that needs to be separated from the lighter organic materials for proper treatment.