Modeling of NOM-removal in drinking water biofilters

Abstract

The application of biofiltration is a hot topic in the drinking water treatment field, and the mathematical modeling of biofilters has received considerable attention. However, no practical model is available for designing the biofiltration process. The aim of this research is to develop a representative model which simulates NOM (natural organic matter) removal in water treatment biofilter. A steady-state model was applied. Monod-type substrate utilization was used and the external and internal mass transfer was neglected in this model. The model described the process of substrate biodegradation, bacterial attachment onto filter media and detachment of suspended bacteria. It simulated the NOM and biomass profiles in a biofilter as a function of filter depth and filtration velocity. The key biokinetic parameters k and Ks were estimated through a special experiment. The results of the model testing show that the model prediction agrees well with the experimental data. It is possible to adapt the model under various conditions by changing the parameters such as flow rate, bacteria and DOC concentration et al. Therefore, the model is an effective tool for designing and operation.