Bioreduction of chromate in a syngas-based membrane biofilm reactor

Chenkai Niu, Xinyu Zhao, Danting Shi, Yifeng Ying, Mengxiong Wu, Chun Yu Lai, Jianhua Guo, Shihu Hu, Tao Liu

Research output: Journal article publicationJournal articleAcademic researchpeer-review


This study leveraged synthesis gas (syngas), a renewable resource attainable through the gasification of biowaste, to achieve efficient chromate removal from water. To enhance syngas transfer efficiency, a membrane biofilm reactor (MBfR) was employed. Long-term reactor operation showed a stable and high-level chromate removal efficiency > 95%, yielding harmless Cr(III) precipitates, as visualised by scanning electron microscopy and energy dispersive X-ray analysis. Corresponding to the short hydraulic retention time of 0.25 days, a high chromate removal rate of 80 µmol/L/d was attained. In addition to chromate reduction, in situ production of volatile fatty acids (VFAs) by gas fermentation was observed. Three sets of in situ batch tests and two groups of ex situ batch tests jointly unravelled the mechanisms, showing that biological chromate reduction was primarily driven by VFAs produced from in situ syngas fermentation, whereas hydrogen originally present in the syngas played a minor role. 16 S rRNA gene amplicon sequencing has confirmed the enrichment of syngas-fermenting bacteria (such as Sporomusa), who performed in situ gas fermentation leading to the synthesis of VFAs, and organics-utilising bacteria (such as Aquitalea), who utilised VFAs to drive chromate reduction. These findings, combined with batch assays, elucidate the pathways orchestrating synergistic interactions between fermentative microbial cohorts and chromate-reducing microorganisms. The findings facilitate the development of cost-effective strategies for groundwater and drinking water remediation and present an alternative application scenario for syngas.

Original languageEnglish
Article number134195
JournalJournal of Hazardous Materials
Publication statusPublished - 15 May 2024


  • Chromate reduction
  • Fermentation
  • Groundwater remediation
  • Membrane biofilm reactor (MBfR)
  • Syngas

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Bioreduction of chromate in a syngas-based membrane biofilm reactor'. Together they form a unique fingerprint.

Cite this