Weak magnetic field: A powerful strategy to enhance partial nitrification
Weak magnetic field: A powerful strategy to enhance partial nitrification
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弱磁场：增强部分硝化作用的有力策略
DOI：
10.1016/j.watres.2017.04.058
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发表时间：
2017-09-01
期刊：
影响因子：
12.8
通讯作者：
Gao, Baoyu
中科院分区：
文献类型：
--
作者：
Wang, Zhibin;Liu, Xiaolin;Gao, Baoyu
短程硝化-厌氧氨氧化工艺是一种很有前途的污水脱氮技术。本研究的目的是调查潜在的外部磁场，以加强PN过程中的短期和长期的实验室规模的实验。在短期间歇试验中，对不同强度的磁场（0、5、10、15、20和25 mT）进行了评价，发现5 mT磁场对PN聚生体中好氧氨氧化菌（AOB）的活性有较好的提高作用。采用5 mT磁场研究了磁场对PN聚生体的长期影响。结果表明，磁场对PN过程的积极影响也可以在所有的四个阶段得到证实。随着磁场强度的增加，细菌多样性降低。亚硝化单胞菌科的相对丰度从RCK的13.9%显著下降到R-5 mT的12.9%和R-25 mT的5.5%（p < 0.01）。基于KEGG数据库的功能基因预测表明，与无磁场和高磁场环境相比，在5 mT环境中与信号转导和细胞运动相关的功能基因表达量更高。5 mT磁场的存在并没有增加氨氧化细菌的丰度，但通过增加游离氨进入微生物细胞内部的速率而增加了氨氧化细菌的活性。根据本文提出的假设，外加磁场不能改变PN过程的终态。这些结果表明，弱磁场是一种简便的提高AOB活性的方法，对PN过程的快速启动是有效和可靠的。(C)2017爱思唯尔有限公司版权所有
Partial nitrification (PN) combined with anaerobic ammonium oxidation process has been recognized as a promising technology for the removal of nitrogenous contaminants from wastewater. This research aimed to investigate the potential of external magnetic field for enhancing the PN process in short and long term laboratory-scale experiments. Different strength magnetic fields (0, 5, 10, 15, 20 and 25 mT) were evaluated in short-term batch tests and 5 mT magnetic field was found to have better ability to increase the activities of aerobic ammonium oxidizing bacteria (AOB) of PN consortium. Long-term effect of magnetic field on PN consortium was studied with 5 mT magnetic field. The results demonstrated that the positive effect of magnetic field on PN process could also be testified at all of the four stages. Furthermore, a decrease of bacterial diversity was noted with the increase of magnetic field strength. Relative abundance of Nitrosomonadaceae decreased significantly (p < 0.01) from 13.9% in RCK to 12.9% in R-5mT and 5.5% in R-25mT. Functional genes forecast based on KEGG database indicated that the expressions of functional genes related to signal transduction and cell motility in 5 mT environment were higher expressed compared with no magnetic field addition and high magnetic field addition. The existence of 5 mT magnetic field didn't increase the abundance of AOB but increased the activity of AOB by increasing the rate of free ammonia into the interior of microbial cells. Addition of magnetic field couldn't change the final state of PN process according to the hypothesis proposed in this article. These findings indicated that the weak magnetic field was useful and reliable for the fast start-up of PN process since it was proved as a simple and convenient approach to enhance AOB activity. (C) 2017 Elsevier Ltd. All rights reserved.