Gomez, VillegasDavid, JuanFruteau de Laclos, HélèneDovat, JulienMembrez, YvesHolliger, Christof2011-01-052011-01-052011-01-05201110.2166/wst.2011.430https://infoscience.epfl.ch/handle/20.500.14299/62654WOS:000291184100026A process based on partial nitrification and recirculation into the anaerobic digester was studied to remove nitrogen from digested manure and thus reduce enhanced gaseous ammonia emissions due to on-farm biogas production. An anaerobic reactor representing an anaerobic manure digester was fed with a nitrite solution and digested manure liquor. Nitrite was efficiently removed from the influent and ammonium formation was observed first. Ammonium was subsequently eliminated up to a maximum of 90% of the influent concentration indicating anaerobic ammonium oxidation activity. This activity however decreased again and was lost at the end of the 4 months operation period. In an 1.5-L aerobic CSTR that was fed with digested manure liquor, ammonium was efficiently removed from the influent. Nitrite and nitrate formation was observed but mass balances indicated significant N-removal. Accumulation of suspended solids was observed at the end of the experiment suggesting presence of oxygen-free environments. In a second test in a 15-L CSTR where suspended solids sedimentation could be avoided, low N-removal rates were observed in the absence of biofilm carrier elements whereas high N-removal rates were achieved in their presence. A simple one-stage process based on immobilized biomass could therefore be installed downstream of agricultural anaerobic digesters in order to mitigate undesirable gaseous ammonia emissionsammonia emissionsAnammoxbiogasdenitrificationpartial nitrificationAnaerobic Ammonium OxidationPiggery Waste-WaterAerobic DenitrificationBiological TreatmentAnammoxNitriteReactorOxidetext::journal::journal article::research article