Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, NanJing, People's Republic of China, 210098.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, NanJing, People's Republic of China, 210098.
Sci Total Environ. 2019 Nov 1;689:1044-1053. doi: 10.1016/j.scitotenv.2019.06.488. Epub 2019 Jul 2.
In this work, the feasibility and performance of zero valent iron (ZVI) coupled anaerobic microorganisms in nitrogen removal under low organic carbon condition were investigated, through the comparison of mono-ZVI system and mono-cell system. Coupled system showed the highest total nitrogen (TN) removal efficiency of 67.85% with the addition of 15 g L iron shavings at pH 7.0, which was higher than 29.62% in the mono-ZVI system and 43.86% in the mono-cell system. Besides, the activities of nitrate reductase (NAR), nitrite reductase (NIR), nitric oxide reductase (NOR) and nitrous oxide reductase (NOR) were significantly improved at ZVI dosage of 15 g L and pH 7.0, which contributed to the higher TN removal efficiency in coupled system. The extent of sludge granulation was greater in the coupled system than mono-cell system, which benefited to the high operational performance and stability of coupled system. The promoted generation of extracellular polymeric substances (EPS) and formation of iron oxides in the coupled system also took advantages on nitrogen removal through adsorption. In addition, ZVI could largely enrich the functional species related to nitrogen removal in the system at phyla and genera level, which could be reasoned for the enhanced nitrogen removal efficiency. In conclusion, this study will improve the understandings of nitrogen removal in the coupled system and be useful to ensure the application of ZVI-supported biological process in the remediation of farmland drainage.
在这项工作中，通过比较单零价铁（ZVI）系统和单细胞系统，研究了零价铁（ZVI）与厌氧微生物在低有机碳条件下协同去除氮的可行性和性能。在 pH 值为 7.0 时，添加 15 g/L 铁粉的耦合系统的总氮（TN）去除效率最高，达到 67.85%，高于单 ZVI 系统的 29.62%和单细胞系统的 43.86%。此外，在 ZVI 用量为 15 g/L 和 pH 值为 7.0 时，硝酸盐还原酶（NAR）、亚硝酸盐还原酶（NIR）、一氧化氮还原酶（NOR）和氧化亚氮还原酶（NOR）的活性显著提高，这有助于提高耦合系统的 TN 去除效率。与单细胞系统相比，耦合系统中污泥颗粒化的程度更大，这有利于耦合系统的高运行性能和稳定性。在耦合系统中，细胞外聚合物（EPS）的产生和氧化铁的形成也得到了促进，这有利于通过吸附去除氮。此外，ZVI 可以在属和种水平上大量富集与氮去除相关的功能物种，这可以解释氮去除效率的提高。总之，本研究将提高对耦合系统中氮去除的认识，并有助于确保 ZVI 支持的生物过程在农田排水修复中的应用。
