Question

In wastewater treatment, dimension the following pre-treatment unit for a wastewater treatment plant receiving a dry weather flow (dwf) of 18,000 m3/day. Assume that flow doubles during rain. A bar screen is used to remove the coarse waste. The rain water flow velocity in the screen channel (v) is 0.5 m/s and the flow-through velocity of the clean screen (V) is 0.9 m/s. What is the required open screen area (m2) for reaching this screen velocity during treatment of the rain weather flow?

Answer 1

9,000 m2

Answer 2

0.46