In wastewater treatment, which term describes a wall or plate used in open channels?

The term that describes a wall or plate used in open channels in wastewater treatment is "weir." A weir is specifically designed to measure flow rates or control water levels in various types of channels, including open channels like those found in treatment plants. It works by creating a controlled opening for water to flow over or through, allowing for accurate measurements of flow based on the height of the water above the weir.

Weirs are critical components in the hydraulic design of treatment systems, helping to maintain consistent flow rates and prevent overload in downstream processes. They also facilitate sedimentation by creating controlled flow conditions that allow for effective sediment settling and removal.

In contrast, barriers typically serve to block or divert flow, filters are used to remove particulates from liquids, and separators are designed to separate different phases of materials, such as oil and water. While these terms refer to important aspects of wastewater treatment, none specifically refer to the structures that function like weirs in open channel conditions.