Iron mining wastes collected from Mariana disaster: Reuse and application as catalyst in a heterogeneous electro-Fenton process

Author(s)

dos Santos, Alexsandro Jhones ^[1] ; Cunha, Graziele da Costa ^[2] ; Souza Cruz, Daiane Requiao ^[2] ; Cruz Romao, Luciane Pimenta ^{[3, 2]} ; Martinez-Huitle, Carlos Alberto ^{[1, 3]}

Affiliation

^[1] Univ Fed Rio Grande do Norte, Inst Chem, LEAA, BR-59078970 Natal, RN - Brazil

^[2] Univ Fed Sergipe, Dept Chem, LEMON, BR-49100000 Sao Cristovao, SE - Brazil

^[3] UNESP, Inst Chem, Natl Inst Alternat Technol Detect Toxicol Evaluat, POB 355, BR-14800900 Araraquara, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 848, SEP 1 2019.
• Web of Science Citations: 0

Abstract

A simple and environmental friendly strategy for recycling iron mining wastes from the Mariana disaster, one of the biggest environmental disasters in Brazil, involved the synthesis of a magnetic hybrid ( HbLM) material at ambient temperature. XRD analysis revealed formation of the cobalt ferrite phase, while FTIR and TGA confirmed the presence of NOM in the structures. The HbLM showed high surface area of about 167.9 m(2) g(-1). Heterogeneous electro-Fenton (EF)-HbLM process achieved the total decolorization of a model pollutant, the Acid blue 29 diazo dye, after 20 min of electrolysis: while the electrochemical oxidation with hydrogen peroxide generation ( EO-H2O2) only led to 62% of color removal. The limit current density was 333 mA cm(-2), above this value the parasitic reactions overlapped, consequently the efficiency of the process decreased. At pH 3.0, complete color removal was achieved after 20 min of treatment while 60 min were necessary at pH 7.0 (natural pH). This means that, at neutral pH, the process is feasible and the acidification of the medium is not necessary to promote the main reactions. This work provides an example of a system to remove toxic contaminants from wastewater following the principles of green chemistry and industrial symbiosis, with sequential reuse of wastes and the generation of new raw materials with added commercial and technological values. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants