Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
Shenzhen Pangu Environmental Protection Technology Co. Ltd, Shenzhen 518055, PR China.
Bioresour Technol. 2024 Oct;410:131237. doi: 10.1016/j.biortech.2024.131237. Epub 2024 Aug 8.
Zero-valent iron acts as an indirect electron donor, supplying ferrous iron for the nitrate-dependent ferrous oxidation (NDFO) process. The addition of activated carbon (AC) increased the specific NDFO activity in situ and ex situ by 0.4 mg-N/(d·g VSS) and 2.2 mg-N/(d·g VSS), respectively, due to the enrichment of NDFO bacteria. Furthermore, AC reduced the nitrous oxide emission potential of the sludge, a mechanism that metagenomic analysis suggests may act as a cellular energy storage strategy. During a 196-day experiment, a total nitrogen removal efficiency of 53.7 % was achieved, which may be attributed to the upregulation of key genes involved in iron oxidation and denitrification. Based on these findings, a model involving pilin, 'nanowires,' and a cyc2/?→/(FoxE→FoxY)/?→cymA/Complex III/?-mediated pathway for extracellular electron uptake was proposed. Overall, this work provides a feasible strategy for enhancing the nitrogen removal performance of the ZVI-NDFO process.
零价铁作为间接电子供体，为硝酸盐依赖型亚铁氧化（NDFO）过程提供亚铁。由于 NDFO 细菌的富集，活性炭（AC）的添加分别使原位和异位的特定 NDFO 活性增加了 0.4 mg-N/（d·g VSS）和 2.2 mg-N/（d·g VSS）。此外，AC 降低了污泥中氧化亚氮的排放潜力，宏基因组分析表明，这一机制可能是一种细胞能量储存策略。在 196 天的实验中，实现了 53.7%的总氮去除效率，这可能归因于与铁氧化和反硝化相关的关键基因的上调。基于这些发现，提出了一个涉及菌毛、“纳米线”以及细胞外电子摄取的 pilin、'nanowires'、cyc2/?→/(FoxE→FoxY)/?→cymA/Complex III/?介导途径的模型。总的来说，这项工作为增强 ZVI-NDFO 工艺的氮去除性能提供了一种可行的策略。
