Tennessee Wastewater Operator Practice Exam

What type of screen is designed to effectively remove hair and stringy material?

1. Manual bar screen

2. Perforated plate screen

3. Catenary screen

4. Continuous self-cleaning screen

The correct answer is: Perforated plate screen

The choice of a perforated plate screen is relevant when discussing the removal of hair and stringy materials due to its specific design and functionality. Perforated plate screens are engineered with holes or openings that allow wastewater to pass through while capturing larger solids, such as hair and stringy substances, which could clog or interfere with downstream processes. By utilizing a perforated plate design, the screen can maintain a balance between flow capacity and effective removal of unwanted debris. The uniform size of the perforations is crucial for catching materials that are typically found in wastewater, thus preventing them from proceeding through the treatment system where they might cause blockages or damage to equipment. While manual bar screens and continuous self-cleaning screens have their own applications, they may not be as effective for the precise task of removing very fine stringy materials. Manual bar screens require manual intervention, which can limit efficiency, and continuous self-cleaning screens can handle various solids but may not be specifically optimized for hair and similar debris. In summary, the perforated plate screen's design makes it an effective choice for the targeted removal of hair and stringy materials from wastewater, ensuring a more efficient treatment process.