Basic Wastewater Operator Practice Exam 2025 - Free Wastewater Operator Practice Questions and Study Guide

The primary treatment of wastewater focuses on removing larger solids from the water before it undergoes further treatment. This is primarily achieved through screening and sedimentation.

Screening involves the physical removal of large debris such as sticks, leaves, and plastic materials from the wastewater. This process prevents damage to subsequent treatment equipment and ensures operational efficiency.

Once the larger particles are screened out, sedimentation takes place. During sedimentation, the wastewater is held in a still environment allowing heavier solids to settle to the bottom as sludge, while lighter materials remain on the surface or in suspension. The settled sludge can then be removed, effectively reducing the total suspended solids in the wastewater.

This combined approach is crucial for preparing the influent for secondary treatment, where biological processes further purify the water. Other options listed, while important for the overall treatment process, do not specifically form the foundation of primary wastewater treatment.