Modelling COD and N removal in the water and in the benthic biofilm for the River Wupper in Germany

Abstract

The River Wupper, a tributary of the River Rhine, is at several locations influenced by anthropogenous nitrogen input, hydraulic structures, and influents from other tributaries. These influences have an impact both on the water quality and on the hydrodynamic conditions. The model approaches used for this article are based on work of Rauch et al. and the River Water Quality Model No. 1; they allow the simulation of the nitrogen conversion in the River Wupper. They are compatible with the activated sludge models and can thus be used also for integrated approaches. The calibration and validation of the model was realized using actual data of the River Wupper over a length of 60 km with one dam, 10 weirs, three wastewater treatment plants and 11 tributaries. The model considers the nitrogen conversion and COD removal and has a strong focus on biofilm processes in the benthic zone. Additional information is given about the sedimentation processes, the physical oxygen input processes, biofilm detachment processes, molecular diffusion, the influence of the laminar border layer and the changing of COD fractions and biofilm densities.

On the effect of scaling conceptual model complexity on stochastic response for water quality modeling

“…For many problems, the choice of conceptual scale is unclear, with several equally suitable (or equally unsuitable, given issues of data availability and parameter identifiably) alternatives available (e.g. Wichern et al 2006). In this paper, the model surface response under uncertainty is examined for a water quality model with a scaleable conceptual model complexity.…”

Transformation and utilization of slowly biodegradable organic matters in biological sewage treatment of anaerobic anoxic oxic systems

“…However, differences in sewage composition cannot be described by COD. Currently, the Activated Sludge Models (ASMs) as suggested by the International Water Association are the most widely recognized methods for characterizing COD components (Ikumi et al, 2014;Wichern et al, 2006;Wu et al, 2016). The quantitative characterization of these components is required for the application of ASMs.…”