Biological nitrification
Nitrification is the biological process of converting ammonia into nitrate. For tertiary biological nitrification the autotrophic bacteria are using oxygen which is distributed evenly in the filter bed by means of a fine bubble aeration grid. Filtrate ammonia levels of < 2 mg/l ammonia-N are achieved consistently, even at water temperatures as low as 5 °C.
If you are interested in this topic, please have a look in our library, containing relevant white papers: for this topic we recommend the white paper with the title: “UK references with aerated continuous sand filters”.
