Smectite-supported chain of iron nanoparticle beads for efficient clean-up of arsenate contaminated water

Kh Ashraf Uz-Zaman; Bhabananda Biswas; Mohammad Mahmudur Rahman; Ravi Naidu

doi:10.1016/j.jhazmat.2020.124396

Smectite-supported chain of iron nanoparticle beads for efficient clean-up of arsenate contaminated water

J Hazard Mater. 2021 Apr 5:407:124396. doi: 10.1016/j.jhazmat.2020.124396. Epub 2020 Nov 16.

Authors

Kh Ashraf Uz-Zaman¹, Bhabananda Biswas², Mohammad Mahmudur Rahman³, Ravi Naidu⁴

Affiliations

¹ Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW 2308, Australia; Department of Agricultural Chemistry, Sher-e-Bangla Agricultural University, Dhaka 1207, Bangladesh.
² Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW 2308, Australia; Future Industries Institute, STEM Unit, University of South Australia, Mawson Lakes, SA 5095, Australia.
³ Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address: Mahmud.Rahman@newcastle.edu.au.
⁴ Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address: Ravi.Naidu@newcastle.edu.au.

PMID: 33246822
DOI: 10.1016/j.jhazmat.2020.124396

Abstract

Prolonged exposure to inorganic arsenic (As) via drinking water is a major concern as it poses significant human health risks. Removal of As is crucial but requires effective and environment-friendly clean-up technology to avoid any additional risk to the environment. In this study, we developed Australian smectite (smec)-supported nano zero-valent iron (nZVI) composite for arsenate i.e., As(V) sorption. We used a range of tools, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and energy dispersion X-ray (EDS) spectroscopy to characterise the material. SEM and TEM images and elemental mapping of the composite reflect that the smectite layer was surrounded by a chain of iron nanobeads evenly distributed on clay particles, which is quite exceptional among currently available nZVIs. The maximum As(V) sorption capacity of this composite was 23.12 mg/g in the ambient conditions. Using X-ray photoelectron spectroscopy we unveiled chemical states of As and Fe before and after the sorption process. Additionally, the release of iron nanoparticles from the composite at various pHs (3-10) were found negligible, which demonstrates the effectiveness of smec-nZVI to remove As(V) from contaminated water without posing any secondary pollutant.

Keywords: Arsenate removal; Mechanism of sorption; Nano zero-valent iron; Smectite.