绿色电子供给和细胞代谢调控型反硝化研究

Denitrification research based on green electron supply and cell metabolism regulation

作为氮循环的关键环节,微生物反硝化在去除水环境中硝酸盐污染、实现氮元素返回大气和维持氮平衡方面具有重要作用。目前,异养反硝化是生物脱氮的主流工艺,但在处理低碳氮比废水过程中往往需要额外投加乙酸等化学碳源,以获得足够的电子供体,从而实现高效脱氮。近年来,国内外学者围绕光生电子、短链气态烷烃等新型绿色电子供体的供给以及促进电子供体利用的代谢调控方法开展了大量研究。首先,归纳了光电子驱动反硝化的光敏剂种类、主导功能微生物、光敏剂-微生物复合方式以及光电反硝化的应用现状;然后,阐述了以甲烷、丙烷等短链烷烃为碳源进行反硝化的微生物代谢途径,介绍了餐厨垃圾等有机废弃物的碳源化性能,分析了微生物内碳源的形成机制和利用特性;最后,探讨了通过提升微生物对电子的利用效率来促进反硝化的作用原理,以期拓展对高效生物脱氮机制的理解,并提出了绿色电子高效供给和微生物细胞内电子分配调控等未来探索方向,旨在为反硝化脱氮技术的发展提供借鉴与参考。

As a key link in the nitrogen cycle,microbial denitrification plays an important role in removing nitrate pollution from the water environment,realizing the return of nitrogen to the atmosphere,and maintaining nitrogen balance.Heterotrophic denitrification is the mainstream process of biological nitrogen removal at present.In the process of treating wastewater with a low carbon-to-nitrogen ratio,chemical carbon sources such as acetic acid are often added to obtain enough electron donors to achieve efficient nitrate removal.In recent years,researchers have focused on the development of novel electron donors such as photoelectrons,short-chain gaseous alkanes,and metabolism regulation methods to promote the utilization of electron donors.Firstly,the types of photosensitizers,the dominant functional microorganisms,the photosensitizer-microbe complex in the process of photoelectron-driven denitrification,and the application status of phototrophic denitrification are systematically reviewed.Then,the microbial metabolic pathway of denitrification using methane,propane,and other short-chain alkanes as carbon sources is described,the performance of kitchen waste and other organic wastes as carbon source is introduced,and the formation mechanism and utilization characteristics of microbial carbon sources are also analyzed.Finally,the mechanisms of promoting denitrification by improving electron utilization efficiency of microorganisms are discussed,in order to expand the understanding of efficient biological nitrogen removal mechanisms.The future exploration direction,such as the efficient supply of green electrons and the regulation of intracellular electron distribution,are proposed,aiming to provide reference for the development of biological denitrification technology.