School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Sci Total Environ. 2022 Jan 15;804:149965. doi: 10.1016/j.scitotenv.2021.149965. Epub 2021 Aug 28.
Ammonium removal in wastewater treatment plants demands large quantities energy input, such as aeration for wastewater and the addition of organics for nitrate reduction. Anaerobic ammonium oxidation coupled to Fe(III) reduction, called Feammox process play a crucial role in natural nitrogen cycle, which has been rarely investigated in the field of wastewater treatment. Besides, Iron-reducing bacteria (FeRB) as function bacteria of Feammox could transfer electrons to iron oxide by oxidizing organics. The possibility of anaerobic ammonium removal coupled with organics should be investigated to assess the potential of Feammox process for conventional wastewater treatment. In this study, five Fe(III) compounds, FeO, FeO, Fe(OH), Citrate-Fe and pyrite were supplemented to investigate the effect of iron oxides on ammonium removal in serum bottles with working volume of 100 mL. It was found that ammonium removal efficiency of the FeO group was the highest. To simulate wastewater treatment process in sewage treatment plant, three Up-flow anaerobic sludge blanket reactors with volume of 250 mL adding FeO were applied with influent of ammonium and carbon sources. It was found that the organics significantly inhibited the ammonium removal by Feammox process. This was attributed to that carbon sources and ammonium could be used as electron donors for Fe(III) reduction. In addition, this nitrogen removal was also likely related with the iron cycle, i.e., Fe(III) reduction with ammonium oxidation and Fe(II) oxidation with nitrate/nitrite reduction. This study provides a promising alternative technology for anaerobic ammonium removal in wastewater treatment. Optimizing nitrogen removal and carbon sources applied in conventional wastewater plants are required in future.
在废水处理厂中去除氨需要大量的能量投入，例如为废水曝气和添加有机物进行硝酸盐还原。与 Fe(III)还原偶联的厌氧氨氧化，称为 Feammox 过程，在自然氮循环中起着至关重要的作用，但在废水处理领域很少被研究。此外，作为 Feammox 功能细菌的铁还原菌 (FeRB) 可以通过氧化有机物将电子转移到氧化铁上。应该研究厌氧氨去除与有机物的耦合，以评估 Feammox 过程用于传统废水处理的潜力。在这项研究中，添加了五种 Fe(III)化合物，FeO、Fe2O3、Fe(OH)3、柠檬酸盐-Fe 和黄铁矿，以研究氧化铁对血清瓶中氨去除的影响，血清瓶的工作体积为 100mL。结果发现，FeO 组的氨去除效率最高。为了模拟污水处理厂中的废水处理过程，应用了三个添加 FeO 的 250mL 上流式厌氧污泥床反应器，进水为氨和碳源。结果发现，有机物显著抑制了 Feammox 过程中的氨去除。这归因于碳源和氨可以作为 Fe(III)还原的电子供体。此外，这种氮去除也可能与铁循环有关，即氨氧化与 Fe(III)还原偶联，硝酸盐/亚硝酸盐还原与 Fe(II)氧化偶联。这项研究为废水处理中的厌氧氨去除提供了一种有前途的替代技术。在未来，需要优化传统废水厂中的氮去除和碳源应用。
