What device is used to retain or remove suspended or floating objects in wastewater?

The device used to retain or remove suspended or floating objects in wastewater is a screen. Screens serve as a primary mechanical treatment method in wastewater treatment plants. They consist of a network of bars or meshes that catch larger debris, such as leaves, plastics, and other solids, preventing them from entering subsequent treatment processes. This step is crucial, as it protects more delicate equipment and helps to ensure that the wastewater treatment process runs smoothly.

Screens come in various types, including coarse screens and fine screens, which differ in the size of the openings to target different sizes of particles. The primary function of screens is to enhance the efficiency of subsequent treatment processes, such as sedimentation and biological treatment, by reducing the load of suspended solids early in the treatment train.

While filters, scrubbers, and separators have their roles in various aspects of wastewater treatment, they do not specifically function as the initial barrier for suspended or floating objects in the same manner that screens do. Filters typically target finer particles and are used later in the treatment process, scrubbers often focus on gas treatment rather than solid removal, and separators are used for the phase separation of liquids and solids based on density, not for catching debris.