Nitrification front evolution in a biological aerated filter using expanded clay as a filter media

A pilot scale biological aerated filter (BAF) was built in order to test the ammonium removal from a
groundwater source intended for drinking water. Expanded clay granules were used as a filter media. In
order to study the conversion rates of various ammonium loads, a pollutant present in groundwater, the up-flow bioreactor was divided into three equal size sectors. The evolution of inorganic forms of nitrogen (NH4+, NO-2, NO-3) concentration fronts along the height of the filter media and the ammonium removal rates were determined.