University of Oulu

Bello, A., Martincigh, B. S., Nyamori, V. O., & Leiviskä, T. (2023). Vanadium removal and floc characteristics of tannin biocoagulants and iron sulphate in the treatment of mine effluent. Chemical Engineering Journal, 476, 146665. https://doi.org/10.1016/j.cej.2023.146665

Vanadium removal and floc characteristics of tannin biocoagulants and iron sulphate in the treatment of mine effluent

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Author: Bello, Adedayo1; Martincigh, Bice S.2; Nyamori, Vincent O.2;
Organizations: 1Chemical Process Engineering, University of Oulu, P.O. Box 4300, Oulu FIN-90014, Finland
2School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2.4 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe20231026141485
Language: English
Published: Elsevier, 2023
Publish Date: 2023-10-26
Description:

Abstract

This study compared the performance of tannin (quebracho and spruce) and iron sulphate (FS) coagulants for the removal of vanadium from effluent derived from an abandoned vanadium mine. The efficacy of the materials was studied at the natural pH of the mine effluent (7.4), and at adjusted pH levels of 4 and 9. The quebracho tannin coagulant (QT) recorded impressive turbidity and vanadium removals of above 88% over a wide pH range. However, the spruce tannin coagulant (ST) was not as effective at pH 9 (39%) although it showed an improved vanadium removal of 46% and 70% at pH 7.4 and 4, respectively. This was attributed to the lower charge density of ST than that of QT, and to a loss of cationic properties at pH 9. FS performed better in terms of vanadium removal (pH 4: 86%, pH 7: 98%, pH 9: 100%) with lower coagulant doses, although effective turbidity removal required precise pH control. QT produced the largest flocs and the highest floc regrowth at pH 4 and 7. Under alkaline conditions, tannin coagulants exhibit no regrowth, which implies that a careful flocculation and floc separation step is needed. The natural organic matter fractionation results revealed that FS effectively removed hydrophilic carbon (76%) in a pH-controlled mine effluent better than tannin coagulants (QT: 12% and ST: 22%) from the pH 4 effluent; however, ST removed hydrophobic carbon entirely. All coagulants adequately removed humic substances, with FS being the most efficient (88%), followed by ST (53%) and QT (47%). X-ray photoelectron spectroscopy (XPS) analysis of jar test residues showed that some of the vanadium removed existed in the V(IV) oxidation state.

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Series: Chemical engineering journal
ISSN: 1385-8947
ISSN-E: 1873-3212
ISSN-L: 1385-8947
Volume: 476
Article number: 146665
DOI: 10.1016/j.cej.2023.146665
OADOI: https://oadoi.org/10.1016/j.cej.2023.146665
Type of Publication: A1 Journal article – refereed
Field of Science: 215 Chemical engineering
218 Environmental engineering
Subjects:
Funding: The authors would like to thank the EU and the Academy of Finland (Finland, grant number 345509), the Ministry of Health (Israel), Innovationsfonden Denmark (Denmark) and the Water Research Commission (South Africa) for funding, in the frame of the collaborative international consortium (REWA, Reduction and assessment of antimicrobial resistance and emerging pollutants in natural-based water treatment systems) financed under the ERA-NET AquaticPollutants Joint Transnational Call (GA No 869178). ERA-NET is an integral part of the activities developed by the Water, Oceans and AMR Joint Programming Initiatives. Adedayo Bello has also received funding from the University of Oulu graduate school Technology and Natural Sciences Doctoral Programme (TNS-DP) for his doctoral research.
Academy of Finland Grant Number: 345509
Detailed Information: 345509 (Academy of Finland Funding decision)
Dataset Reference: The raw data required to reproduce these findings are available for download from:
  https://doi.org/10.23729/92836a46-1edd-4266-83a1-150f776c69e5
Copyright information: © 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
  https://creativecommons.org/licenses/by/4.0/