Yoon So Yeon, Kim Min Ji, Kim Hye Won, Lim Seon Hwa, Choong Choe Earn, Oh Sang-Eun, Kim Jung Rae, Yoon Yeomin, Choi Jae Young, Choi Eun Ha, Jang Min
Department of Environmental Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea; Plasma Bioscience Research Center, Dasanjae 101, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea.
Department of Environmental Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea.
J Hazard Mater. 2023 Jun 15;452:131197. doi: 10.1016/j.jhazmat.2023.131197. Epub 2023 Mar 12.
The aim of this study was to investigate the effects of hydrophilic sulfur-modified nanoscale zero-valent iron (S-nZVI) as a biocatalyst for denitrification. We found that the denitrifying bacteria Cupriavidus necator (C. necator) promoted Fe corrosion during biocatalytic denitrification, reducing surface passivation and sulfur species leaching from S-nZVI. As a result, S-nZVI exhibited a higher synergistic factor (f = 2.43) for biocatalytic NO removal than nanoscale zero-valent iron (nZVI, f = 0.65) at an initial nitrate concentration of 25 mg L-N. Based on kinetic profiles, SO was the preferred electron acceptor over NO when using C. necator and S-nZVI for biocatalytic denitrification. Up-flow column experiments demonstrated that biocatalytic denitrification using S-nZVI achieved a total nitrogen removal capacity of up to 2004 mg L for 127 d. Notably, microbiome taxonomic profiling showed that the addition of S-nZVI to the groundwater promoted the growth of Geobacter, Desulfosporosinus, Streptomyces, and Simplicispira spp in the column experiments. Most of those microbes can reduce sulfate, promote denitrification, and match the batch kinetic profile obtained using C. necator. Our results not only discover the great potential of S-nZVI as a biocatalyst for enhancing denitrification via microbial activation but also provide a deep understanding of the complicated abiotic-biotic interaction.
本研究的目的是探究亲水性硫改性纳米零价铁（S-nZVI）作为生物催化剂用于反硝化的效果。我们发现，反硝化细菌脱氮副球菌（C. necator）在生物催化反硝化过程中促进了铁的腐蚀，减少了表面钝化和S-nZVI中硫物种的浸出。因此，在初始硝酸盐浓度为25 mg L-N时，S-nZVI在生物催化去除NO方面表现出比纳米零价铁（nZVI，f = 0.65）更高的协同因子（f = 2.43）。基于动力学曲线，当使用C. necator和S-nZVI进行生物催化反硝化时，SO是比NO更优先的电子受体。上流式柱实验表明，使用S-nZVI进行生物催化反硝化在127天内实现了高达2004 mg L的总氮去除能力。值得注意的是，微生物群落分类分析表明，在柱实验中向地下水中添加S-nZVI促进了地杆菌属、脱硫孢菌属、链霉菌属和简单螺旋菌属的生长。这些微生物中的大多数可以还原硫酸盐、促进反硝化，并与使用C. necator获得的批次动力学曲线相匹配。我们的结果不仅发现了S-nZVI作为通过微生物活化增强反硝化的生物催化剂的巨大潜力，还提供了对复杂的非生物-生物相互作用的深入理解。
