Improvement of electron transfer efficiency during denitrification process by Fe-Pd/multi-walled carbon nanotubes: Possessed redox characteristics and secreted endogenous electron mediator

• Published in: The Science of the total environment Vol. 781; p. 146686
• Main Authors: Wang, Zeyu, Fu, Wangqin, Hu, Liyong, Zhao, Min, Guo, Tianjiao, Hrynsphan, Dzmitry, Tatsiana, Savitskaya, Chen, Jun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.08.2021
• Subjects: Alcaligenes; carbon nanotubes; deet; Denitrification; Electrochemistry; Electron transfer; electron transport chain; environment; Extracellular polymeric substance; Nanocomposites; nitrates; secretion; Denitrification; Electrochemistry; Electron transfer; Extracellular polymeric substance; Nanocomposites
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.146686

Nanomaterials which contacts microbial membranes for extracellular electron transfer, could establish a connection with the internal electron transfer chain of microorganisms. This characteristic could be employed to accelerate the denitrification process. In this study, the effect and mechanism of Pd-Fe/multi-walled carbon nanotubes (MWCNTs) on the extracellular electron transport behavior of Alcaligenes sp.TB was studied using electron transfer inhibitors and electrochemical methods. The main conclusions were as follows: the electron transfer site of Pd-Fe/MWCNTs was 266 mV, which was next to cytochrome c; the excellent electron exchange capacity of Pd-Fe/MMWCNTs (ΔEp = 734 mV) and the secretion of PN (33 mg/L) induced by Pd-Fe/MWCNTs both contributed to the occurrence of DEET process and promoted the electron transfer; the correlation between the electron mediator and the nitrate removal was analyzed were greater than 0.9731. [Display omitted] •The excellent electron exchange capacity of Pd-Fe/MMWCNTs (ΔEp = 734 mV) contributed to the occurrence of DEET process.•The site of Pd-Fe/MWCNTs (266 mV) were located next to cytochrome C in the DEET pathway.•The secretion of PN induced by Pd-Fe/MWCNTs also promoted the electron transfer during DEET process.