PARAMETER DETERMINATION AND MODEL-FITTING - 2 APPROACHES FOR MODELINGPROCESSES IN WASTE-WATER TREATMENT PLANTS

This study shows results from four lab-scale wastewater treatment plan ts, which were installed behind the grit chamber of a municipal wastew ater treatment plant. The lab-scale plants were fed with original wast ewater, diluted with water from the final clarifier to give a constant concentration of 300 mg/l GOD. The activated sludges were adapted to different sludge ages from 1.88 to 24.0 days. The steady-state behavio ur was measured along with the decay rate, the yield coefficient, the oxygen demand, the C- and N-balance and the DNA of biomass X(BH). The steady-state equations of Marais and Ekama were used to calculate the masses of active biomass, endogenous residue and inert VSS in the reac tors. Measured parameter values were different far all sludge ages. Th ey gave similar values for inert particulate VSS (Xi) of 7 to 9%. Para meter values of the IAWQ-Model No.1 together with Xi-fitting could als o be used to solve the equations, but in this case different Xi values for the different reactors had to be used for the same wastewater. Co pyright (C) 1996 IAWQ.