California Wastewater Treatment Operator Practice Exam

What is the purpose of the grit channel?

1. Remove light organic waste

2. Remove heavy inorganic waste

3. Remove dissolved solids

4. Remove gases from the wastewater

The correct answer is: Remove heavy inorganic waste

The purpose of the grit channel is primarily to remove heavy inorganic waste, such as sand, gravel, and coarse particles that may be present in wastewater. These materials settle out from the water due to their heavier density compared to organic materials and dissolved solids. By efficiently removing these heavy inorganic contaminants, grit channels help protect downstream equipment such as pumps and clarifiers from abrasion and clogging, ensuring smoother operation of the wastewater treatment process. Light organic waste, dissolved solids, and gases do not belong in the grit channel’s primary function. Light organic materials tend to remain suspended in the water and are typically addressed in later stages of treatment. Dissolved solids are usually removed through advanced treatment processes, while gases are dealt with in separate systems focused on aeration or odor control.