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Mineral characterization of the biogenic Fe(III)(hydr)oxides produced during Fe(II)-driven denitrification with Cu, Ni and Zn.

Authors :
Kiskira K
Papirio S
Mascolo MC
Fourdrin C
Pechaud Y
van Hullebusch ED
Esposito G
Source :
The Science of the total environment [Sci Total Environ] 2019 Oct 15; Vol. 687, pp. 401-412. Date of Electronic Publication: 2019 Jun 08.
Publication Year :
2019

Abstract

The recovery of iron and other heavy metals by the formation of Fe(III) (hydr)oxides is an important application of microbially-driven processes. The mineral characterization of the precipitates formed during Fe(II)-mediated autotrophic denitrification with and without the addition of Cu, Ni, and Zn by four different microbial cultures was investigated by X-ray fluorescence (XRF), Raman spectroscopy, scanning electron microscopy equipped with energy dispersive X-Ray analyzer (SEM-EDX), Fourier transform infrared spectroscopy (FTIR) and X-ray Powder Diffraction (XRD) analyses. Fe(II)-mediated autotrophic denitrification resulted in the formation of a mixture of Fe(III) (hydr)oxides composed of amorphous phase, poorly crystalline (ferrihydrite) and crystalline phases (hematite, akaganeite and maghemite). The use of a Thiobacillus-dominated mixed culture enhanced the formation of akaganeite, while activated sludge enrichment and the two pure cultures of T. denitrificans and Pseudogulbenkiania strain 2002 mainly resulted in the formation of maghemite. The addition of Cu, Ni and Zn led to similar Fe(III) (hydr)oxides precipitates, probably due to the low metal concentrations. However, supplementing Ni and Zn slightly stimulated the formation of maghemite. A thermal post-treatment performed at 650 °C enhanced the crystallinity of the precipitates and favored the formation of hematite and some other crystalline forms of Fe associated with P, Na and Ca.<br /> (Copyright © 2019 Elsevier B.V. All rights reserved.)

Details

Language :
English
ISSN :
1879-1026
Volume :
687
Database :
MEDLINE
Journal :
The Science of the total environment
Publication Type :
Academic Journal
Accession number :
31212147
Full Text :
https://doi.org/10.1016/j.scitotenv.2019.06.107