Basic Wastewater Operator Practice Exam

The function of a clarifier in wastewater treatment is to allow the settling of solids for improved effluent clarity. In the treatment process, wastewater often contains a mixture of solid particles and liquids. The clarifier operates by slowing down the flow of wastewater, which reduces the turbulence that keeps solids suspended. As a result, heavier solids settle to the bottom of the clarifier, forming a sludge layer, while the clearer liquid, known as supernatant, remains at the top. This separation process is crucial for enhancing the quality of the effluent, as it effectively removes particulates and reduces the overall load on subsequent treatment steps. The clarified supernatant can then be further treated or released into the environment, contributing to cleaner waterways.

Other methods, such as heating, the introduction of chemicals, or aeration, serve different purposes in wastewater treatment but do not describe the primary function of the clarifier. Heating would address temperature adjustments, chemical introduction would involve reaction and treatment processes, and aeration is focused on enhancing oxygen transfer in biological treatment phases.