纳米Fe_(2)O_(3)强化MBF生物巢脱氮的机制

Augmentation of nitrogen removal by MBF bio-nests supplemented with nano-Fe_(2)O_(3)

针对我国市政污水C/N比偏低的问题,本研究旨在探讨纳米氧化铁在MBF生物巢反应器中对低C/N比市政污水处理的强化脱氮效果及其机理。将纳米氧化铁添加到MBF生物巢反应器中,处理实际低C/N比市政污水,通过监测脱氮效率和碳源利用情况,结合微生物群落结构和功能基因表达量的分析,评价其处理效果。结果表明,纳米氧化铁的加入可显著提高反应器的脱氮效率,脱氮率提升了58%。微生物群落结构分析结果表明,纳米氧化铁影响了特定脱氮微生物的相对丰度。功能基因表达量分析结果表明,纳米氧化铁下调了微生物外膜上电子转移蛋白的表达,减少了种间电子传递,从而提高了胞内电子的有效利用率。以上结果表明,纳米氧化铁通过调节微生物群落结构和功能基因表达,可提高碳源的利用效率,进而实现对低C/N比市政污水的有效脱氮,可为市政污水处理提供技术途径参考。

Addressing the issue of low C/N ratio in municipal wastewater in China,this study aims to investigate the enhanced nitrogen removal efficacy and its mechanism of nano-iron oxide in an MBF bio-nest reactor treating municipal wastewater with low C/N ratio.As nano-iron oxide was added to the MBF bio-nest treating actual municipal wastewater with low C/N ratio,the nitrogen removal efficiency and carbon source utilization were monitored,and the microbial community structure and functional gene expression levels were also analyzed,then the performance on treating wastewater with low C/N ratio was evaluated.The results showed that addition of nano-iron oxide significantly increased the nitrogen removal efficiency of the reactor by 58%.Microbial community structure analysis revealed that nano-iron oxide affected the relative abundance of specific nitrogen-removing microorganisms.Functional gene expression analysis found that nano-iron oxide downregulated the expression of electron transfer proteins on the outer membrane of microorganisms,reducing interspecies electron transfer and thereby enhancing the effective utilization of electrons within the cells.Above results indicated that nano-iron oxide increased the efficiency of carbon source utilization and effectively removed nitrogen from municipal wastewater with low C/N ratio through regulating microbial community structure and functional gene expression.This provides a new technical approach for municipal wastewater treatment.