Comprehensive modelling of full-scale nitrifying and post-denitrifying biofilters

The Seine Aval (SAV) water resource recovery facility (WRRF), the largest WRRF in France (5 million PE), is being upgraded in order to tackle nowadays' wastewater treatment challenges such as urbanization and water resources protection. Compared with the treatment configuration before the upgrade, more intensive nutrient removal processes including membrane bioreactors (MBR) and biofilters have been introduced in the plant. The modernized plant should be evaluated in terms of treatment cost and environmental impacts as well as nutrient removal quality. Furthermore, delicate operation strategies are also required for the plant with large-scale use of intensive processes. With the development of engineering and modelling software, mathematical process models have become useful and low-cost tools for the performance evaluation and strategies development in the life cycle of a WRRF. Therefore, in parallel with the upgrade of the Seine Aval WRRF, SIAAP (Interdepartmental association for sewage disposal in the Paris agglomeration) launched a modelling project, which aims at developing a whole plant model for this facility after upgrade. The first step of the project focused on the 3-stage biofiltration process.