Udert Kai M, Kind Elija, Teunissen Mieke, Jenni Sarina, Larsen Tove A
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.
Water Sci Technol. 2008;58(2):277-84. doi: 10.2166/wst.2008.389.
The combination of nitritation and autotrophic denitrification (anammox) in a single sequencing batch reactor (SBR) is an energy efficient process for nitrogen removal from high-strength ammonia wastewaters. So far, the process has been successfully applied to digester supernatant. However, the process could also be suitable to treat source-separated urine, which has very high ammonium and organic substrate concentrations (up to 8,200 gN/m3 and 10,000 gCOD/m3). In this study, reactor performance was tested for digester supernatant and diluted source-separated urine. Ammonium concentrations in both solutions were similar (between 611 and 642 gN/m3), thus reactor performance could be directly compared. Differences were mainly due to higher activity of heterotrophic bacteria in urine. Nitrogen removal was slightly higher for source-separated urine, because heterotrophic bacteria denitrified the nitrate that was produced by anammox bacteria. In spite of higher heterotrophic growth with source-separated urine, calculated sludge concentrations at steady state were higher with digester supernatant due to accumulation of inert particulate organic matter from the influent. Although the sludge concentrations are less problematic for source-separated urine, process instabilities are more likely, because lower pH values are reached and heterotrophic denitrification can cause sudden increases of nitrite concentrations and/or nitric oxide. Both compounds inhibit aerobic ammonium oxidizing bacteria, heterotrophic bacteria and, most importantly, anammox bacteria. Nitrite and nitric oxide production by heterotrophic denitrification must be better understood to optimize nitritation/anammox for source-separated urine.
在单个序批式反应器（SBR）中，亚硝化与自养反硝化（厌氧氨氧化）相结合是一种从高浓度氨废水中去除氮的节能工艺。到目前为止，该工艺已成功应用于消化池上清液。然而，该工艺也可能适用于处理源分离尿液，源分离尿液具有非常高的铵和有机底物浓度（高达8200 gN/m³和10000 gCOD/m³）。在本研究中，测试了反应器对消化池上清液和稀释的源分离尿液的性能。两种溶液中的铵浓度相似（在611至642 gN/m³之间），因此可以直接比较反应器性能。差异主要是由于尿液中异养细菌的活性较高。源分离尿液的氮去除率略高，因为异养细菌将厌氧氨氧化细菌产生的硝酸盐进行了反硝化。尽管源分离尿液的异养生长较高，但由于进水惰性颗粒有机物的积累，消化池上清液在稳态下计算出的污泥浓度更高。尽管污泥浓度对源分离尿液来说问题较小，但过程不稳定的可能性更大，因为会达到较低的pH值，异养反硝化会导致亚硝酸盐浓度和/或一氧化氮突然增加。这两种化合物都会抑制好氧氨氧化细菌、异养细菌，最重要的是抑制厌氧氨氧化细菌。为了优化源分离尿液的亚硝化/厌氧氨氧化工艺，必须更好地了解异养反硝化产生亚硝酸盐和一氧化氮的情况。
