School of Life Science, Nanjing University, Nanjing 210023, China.
Int J Environ Res Public Health. 2021 Mar 31;18(7):3633. doi: 10.3390/ijerph18073633.
Lab-scale simulated biofilm reactors, including aerated reactors disturbed by short-term aeration interruption (AE-D) and non-aerated reactors disturbed by short-term aeration (AN-D), were established to study the stable-state (SS) formation and recovery after disturbance for nitrogen transformation in terms of dissolved oxygen (DO), removal efficiency (RE) of NH-N and NO-N and activity of key nitrogen-cycle functional genes A and S (RNA level abundance, per ball). SS formation and recovery of DO were completed in 0.56-7.75 h after transition between aeration (Ae) and aeration stop (As). In terms of pollutant REs, new temporary SS formation required 30.7-52.3 h after Ae and As interruptions, and seven-day Ae/As interruptions required 5.0% to 115.5% longer recovery times compared to one-day interruptions in AE-D and AN-D systems. According to A activity, 60.8 h were required in AE-D systems to establish new temporary SS after As interruptions, and RNA A copies (copy number/microliter) decreased 88.5%, while 287.2 h were required in AN-D systems, and RNA A copies (copy number/microliter) increased 36.4 times. For S activity, 75.2-85.8 h were required to establish new SSs after Ae and As interruptions. The results suggested that new temporary SS formation and recovery in terms of DO, pollutant REs and A and S gene activities could be modelled by logistic functions. It is concluded that temporary SS formation and recovery after Ae and As interruptions occurred at asynchronous rates in terms of DO, pollutant REs and A and S gene activities. Because of DO fluctuations, the quantitative relationship between gene activity and pollutant RE remains a challenge.
建立了实验室规模的模拟生物膜反应器，包括受短期曝气中断 (AE-D) 干扰的曝气反应器和受短期曝气干扰的非曝气反应器 (AN-D)，以研究溶解氧 (DO) 方面的氮转化的稳定态 (SS) 形成和干扰后的恢复、NH-N 和 NO-N 的去除效率 (RE) 以及关键氮循环功能基因 A 和 S 的活性 (RNA 水平丰度，每个球)。在曝气 (Ae) 和曝气停止 (As) 之间的转变后 0.56-7.75 h 内完成了 DO 的 SS 形成和恢复。就污染物 RE 而言，在 Ae 和 As 中断后，新的临时 SS 形成需要 30.7-52.3 h，与 Ae-D 和 AN-D 系统中的一天中断相比，七天的 Ae/As 中断需要 5.0%到 115.5%更长的恢复时间。根据 A 活性，AE-D 系统在 As 中断后建立新的临时 SS 需要 60.8 h，RNA A 拷贝数 (拷贝数/微升) 减少了 88.5%，而在 AN-D 系统中需要 287.2 h，RNA A 拷贝数 (拷贝数/微升) 增加了 36.4 倍。对于 S 活性，在 Ae 和 As 中断后建立新的 SS 需要 75.2-85.8 h。结果表明，DO、污染物 RE 和 A 和 S 基因活性方面的新临时 SS 形成和恢复可以通过逻辑函数来模拟。结论是，在 DO、污染物 RE 和 A 和 S 基因活性方面，Ae 和 As 中断后的临时 SS 形成和恢复以不同步的速率发生。由于 DO 波动，基因活性与污染物 RE 之间的定量关系仍然是一个挑战。
