Wastewater Treatment Operator Certification Practice Test

What is the most common type of grit collector?

1. Deflectors

2. Weirs

3. Chain driven scrapers called "flights"

4. Parshall flume

The correct answer is: Chain driven scrapers called "flights"

Chain driven scrapers, known as "flights," are the most common type of grit collector used in wastewater treatment. These systems are designed to remove heavy particles, such as sand and gravel, that settle out of the wastewater stream. The chain-driven mechanism allows for effective collection and transport of grit to a designated disposal or processing area. The operation of grit collectors using flights involves a continuous movement that can efficiently scour the bottom of the grit chamber, guiding the grit toward a collection point. This method is advantageous because it provides reliable and consistent grit removal, which is essential for protecting downstream equipment from abrasive wear and maintaining overall system efficiency. While deflectors and weirs can aid in the management of flow and separation processes, they are not primarily designed for grit collection. Similarly, a Parshall flume is a flow measurement device used in wastewater applications but does not serve the function of grit removal. Thus, the use of flights in grit collectors effectively addresses the need for maintaining operational integrity in wastewater treatment facilities.