Dynamic modeling of ammonia removal at low temperatures in drinking water rapid filters

Abstract

In drinking water production from surface water raw water quality is subject to major changes. In the case studied here, ammonia concentration varies between 0.05 and 4.2 mg/l. While at high temperatures effective ammonia removal is no problem at low temperatures ammonia breakthrough at the rapid filters can be observed. It was hypothesised that ammonia breakthrough mainly is a dynamic problem. A model was developed which takes into account the dynamic changes of attached nitrifiers due to growth, death and deposition of bacteria from the liquid phase. Backwashing was taken into account. The dynamic simulation showed that the model well describes the dynamic behaviour of the rapid filters with respect to ammonia removal over a period of one year.