Substrate inhibition and pH effect on denitritation with granular biomass

摘要

Undissociated HNO2 (up to 2 mg dm?3) was confirmed as substrate inhibitor for granular biomass from a denitritation upflow sludge bed reactor used for biological removal of nitrite. On the contrary, total nitrite nitrogen (N-NO2 up to 500 mg dm?3) and methanol (COD up to 2000 mg dm?3) were not proven to be inhibitors. pH also affected the denitritation efficiency (optimal pH was 5.9). Reduction of HNO2 concentration in the reactor by effluent recycling is recommended.