Chapter 4: Activated Sludge Modelling - IqTMA-UVa

Processes for Biological NitrogenRemoval: Preanoxic Treatment5. Calculate the amount (kg/d) of nitrate fed to the anoxic tank. The designin based on the assumption that all the nitrate fed is reduced.6. Select an anoxic tank HRT (typically 2.5 h) V Anox(Based on Q o)7. Calculate de F/M bbased on the biomass calculated in the nitrificationdesign (X b)8. Estimate SDNR based on the F/M band rbCOD/bCOD ratios (Fig 8-23 inMetcalf & Eddy, 2003). Correct for T and IR9. Using the SDNR adjand the V Anoxselected in step 6 calculate the potentialNO 3-removed. Compared with the amount calculated in step 510. Repeat the procedure from step 6 by selecting a higher or lower V Anox.11. Check alkalinity Balance:[Alkalinity to maintain pH at 7 (typically 80 mgCaCO 3 )] = [ Influent Alk] + [Alkproduced (typically 3.57 g CaCO 3 /g N-NO - 3 reduced)] – [Effluent Alk] – [Alkconsumed (typically 7.14 g CaCO 3 /g N-NH + 4 oxidized)]50