Enhancement effect of nanoscale zero-valent iron addition on microbial degradation of BDE-209 in contaminated mangrove sediment

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Ying Pan
  • Pui-Ying Leung
  • Yuan-Yue Li
  • Juan Chen
  • Nora F.Y. Tam

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number146702
Journal / PublicationScience of the Total Environment
Volume781
Online published25 Mar 2021
Publication statusPublished - 10 Aug 2021

Abstract

Chemical and biological methods have been employed to remedy polybrominated diphenyl ether contamination, but the removal of decabromodiphenyl ether (BDE-209) by either method still has limitations. The present study aims to evaluate the combined effect of nanoscale zero-valent iron (nZVI) (from 0.1 to 10%) reduction and microbial debromination on BDE-209 removal in mangrove sediments under an anaerobic condition. During the 12-months incubation, nZVI significantly enhanced BDE-209 removal, with 17.03% to 41.99% reduction in sterilized sediments. The reduction was even higher in non-sterilized sediments with living indigenous microorganisms, achieving 15.80%, 33.50%, 55.83% and 66.95% removal of BDE-209 at 0 (control without nZVI), 0.1%, 1% and 10% nZVI, respectively. In control sterilized sediments, no debromination was found, and debromination occurred according to spiked levels of nZVI, with BDE-153 being the dominant congener. The concentrations of debrominated congeners in non-sterilized sediments also increased with nZVI levels, but were significantly higher than the respective sterilized sediment. The relative proportions of different debrominated congeners in non-sterilized sediments depended on nZVI levels, with BDE-99 being the dominant congener in low nZVI amended sediments but shifted to BDE-153 under high nZVI. Higher concentrations of ferrous iron (Fe2+) were detected in both sterilized and non-sterilized sediments spiked with more nZVI, and their concentrations significantly correlated with BDE-209 removal. Growth of total bacteria in sediments with 1% and 10% nZVI was inhibited within first two months, but their numbers resumed to that in the control at the end of 12 months. The present study demonstrates the synergy between chemical and microbiological methods, and a combination of nZVI and indigenous microorganisms could be an efficient and feasible mean to remedy BDE-209 in contaminated sediments.

Research Area(s)

  • Mangrove, Microbial degradation, nZVI, PBDEs

Citation Format(s)

Enhancement effect of nanoscale zero-valent iron addition on microbial degradation of BDE-209 in contaminated mangrove sediment. / Pan, Ying; Leung, Pui-Ying; Li, Yuan-Yue; Chen, Juan; Kong, R.Y.C.; Tam, Nora F.Y.

In: Science of the Total Environment, Vol. 781, 146702, 10.08.2021.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review