Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Stoneczna St. 45G, 10-709 Olsztyn, Poland.
J Environ Sci (China). 2012;24(6):990-8. doi: 10.1016/s1001-0742(11)60867-x.
The impact of the organic carbon to nitrogen ratio (chemical oxygen demand (COD)/N) in wastewater and dissolved oxygen (DO) concentration on carbon and nitrogen removal efficiency, and total bacteria and ammonia-oxidizing bacteria (AOB) communities in activated sludge in constantly aerated sequencing batch reactors (SBRs) was determined. At DO of 0.5 and 1.5 mg O2/L during the aeration phase, the efficiency of ammonia oxidation exceeded 90%, with nitrates as the main product. Nitrification and denitrification achieved under the same operating conditions suggested the simultaneous course of these processes. The most effective nitrogen elimination (above 50%) was obtained at the COD/N ratio of 6.8 and DO of 0.5 mg O2/L. Total bacterial diversity was similar in all experimental series, however, for both COD/N ratios of 6.8 and 0.7, higher values were observed at DO of 0.5 mg O2/L. The diversity and abundance of AOB were higher in the reactors with the COD/N ratio of 0.7 in comparison with the reactors with the COD/N of 6.8. For both COD/N ratios applied, the AOB population was not affected by oxygen concentration. Amplicons with sequences indicating membership of the genus Nitrosospira were the determinants of variable technological conditions.
在持续曝气的序批式反应器（SBR）中，测定了废水中有机碳与氮的比例（化学需氧量（COD）/N）和溶解氧（DO）浓度对活性污泥中碳和氮去除效率以及总细菌和氨氧化菌（AOB）群落的影响。在曝气阶段 DO 为 0.5 和 1.5 mg O2/L 时，氨氧化效率超过 90%，主要产物为硝酸盐。在相同操作条件下进行的硝化和反硝化表明这些过程同时发生。在 COD/N 比为 6.8 和 DO 为 0.5 mg O2/L 时，获得了最高的有效氮去除率（超过 50%）。在所有实验系列中，总细菌多样性相似，但在 COD/N 比为 6.8 和 0.7 时，在 DO 为 0.5 mg O2/L 时观察到更高的值。与 COD/N 比为 6.8 的反应器相比，在 COD/N 比为 0.7 的反应器中，AOB 的多样性和丰度更高。对于应用的两种 COD/N 比，AOB 种群不受氧气浓度的影响。指示 Nitrosospira 属成员身份的扩增子是可变技术条件的决定因素。
