Synthesis of zerovalent iron from water treatment residue as a conjugate with kaolin and its application for vanadium removal

Adedayo Bello; Tiina Leiviskä; Ruichi Zhang; Juha Tanskanen; Paulina Maziarz; Jakub Matusik; Amit Bhatnagar

doi:10.1016/j.jhazmat.2019.04.056

Synthesis of zerovalent iron from water treatment residue as a conjugate with kaolin and its application for vanadium removal

J Hazard Mater. 2019 Jul 15:374:372-381. doi: 10.1016/j.jhazmat.2019.04.056. Epub 2019 Apr 17.

Authors

Adedayo Bello¹, Tiina Leiviskä², Ruichi Zhang¹, Juha Tanskanen¹, Paulina Maziarz³, Jakub Matusik³, Amit Bhatnagar⁴

Affiliations

¹ University of Oulu, Chemical Process Engineering, P.O. Box 4300, FIN-90014, University of Oulu, Oulu, Finland.
² University of Oulu, Chemical Process Engineering, P.O. Box 4300, FIN-90014, University of Oulu, Oulu, Finland. Electronic address: tiina.leiviska@oulu.fi.
³ AGH University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection, Department of Mineralogy, Petrography and Geochemistry, al. Mickiewicza 30, 30-059, Krakow, Poland.
⁴ Department of Environmental and Biological Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland.

PMID: 31028916
DOI: 10.1016/j.jhazmat.2019.04.056

Abstract

This study was aimed at examining the possible utilization of iron-rich groundwater treatment sludge in the synthesis of zerovalent iron (ZVI) as a conjugate with kaolin clay (Slu-KZVI), and its application for vanadium adsorption from aqueous solutions. Iron was extracted from the sludge using 1 M HCl and was used in ZVI synthesis by the sodium borohydride reduction method. The characteristics and performance of Slu-KZVI were compared to a kaolin modified with synthetic iron (FeCl₃·6H₂O) (Syn-KZVI). Adsorption results showed a competitive performance by both classes of KZVI, with Syn-KZVI slightly outperforming Slu-KZVI. X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy confirmed the formation of Fe⁰ on the core-shell structure of both modified adsorbents. In addition, the surface analysis of Slu-KZVI indicated the presence of P and Ca to a small extent, originating from the sludge. Both classes of sorbents performed better in solutions with acidic and neutral pH values (3-7). Surface complexation was thought to be the primary mechanism whereas simultaneous V(V) reduction and Fe oxidation (redox) reactions may also have taken place to some extent. A sorption test with groundwater confirmed that adsorbents were able to reduce vanadium to a very low concentration.

Keywords: Adsorption; Groundwater; Kaolin clay; Water treatment residual; Zerovalent iron.

Publication types

Research Support, Non-U.S. Gov't