Deammonification means a cost-effective and maximum shortening of the reaction path in
nitrogen elimination.
In the conventional processes (
nitrification/
denitrification) the
ammonium is completely converted into
nitrite and then into
nitrate. This is followed by denitrification of the nitrate with the availability of carbon in the elemental
nitrogen.
Alternatively, in deammonification, the
EssDe® process, the reaction path is shortened to the maximum. The ammonium is incompletely oxidized to nitrite (only in 50%). Nitrite is no longer converted into nitrate. The rest of the ammonium together with the nitrite formed are reduced directly to nitrogen gas by specialized bacteria, the
Planctomycetes.
Shown here as simplified equation: NH4
+ + NO2
→ N2 + 2 H2O
The incomplete
nitritation of the ammonium and direct conversion to elemental nitrogen results in an energy saving of around 60%. Since the process is autotrophic, no carbon source is required and the excess sludge is correspondingly low. This means that the operating costs are significantly lower compared to conventional processes. Another advantage of nitrogen elimination by the autotrophic organisms in deammonification is the fixation of carbon dioxide (0.4 t CO
2/t N), whereas large amounts of carbon dioxide are produced in the other biological processes (> 4.7 t CO
2/t N).
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