Investigation of the n-dynamics during composting under special consideration of N2-generation

The behaviour of N during composting was studied in 31 composting experiments. N-balances consi-dering N-compounds in the substrate and the emissions were generated. N2-formation could be detected in most experiments. Two different types of processes may be responsible. One probably occurred only at mesophilic temperatures and was only detectable under non-aerated conditions, the other took place at all relevant temperature zones and was measured also under aertion. N2 can be generated by denitrification under anoxic conditions. NO3- is a needed substrate, which may be formed via nitrification. Autotrophic nitrification occurs commonly under oxic and mesophilic conditions. Heterotrophic nitrification may occur under a wide range of conditions and is more important. Oxic-anoxic interfaces may be very important in any case