State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China; Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia.
Water Res. 2024 Sep 15;262:122078. doi: 10.1016/j.watres.2024.122078. Epub 2024 Jul 10.
How to intensify the ammonia oxidation rate (AOR) is still a bottleneck impeding the technology development for the innovative acidic partial nitritation because the eosinophilic ammonia-oxidizing bacteria (AOB), such as Nitrosoglobus or Nitrosospira, were inhibited by the high-level free nitrous acid (FNA) accumulation in acidic environments. In this study, an innovative approach of dynamic acidic pH regulation control strategy was proposed to realize high-rate acidic partial nitritation driven by common AOB genus Nitrosomonas. The acidic partial nitrification process was carried out in a laboratory-scale sequencing batch moving bed biofilm reactor (SBMBBR) for long-term (700 days) to track the effect of dynamic acidic pH on nitrifying bacterial activity. The results indicated that the influent NH-N concentration was about 100 mg/L, the nitrite accumulation ratio was exceeding 90%, and the maximum AOR can reach 14.5 ± 2.6 mg N Lh. Although the half-saturation inhibition constant of NOB (K) reached 0.37 ± 0.10 mg HNON/L and showed extreme adaptability in FNA, the inactivation effect of FNA (6.1 mg HNON/L) for NOB was much greater than that of AOB, with inactivation rates of 0.61 ± 0.08 h and 0.06 ± 0.01 h, respectively. The effluent pH was gradually reduced to 4.5 by ammonia oxidation process and the periodic FNA concentration reached 6.5 mg HNON/L to inactivate nitrite-oxidizing bacteria (NOB) without negatively affecting Nitrosomonas during long-term operation. This result provides new insights for the future implementation of high-rate stabilized acidic partial nitritation by Nitrosomonas.
如何提高氨氧化速率（AOR）仍然是阻碍创新型酸性亚硝化技术发展的瓶颈，因为嗜酸氨氧化菌（AOB），如亚硝化单胞菌或硝化螺旋菌，会被酸性环境中高水平的游离亚硝酸（FNA）积累所抑制。在本研究中，提出了一种创新的动态酸性 pH 调控控制策略，以实现由普通 AOB 属亚硝化单胞菌驱动的高速酸性亚硝化。在实验室规模的序批式移动床生物膜反应器（SBMBBR）中进行了酸性部分硝化过程，进行了长期（700 天）的实验以跟踪动态酸性 pH 对硝化细菌活性的影响。结果表明，进水 NH-N 浓度约为 100 mg/L，亚硝酸盐积累率超过 90%，最大 AOR 可达 14.5 ± 2.6 mg N Lh。尽管亚硝酸盐氧化菌（NOB）的半饱和抑制常数（K）达到 0.37 ± 0.10 mg HNON/L，并且在 FNA 中表现出极端的适应性，但 FNA（6.1 mg HNON/L）对 NOB 的失活效果远大于对 AOB 的失活效果，失活率分别为 0.61 ± 0.08 h 和 0.06 ± 0.01 h。氨氧化过程将出水 pH 逐渐降低至 4.5，并且周期性的 FNA 浓度达到 6.5 mg HNON/L，在长期运行过程中不会对亚硝化单胞菌产生负面影响的情况下，有效地灭活亚硝酸氧化菌（NOB）。该结果为未来通过亚硝化单胞菌实现高速稳定的酸性亚硝化提供了新的见解。
