to Example 9.1, that the use of a single filter produces a plant efficiency of about 75%, with very high hydraulic and BOD loading rates. To reduce the loading rates and increase plant efficiency, the engineer decides to add an identical filter in parallel to the first one. The direct recirculation ratio is maintained at 2.0. Wastewater temperature is 20°C. Calculate the new hydraulic loading rate, organic loading rate, effluent BOD5 concentration, and overall plant efficiency. Is the new design better than the old one?