What describes solid remains in water, often used in mechanical processes, which are approximately 8 mm in size?

The description provided in the question refers to the solid remains in water that are around 8 mm in size and used in mechanical processes, which aligns with the function of a hammermill device. A hammermill is a type of grinding machine that applies mechanical force to break down solid materials, such as solids found in water waste, into finer particles.

These devices are commonly utilized in various industries, including wastewater treatment, to reduce the size of solids for easier handling, processing, or further treatment. The size mentioned (approximately 8 mm) indicates that the hammermill can effectively handle solids of that dimension, making it appropriate for processing in mechanical applications.

Other devices listed do not fulfill this specific description as precisely as the hammermill does. For instance, a comminutor also processes solids but is typically designed for different size ranges and variations in operation. A mesh screen is utilized for filtering rather than grinding or breaking down materials, and a barminutor device is not a standard term widely recognized in mechanical processing contexts. Thus, the hammermill stands out as the correct response based on its defined function and application in processing solid remains in water.