MODEL-BASED CHARACTERIZATION OF HYDRAULIC, KINETIC AND INFLUENT PROPERTIES OF AN INDUSTRIAL WWTP

This paper illustrates the modelling of a full-scale industrial wastew ater treatment plant, First, the hydraulics of the plant were characte rised by a model-based interpretation of the results of a tracer test. The plant consists of three parallel reactors. The hydraulics of each reactor could be modelled by two tanks in series with non-equal volum e. These results were confirmed by calculation of the single pass resi dence time distribution. Also it was found that the influent flow and the recycle flow were not distributed equally to the three reactors,re sulting in different loading rates. Secondly, off-line respirometric e xperiments were performed to characterise the influent and to determin e the sludge kinetics. The same model structure could be applied to de scribe the influent characteristics and the biokinetics over a period of 1 year. It was found that all wastewaters could be fractionated int o three fractions and that one of the fractions was acetate-like. Conc entrations of the fractions changed significantly over the year. From on-line respirometric experiments the diurnal dynamics of the influent characteristics and the kinetics of the sludge were assessed. Analysi s of the respirograms showed that the wastewater composition and kinet ics of the sludge did not change significantly over;a short-term perio d of 40 hours. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.