Long-term effects of acetylene on denitrifying N2O production: Biomass performance and microbial community. (August 2021)

• Record Type: Journal Article
• Authors: Shen, Xun-yu; Zhuge, Yang-yang; Liu, Yong-di; Shapleigh, James P.; Li, Wei
• Is Part Of: Journal of water process engineering. Volume 42(2021)
• Publication Date: 2021-08
• Subjects: N2O recovery -- Denitrification -- Acetylene -- Denitrifying community -- Metagenomics; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2021.102137
• Languages: English
• ISSNs: 2214-7144

Abstract

Graphical abstract: Highlights: Long-term exposure to acetylene resulted in high denitrifying N2 O production. Long-term exposure to acetylene didn't reduce the nosZ occurrence in the community. Bacteria harboring nosZⅡ gene became dominated by long-term exposure to acetylene. N2 O reduction in denitrification could be restored rapidly upon removal of acetylene. Abstract: Maximizing production and use of N2 O produced by the process of denitrification has emerged as a promising concept for energy recovery from nitrogen. Acetylene is well known as an inhibitor of N2 O reductase activity, however, to date, few studies have utilized long-term cultivation with acetylene to achieve denitrifying N2 O recovery. This work assessed the performance of N2 O production and shifts in the denitrifying community in response to long-term exposure of acetylene during nitrite denitrification. Batch tests showed that long-term exposure to acetylene at high concentrations (volume fraction >40 %) resulted in high N2 O accumulation, up to 98.6 %. High-throughput 16S rRNA gene analysis suggested that Saprospiraceae dominated the microbial community at the end of the cultivation period with its abundance increasing from the initial 3.2% to 42.2%. Metagenomic analysis revealed that after the long-term cultivation under high level acetylene, the relative abundance of nosZ in the community did not change significantly. Instead, the nosZⅡ -harboring bacteria became dominant. Batch tests in series demonstrated that N2 O reduction could be restored rapidly upon removal of acetylene. This study describes an effective method for high yield production of N2 O during nitrite denitrification that can be used to enhance energy recovery and improves our understanding of the long-term effect of acetylene on the denitrifying community.