California Wastewater Treatment Operator Practice Exam 2025 - Free Wastewater Treatment Operator Practice Questions and Study Guide

The statement that the three main parts of trickling filters are media, distribution system, and underdrain is indeed correct. These components work together to facilitate the treatment process effectively.

The media is primarily responsible for providing surface area where microorganisms can attach and grow to decompose organic material present in the wastewater. The distribution system evenly disperses wastewater over the media, ensuring that all parts come into contact with it. The underdrain collects the effluent once it has moved through the media, allowing for proper drainage and further treatment processes. This triad of components is essential for the efficient operation of trickling filters, contributing to their ability to biologically treat wastewater.

The other options, while related to the operation of trickling filters, do not accurately encompass the primary structural design and mechanism of action of these systems.