Nitrogen removal from landfill leachate via the nitrite route

The feasibility of removing nitrogen from mature landfill leachate using the nitrite route was investigated in a two-stage SBR system - (1º first stage, short-cut nitrification; second stage, denitrification via nitrite. With a volumetric exchange rate (n) of 0.3 d-1 and an oxygen concentration of between 1.2 and 1.3 mg/L, the nitrite accumulation ratio - (NO2-N)×100/(NOx-N)% - was between 32% and 37%. For the same hydraulic retention time, but lower oxygen concentration - between 0.8 and 0.9 mg/L - nitrite accumulation averaged 96%, indicating that ammonia was removed completely via the nit...