Process development for nitrogen removal of swine waste

This research aims to effectively remove nutrients in swine waste by a combined process of upflow anaerobic sludge blanket (UASB) and biofilm process. For effective removal of nutrients, both anaerobic and anoxic reactors were constructed consecutively within a single anaerobic/denitrification (SAD) reactor to which aerobic reactor for nitrification was connected. The total reactor was operated within range of 0.4 to 3.1 kg COD/m³/d of organics volumetric loading rate (VLR) and the removal rates of TCOD were 80 to 95%. Ammonia nitrogen was removed over 90% in VLR of less than 0.1 kg N/m³/d but removal rate was reduced to 70% in VLR of over 0.6 kg N/m³/d. However, complete denitrification was observed in all VLRs, which might be due to the maintenance of optimal temperature, sufficient inner carbon source, and use of NOx as an electron acceptor by anaerobic and anoxic microorganisms.