Full-scale application of the IAWQ ASM No. 2d model

In the framework of the EU-funded TTP-UPM project (Technology Transfer Project - Urban Pollution Management) the waste water treatment plant (WWTP) of Tielt was modelled with the recently issued IAWQ ASM No. 2d model. Up to 41% of the total COD load is originating from a textile industry. A measurement campaign was conducted during a period with industrial discharge and a period with only domestic sewage. The stop of the industrial discharge resulted in a highly dynamic response of the system. Based on an expert-approach the calibration was obtained changing only four parameters (anaerobic hydrolysis reduction factor η_fe, reduction factor for denitrification η_NO3, the decay rate of autotrophs b_AUT and the decay rate of the bio-P organism building blocks b_PAO, b_PHA, b_PP). Influent fractionation remains a critical step within the model calibration. A proven procedure to characterise the influent determinants by standard physical chemical analysis failed to assess the influent COD fractions when the textile waste water is discharged to the WWTP. Selected bench-scale experiments, instead, succeeded in providing the adequate influent characterisation accuracy. For characterising the readily biodegradable COD fraction respirometry is to be preferred.