Dimension an activated sludge tank, for a wastewater flow (Q) of 3000 m3/d, an inlet COD of 500 mg/L (So) and an outlet COD (S), of 50 mg/L. The SSLM (Mixed Liquor Suspended Solids) in the tank (X) are 3.5 kg/m3 and in the sludge (Xr) 20 kg/m3. The reactor will be designed with a cell retention time of 10 days (CRT), with a bacterial growth coefficient (Y) of 0.5 and a bacterial elimination coefficient (Kd) of 0.05 d-1.

Calculate:

Volume Hydraulic retention time mass load Purge Flow Recirculation flow Recirculation rate