微生物合成纳米钯强化反硝化选择性脱氮

作者：Bi Sijing; Chen Yuancai^*; Hu Yongyou

来源：Acta Scientiae Circumstantiae, 2022, 42(10): 202-207.

DOI：10.13671/j.hjkxxb.2022.0094

• biosynthetic nano-palladium（Bio-PdNPs）
• denitrification
• electron transfer
• nitrogen selectivity

In order to improve the nitrogen selectivity （Ns） of bio-denitrification，in this study，palladium nanoparticles （Bio-PdNPs） were biosynthesized by the denitrifying sludge，and the effects of different Bio-PdNPs loading（0，5 and 10 mg·L-1）were investigated. The results showed that the nitrate removal efficiency increased from 67.85% to 94.00%（C/N=7，5 h） at appropriate palladium loading （Bio-PdNPs-5），and the corresponding Ns increased from 77.30% to 97.46%. However，excessive Pd loading（Bio-PdNPs-10）inhibited denitrification，but the Ns was still up to 90.01%，which is of great significance for reducing N2O emissions. The mechanism analysis showed that Bio-PdNPs mediated denitrification was mainly attributed to butyric acid type and mixture fermentation，in which the hydrogen produced by fermentation could be rapidly captured by PdNPs and decomposed to form Pd［H］，eventually improved Ns. In addition，Bio-PdNPs also promoted electron transfer via stimulating the secreting cytochrome c，resulting in the electron transport system activity（ETSA）increasing from 570.37 μg·mg-1·h-1to 647.2 2 μg·mg-1·h-1 ? 2022 Science Press.