Digestate as Fertilizer

Glossary
Aerobic digestion: Biological degradation processes that occur in the presence of oxygen.
Examples are composting and nitrification.
Anaerobic digestion: Biological degradation processes that occur when oxygen is not present,
because the microorganisms involved do not require oxygen for their metabolism or can be
inhibited or killed by it. Examples are biogas production and denitrification.
Ammonia (NH 3
): Pungent smelling and toxic gas which is chemically balanced with ammonium
depending on pH value and temperature.
Ammonium (NH 4
): Mineralised nitrogen compound used as a fertilizer available for plants.
Ammonium sulphate solution is produced in an acid scrubber by binding NH 3
to sulfuric acid
and can be used as mineral fertilizer or mixed back into the liquid digestate.
Flocculants: Operating aids used to achieve higher solid separation during separation. This creates
an agglomeration of the particles contained in the digestate and thus improves the separation.
Nitrification and denitrification: Nitrification is the aerobic (aerated) conversion of NH 4
or NH 3
via
nitrite to nitrate. Denitrification is the anaerobic conversion of nitrate to atmospheric nitrogen (N 2
).
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