Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland.
Water Sci Technol. 2011;63(9):1991-6. doi: 10.2166/wst.2011.430.
A 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-month operation period. In a 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 emissions.
研究了一种基于部分硝化和回流到厌氧消化器的工艺，以去除消化粪便中的氮，从而减少由于农场沼气生产而导致的增强的气态氨排放。一个代表厌氧粪便消化器的厌氧反应器用亚硝酸盐溶液和消化粪便液体进料。亚硝酸盐从进水口有效地去除，首先观察到氨的形成。随后，氨的去除率高达进水浓度的 90%，表明存在厌氧氨氧化活性。然而，这种活性再次下降，并在 4 个月的运行期结束时丧失。在一个 1.5 L 的有氧 CSTR 中，用消化粪便液体进料，氨从进水口有效地去除。观察到亚硝酸盐和硝酸盐的形成，但质量平衡表明有显著的氮去除。在实验结束时观察到悬浮固体的积累，表明存在无氧环境。在第二个 15 L CSTR 的测试中，由于可以避免悬浮固体沉淀，在没有生物膜载体的情况下，氮去除率很低，而在存在生物膜载体的情况下，氮去除率很高。因此，可以在农业厌氧消化器的下游安装基于固定化生物量的简单单级工艺，以减轻不良的气态氨排放。
