Effect of nano zero-valent iron addition on caproate fermentation in carboxylate chain elongation system

Xindi Fu; Rong Ye; Xi Jin; Wenjing Lu

doi:10.1016/j.scitotenv.2020.140664

Effect of nano zero-valent iron addition on caproate fermentation in carboxylate chain elongation system

Sci Total Environ. 2020 Nov 15:743:140664. doi: 10.1016/j.scitotenv.2020.140664. Epub 2020 Jul 2.

Authors

Xindi Fu¹, Rong Ye¹, Xi Jin¹, Wenjing Lu²

Affiliations

¹ School of Environment, Tsinghua University, Beijing 100084, China.
² School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: luwenjing@mail.tsinghua.edu.cn.

PMID: 32679493
DOI: 10.1016/j.scitotenv.2020.140664

Abstract

Carboxylate chain elongation is a burgeoning research area for producing added value bio-products from organic fraction of municipal solid waste. Effect of nano zero-valent iron (NZVI) on chain elongation and its possible mechanism was investigated. Highest caproate concentration, 28.0 mmol·L^-1 was achieved with 2 g·L^-1 NZVI amendment, which is about 16.7% higher than the control. Promoted ethanol utilization was considered as the main reason for the increment of caproate production and hydrogen generation. Electron balance analysis shows that NZVI did not improve the total electron recovery efficiency but favoured the electron flow toward longer carboxylate chain product, i.e. caproate. Finally, full-length 16s rRNA sequencing of bacterial community showed NZVI reshaped the bacterial community by exerting reduction selectivity. And Oscillibacter and Clostridium could be the potential functional species for carboxylate chain elongation.

Keywords: Carboxylate; Chain elongation; Nano zero-valent iron.

MeSH terms

Caproates*
Ethanol
Fermentation
Iron*
RNA, Ribosomal, 16S

Substances

Caproates
RNA, Ribosomal, 16S
Ethanol
Iron