Enhanced detoxification of Cr6+ by Shewanella oneidensis via adsorption on spherical and flower-like manganese ferrite nanostructures

Diana S Raie; Ioannis Tsonas; Melisa Canales; Stefanos Mourdikoudis; Konstantinos Simeonidis; Antonis Makridis; Dimitrios Karfaridis; Shanom Ali; Georgios Vourlias; Peter Wilson; Laurent Bozec; Lena Ciric; Nguyen Thi Kim Thanh

doi:10.1039/d2na00691j

Enhanced detoxification of Cr⁶⁺ by Shewanella oneidensis via adsorption on spherical and flower-like manganese ferrite nanostructures

Nanoscale Adv. 2023 Jan 16;5(11):2897-2910. doi: 10.1039/d2na00691j. eCollection 2023 May 30.

Authors

Diana S Raie^{1

2}, Ioannis Tsonas³, Melisa Canales⁴, Stefanos Mourdikoudis^{1

2}, Konstantinos Simeonidis⁵, Antonis Makridis⁵, Dimitrios Karfaridis⁵, Shanom Ali⁶, Georgios Vourlias⁵, Peter Wilson⁶, Laurent Bozec⁷, Lena Ciric⁴, Nguyen Thi Kim Thanh^{1

2}

Affiliations

¹ Biophysics Group, Department of Physics and Astronomy, University College London Gower Street London WC1E 6BT UK ntk.thanh@ucl.ac.uk http://www.ntk-thanh.co.uk.
² UCL Healthcare Biomagnetics and Nanomaterials Laboratories 21 Albemarle Street London W1S 4BS UK.
³ UCL Electronic and Electrical Engineering, UCL Gower Street London WC1E 7JE UK.
⁴ Healthy Infrastructure Research Group, Department of Civil, Environmental & Geomatic Engineering, UCL Gower Street London WC1E 6BT UK.
⁵ Department of Physics, Aristotle University of Thessaloniki 54124 Thessaloniki Greece.
⁶ Environmental Research Laboratory, ClinicalMicrobiology and Virology, University College London Hospitals NHS Foundation Trust London UK.
⁷ Faculty of Dentistry, University of Toronto Toronto Ontario Canada.

Abstract

Maximizing the safe removal of hexavalent chromium (Cr⁶⁺) from waste streams is an increasing demand due to the environmental, economic and health benefits. The integrated adsorption and bio-reduction method can be applied for the elimination of the highly toxic Cr⁶⁺ and its detoxification. This work describes a synthetic method for achieving the best chemical composition of spherical and flower-like manganese ferrite (Mn_xFe_3-xO₄) nanostructures (NS) for Cr⁶⁺ adsorption. We selected NS with the highest adsorption performance to study its efficiency in the extracellular reduction of Cr⁶⁺ into a trivalent state (Cr³⁺) by Shewanella oneidensis (S. oneidensis) MR-1. Mn_xFe_3-xO₄ NS were prepared by a polyol solvothermal synthesis process. They were characterised by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), dynamic light scattering (DLS) and Fourier transform-infrared (FTIR) spectroscopy. The elemental composition of Mn_xFe_3-xO₄ was evaluated by inductively coupled plasma atomic emission spectroscopy. Our results reveal that the oxidation state of the manganese precursor significantly affects the Cr⁶⁺ adsorption efficiency of Mn_xFe_3-xO₄ NS. The best adsorption capacity for Cr⁶⁺ is 16.8 ± 1.6 mg Cr⁶⁺/g by the spherical Mn_0.2²⁺Fe_2.8³⁺O₄ nanoparticles at pH 7, which is 1.4 times higher than that of Mn_0.8Fe_2.2O₄ nanoflowers. This was attributed to the relative excess of divalent manganese in Mn_0.2²⁺Fe_2.8³⁺O₄ based on our XPS analysis. The lethal concentration of Cr⁶⁺ for S. oneidensis MR-1 was 60 mg L^-1 (determined by flow cytometry). The addition of Mn_0.2²⁺Fe_2.8³⁺O₄ nanoparticles to S. oneidensis MR-1 enhanced the bio-reduction of Cr⁶⁺ 2.66 times compared to the presence of the bacteria alone. This work provides a cost-effective method for the removal of Cr⁶⁺ with a minimum amount of sludge production.