Application of Advanced Oxidation Process Using Ozonation Assisted with Hydrogen Peroxide for Organic Compounds Removal from Bayer Liquor

Author(s)

Soplin Pastor, Miguel Antonio ; Botelho Junior, Amilton Barbosa ; Romano Espinosa, Denise Crocce ; Soares Tenorio, Jorge Alberto ; Galluzzi Baltazar, Marcela Dos Passos

• Document type: Journal article
• Source: OZONE-SCIENCE & ENGINEERING; v. 44, n. 3, p. 11-pg., 2021-05-20.

Abstract

One of the alumina industry's main problems is the organic matter in the Bayer liquor during the Bayer Process released in the bauxite digestion process and accumulating in the process. It reduces as process efficiency and results in impurities in the final product. Several studies have shown that removing organic matter by ozonation can be attractive for industrial applications since ozone can be generated in situ and achieve faster results. For this reason, the goal of the present work was to study the removal of organic matter from the Bayer liquor. The effect of ozone dosage and O-3/H2O2 combination was evaluated at 40 degrees C and 80 degrees C. Results indicated that the organic matter mineralization achieved 19% at 80 degrees C, using 6.5 g/L of O-3 and 0.05 mol/L of H2O2, where 95.4% generated carbon dioxide. At the same conditions, 45.6% of oxalate was degraded. The UV/vis analyses demonstrated the decrease in organic chain size and the color of the samples before and after the oxidation process. An advanced oxidation process (O-3 and O-3/H2O2 combination) effectively removed a range of organic impurities from the Bayer liquor impacting the quality of the final product. (AU)

• FAPESP's process: 12/51871-9 - Study Center for Technology in Waste Solid Treatment and Recycling - SCTWSTR
• Grantee: Jorge Alberto Soares Tenório
• Support Opportunities: Research Projects - Thematic Grants