Removal of ammonia from drinking water by biological nitrification. Common silica sand covered with manganese oxides is used as a filtration material. Manganese oxides layer serves as a rough support for the biofilm of nitrifying bacteria that are not thus removed from the packing during backwashing.
Ammonia is under controlled conditions biologically oxidized to nitrate.
The process was applied in several water treatment plants in central Bohemian region in full scale. Practicability of the two-step arrangement was also successfully verified in full scale. V. Janda and J. Rudovsky, Removal of ammonia from drinking water by biological nitrification.