Mine tailings in a redox-active environment: Iron geochemistry and potential environmental consequences

Autor(es)

Queiroz, Hermano Melo ^[1] ; Ruiz, Francisco ^[1] ; Deng, Youjun ^[2] ; de Souza Junior, Valdomiro S. ^[3] ; Ferreira, Amanda Duim ^[1] ; Luis Otero, Xose ^[4] ; Camelo, Danilo de Lima ^[5] ; Bernardino, Angelo Fraga ^[6] ; Ferreira, Tiago Osorio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Soil Sci, Piracicaba, SP - Brazil

^[2] Texas A&M Univ, Dept Soil & Crop Sci, College Stn, TX 77843 - USA

^[3] Univ Fed Rural Pernambuco, Dept Agron, Av Dom Manoel de Medeiros S-N, BR-52171900 Recife, PE - Brazil

^[4] Univ Santiago de Compostela, Fac Biol, CRETUS Inst, Dept Edafol & Quim Agr, Santiago De Compostela - Spain

^[5] Univ Fed Espirito Santo, Dept Agron, Alegre, ES - Brazil

^[6] Univ Fed Espirito Santo, Dept Oceanog, BR-29075910 Vitoria, ES - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 807, n. 3 FEB 10 2022.
• Citações Web of Science: 1

Resumo

Iron (Fe) oxyhydroxides provide many functions in soils, mainly owing to their large surface area and high surface charge density. The reactivity of Fe oxyhydroxides is function of their mineralogical characteristics (e.g., crystallinity degree and crystal size). Detailed studies of these features are essential for predicting the stability and reactivity of these minerals within soil and sediments. The present study aimed to evaluate geochemical changes in Fe-rich tailings after the world's largest mining disaster in SE Brazil (in 2015) and to predict the potential environmental implications for the estuary. The mineralogical characteristics of the tailings were studied at three different times (2015, 2107, and 2019) to assess how an active redox environment affects Fe oxyhydroxides and to estimate the time frame within which significant changes occur. The study findings indicate a large decrease in the Fe oxyhydroxides crystallinity, which were initially composed (93%) of highly crystalline Fe oxyhydroxides (i.e., goethite and hematite) and 6.7% of poorly crystalline Fe oxyhydroxides (i.e., lepidocrocite and ferrihydrite). Within 4 years the mineralogical features of Fe oxyhydroxides had shifted, and in 2019 poorly crystalline Fe oxyhydroxides represented 47% of the Fe forms. Scanning electron microscope micrographs and the mean crystal size evidenced a decrease in particle size from 109 nm to 49 nm for goethite in the d111 direction. The changes in mean crystal size increased the reactivity of Fe oxyhydroxides, resulting in a greater number of interactions with cationic and anionic species. The decreased crystallinity and increased reactivity led to the compounds being more susceptible to reductive dissolution. Overall, the findings show that the decrease in crystallinity along with higher susceptibility to reductive dissolution of Fe oxyhydroxides can affect the fate of environmentally detrimental elements (e.g., phosphorus and trace metals) thereby increasing the concentration of these pollutants in estuarine soils and waters. (c) 2021 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 19/17413-2 - Processos redox controlando a dinâmica de metais associados a óxidos de Fe no sedimentos do estuário do rio Doce após o desastre de Mariana
• Beneficiário: Hermano Melo Queiroz
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 19/14800-5 - Plantas estuarinas e seu controle na biogeoquímica de metais em solos impactados pelo `desastre de Mariana´
• Beneficiário: Amanda Duim Ferreira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 19/19987-6 - Solos e plantas do estuário do Rio Doce e seu controle sobre a biogeoquímica de ferro e metais em resposta ao desastre de Mariana (MG)
• Beneficiário: Tiago Osório Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/04259-2 - Biogeoquímica de ferro e seu controle sobre a dinâmica de metais traço nos solos do estuário do Rio Doce após o "desastre de Mariana"
• Beneficiário: Hermano Melo Queiroz
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 18/08408-2 - Estudos comparativos de transformações minerais de nanopartículas de óxidos de ferro em solos e sedimentos afetados por rejeitos de mineração e seus impactos na mobilização e fixação de metais pesados em dois ambientes redox contrastantes
• Beneficiário: Tiago Osório Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/18324-3 - Qualidade do solo e estabilização da matéria orgânica em tecnossolos construídos com rejeitos de mineração de calcário
• Beneficiário: Francisco Ruiz
• Modalidade de apoio: Bolsas no Brasil - Doutorado