Department of Municipal Engineering, Beijing University of Technology, Beijing, 100124, People's Republic of China.
Sci Rep. 2022 Jul 22;12(1):12588. doi: 10.1038/s41598-022-16566-9.
Anaerobic ammonia oxidizing (anammox) has already been recognized as an innovative and economical nitrogen removal technology. However, the effect of heavy metals on anammox bacteria in aquatic ecosystem remains largely unknown. Ni(II) is a common kind of heavy metals detected in industrial wastewater and municipal sewage treatment plants. Hence, the responses of the anammox process to Ni(II) were studied here. The results showed that anammox was the dominant reaction with Ni(II) concentrations no more than 25 mg/L. 1 mg/L of Ni(II) addition promoted nitrogen removal by anammox. The higher the Ni(II) concentrations and longer exposure time, the more inhibition for anammox bacteria was gotten. The IC of Ni(II) to anammox was determined as 83.86 mg/L by an exponential regression equation. The inhibition of Ni(II) on anammox activity was mainly attributed to intracellular accumulation Ni(II) inhibition to HDH activity. Two times increase of IC after 4 times circles of domestication suggests multiple intermittent domestication can increase the tolerance of anammox bacteria to Ni(II). EDTA washing can eliminate the inhibition of anammox activity by Ni(II) with Ni(II) addition no more than 25 mg/L.
厌氧氨氧化（anammox）已被认为是一种创新且经济的脱氮技术。然而，重金属对水生生态系统中厌氧氨氧化菌的影响在很大程度上尚不清楚。Ni(II)是工业废水中常见的重金属之一，也是城市污水处理厂中经常检测到的重金属。因此，本研究探讨了 Ni(II)对厌氧氨氧化过程的影响。结果表明，在 Ni(II)浓度不超过 25mg/L 的情况下，厌氧氨氧化是主要反应。添加 1mg/L 的 Ni(II)可促进厌氧氨氧化去除氮。Ni(II)浓度越高、暴露时间越长，对厌氧氨氧化菌的抑制作用越大。通过指数回归方程确定 Ni(II)对厌氧氨氧化的抑制常数（IC）为 83.86mg/L。Ni(II)对厌氧氨氧化活性的抑制主要归因于细胞内积累的 Ni(II)对 HDH 活性的抑制。经过 4 次驯化循环后，IC 增加了两倍，这表明多次间歇驯化可以提高厌氧氨氧化菌对 Ni(II)的耐受性。EDTA 洗涤可以消除 Ni(II)添加不超过 25mg/L 时对厌氧氨氧化活性的抑制作用。
