School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China.
School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China.
Water Res. 2022 May 15;215:118285. doi: 10.1016/j.watres.2022.118285. Epub 2022 Mar 12.
To date, the application of marine anammox bacteria (MAB) is still a challenge in saline wastewater treatment due to the low growth rate and high sensitivity. Herein, bioelectrochemical system with applied voltage was exerted for the first time to promote the activity of MAB for removing nitrogen from saline wastewater. At the optimal voltage of 1.5 V, the mean total nitrogen removal rate (TNRR) reached the maximum of 0.65 kg/m•d, which was 27.45% higher than that without applied voltage. Besides, applied voltage reduced the microbial diversity of MAB-based consortia, but the relative abundance of Candidatus Scalindua increased by 4.63% at 1.5 V compared with that without applied voltage. Also, proper applied voltage promoted the secretion of EPS and heme c, which resulted in the enhancement of MAB activity. Based on the remodified Logistic model analysis, the lag time of the nitrogen removal process was shortened by 0.72 h at the voltage of 1.5 V. Furthermore, it was found that higher voltage (> 2.0 V) had a negative effect on the MAB activity for low TNRR of 0.33 kg/m•d (2.5 V). However, TNRR increased back to 0.61 kg/m•d after removing the high applied voltage, which implied that the bioactivity was recoverable after being inhibited. These findings demonstrated that external electrical stimulation is an effective strategy to promote nitrogen removal and MAB activity for treating saline wastewater.
迄今为止，由于生长缓慢和高灵敏度，海洋厌氧氨氧化菌（MAB）在含盐废水处理中的应用仍然是一个挑战。在此，首次应用施加电压的生物电化学系统来促进 MAB 活性，以去除含盐废水中的氮。在 1.5 V 的最佳电压下，平均总氮去除率（TNRR）达到了 0.65 kg/m•d 的最大值，比没有施加电压时提高了 27.45%。此外，施加电压降低了基于 MAB 的菌群的微生物多样性，但与没有施加电压相比，在 1.5 V 时，Candidatus Scalindua 的相对丰度增加了 4.63%。此外，适当的施加电压促进了 EPS 和血红素 c 的分泌，从而提高了 MAB 的活性。基于修正的 Logistic 模型分析，在 1.5 V 的电压下，氮去除过程的滞后时间缩短了 0.72 h。此外，还发现较高的电压（>2.0 V）对 MAB 活性有负面影响，导致 TNRR 低至 0.33 kg/m•d（2.5 V）。然而，在去除高施加电压后，TNRR 增加到 0.61 kg/m•d，这表明生物活性在受到抑制后是可恢复的。这些发现表明，外部电刺激是促进氮去除和 MAB 活性以处理含盐废水的有效策略。
