Enhanced arsenic (III and V) removal in anoxic environments by hierarchically structured citrate/FeCO3 nanocomposites

Seon Yong Lee, Youngjae Kim, Bongsu Chang, Young Jae Lee

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

Novel citrate/FeCO3 nanocomposites (CF-NCs) were synthesized for effective arsenic (III and V) sorption with constant addition of Fe2+ into HCO3 solution in the presence of citrate. This paper is the first report on the formation of CF-NCs, and in this study we investigate the mechanisms of arsenic uptake by the sorbent under anoxic conditions through various solid-and liquid-phase spectroscopic methods, including X-ray absorption spectroscopy. In CF-NCs, citrate was found to be incorporated into the structure of siderite (up to 17.94%) through (Fe2+ citrate) complexes. The crystal morphology of rhombohedral siderite was changed into hierarchically nanostructured spherical aggregates composed of several sheet-like crystals, which improved the surface reactivity in the presence of sufficient citrate. Compared to pure siderite (15.2%), enhanced removal of As(III) in the range of 19.3% to 88.2% was observed, depending on the amount of incorporated citrate. The maximum sorption capacities of CF-NCs for As(III) and As(V) were 188.97 and 290.22 mg/g, respectively, which are much higher than those of previously reported siderite-based adsorbents. It was found that arsenic (III and V) sorption on CF-NCs occurred via bidentate corner-sharing surface complexation, predominantly without changes in the arsenic oxidation states. These results suggest that arsenic (III and V) can be attenuated by siderite in anoxic environments, and this attenuation can be even more effective when siderite is modified by incorporation of organic compounds such as citrate.

Original languageEnglish
Article number1773
Pages (from-to)1-22
Number of pages22
JournalNanomaterials
Volume10
Issue number9
DOIs
Publication statusPublished - 2020 Sept

Bibliographical note

Funding Information:
This work was supported by grants from the National Research Foundation of Korea funded by the Korea government (grant numbers 2017R1A2B4008454 and 2020R1I1A1A01073846), and the Korea Environment Industry & Technology Institute through the Underground Environmental Pollution Risk Management Technology Development Business Program funded by the Korea Ministry of Environment (grant number 2018002470002). Acknowledgments: This work was also supported by a Korea University Grant. We also thank the beamline scientists at 8C-Nano XAFS (Pohang Accelerator Laboratory, Korea) for their efforts in XAS analysis.

Funding Information:
Acknowledgments: This work was also supported by a Korea University Grant. We also thank the beamline scientists at 8C-Nano XAFS (Pohang Accelerator Laboratory, Korea) for their efforts in XAS analysis.

Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Keywords

  • Anoxic environment
  • Arsenic removal
  • Citrate
  • Nanocomposite
  • Siderite

ASJC Scopus subject areas

  • General Chemical Engineering
  • General Materials Science

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