OPTIMIZATION OF WASTE-WATER TREATMENT PLANTS BY MEANS OF COMPUTER-MODELS

The objective of the work presented is to demonstrate how computer bas ed models can be used to improve the effluent quality from wastewater treatment plants by optimisation of the operation. The investigation w as carried out in connection with pilot plant investigations at Damhus aen Wastewater Treatment Plant in order to establish the design basis for upgrading the treatment plants in the city of Copenhagen. Calibrat ion of the model was done with thorough characterisation of the wastew ater and the activated sludge as the primary calibration tool. Special attention was paid to the nitrincation process, which by previous inv estigations was shown to be occasionally inhibited. Model constants fo r the nitrification process were determined from experiments. Default constants were used for nearly all other constants. The pilot plant wa s optimized with the calibrated model, Different operational strategie s for improvement of the denitrification process were tested. The deni trification process was operated relatively poorly at the time for the optimisation. The calibration showed that it was possible to calibrat e the model using the characterization of the wastewater and the activ ated sludge as the primary calibration tool. Further it was shown that the calibrated model could be used as a tool for optimising the opera tion of the pilot plant. The suggested operation correlated well with the practical realisable operation.