Nitrification of the liquid phase of digestate can help with the reduction of nitrogen losses

Abstract The effect of total ammonia nitrogen (TAN) transfer to nitrate via the nitrification process on the nitrogen loss during long-term storage of liquid phase of digestate (LPD) was verified. The treatments simulating summer (25 ± 2 °C) and winter (10 ± 0.5 °C) conditions were evaluated in addition to the influence of the stirring. The experiments proved that intensive nitrogen losses could be connected with the storage of raw LPD. Up to 87% of TAN was lost within 100 days and stirring led to a 96% increase in loss. Nitrogen loss observed during the storage of nitrified LPD did not exceed 6% even after 250 days where the stirring had no effect on the results. For raw and nitrified LPD, temperature had no significant influence on nitrogen loss.