In this study, a functionally stable insoluble Cu/Fe nanoparticles (Cu/Fe NPs) were synthesized and applied denitrification with different contaminants. The results showed that 50 mg/L Cu/Fe NPs increased NO3–-N reduction rate up to 14.3 mg/(L·h) about 3 folds compared with the control system (4.7 mg/(L·h)), and Cu/Fe NPs exhibited excellent restorative effects on NO3–-N reduction under the stress of Cd2+, Nitrovin and Methyl Orange. Meanwhile, electrochemical analyses, enzyme activities, and related genes abundance together showed that pilus, cytochrome c and flavin mononucleotide were electron carriers to tandem extracellular and intracellular, increasing electron flux acting on NO3–-N in the respiratory chain. Metagenomic sequencing showed that microbial metabolic activity, electroactive bacteria (EAB) abundance with bi-directional electron transfer and Cu/Fe-compatible bacterial abundance were increased. Furthermore, denitrification performance was maintained by establishing C-EAB-Cu/Fe NPs cycling network. This study provided insights and applications for expanding the use of insoluble mediators in denitrification systems.

中文翻译：

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具有串联细胞内和细胞外电子能力的非晶状 Cu/Fe 纳米颗粒，用于增强反硝化性能和回收共污染物抑制反硝化作用


在本研究中，合成了一种功能稳定的不溶性 Cu/Fe 纳米颗粒 （Cu/Fe NPs），并对不同的污染物进行了反硝化反应。结果表明，50 mg/L Cu/Fe NPs将NO3–-N还原速率提高至14.3 mg/（L·h），比对照系统（4.7 mg/（L·h））提高约3倍，Cu/Fe NPs在Cd2+、硝基文和甲基橙胁迫下对NO3–-N还原表现出优异的修复效果。同时，电化学分析、酶活性和相关基因丰度共同表明，菌毛、细胞色素 c 和黄素单核苷酸是串联细胞外和细胞内的电子载体，增加了作用于呼吸链中 NO3–-N 的电子通量。宏基因组测序显示，微生物代谢活性、双向电子转移的电活性细菌 （EAB） 丰度和 Cu/Fe 相容细菌丰度增加。此外，通过建立 C-EAB-Cu/Fe NPs 循环网络，保持了脱硝性能。本研究为扩大不溶性介质在反硝化系统中的使用提供了见解和应用。