EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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5 resultados
Resultados da Pesquisa
Item Removal of cephalexin and erythromycin antibiotics, and their resistance genes, by microalgae-bacteria consortium from wastewater treatment plant secondary effluents.(2021) Rodrigues, Daniel Aparecido da Silva; Cunha, Camila Cristina Rodrigues Ferreira da; Espirito Santo, Daiana Rocha do; Barros, André Luis Corrêa de; Pereira, Andressa Rezende; Silva, Silvana de Queiroz; Santiago, Aníbal da Fonseca; Afonso, Robson José de Cássia FrancoAntibiotics have become a concern in the aquatic environments owing to the potential development of bacterial resistances. Thus, this study evaluated the removal of cephalexin (CEP) and erythromycin (ERY) from a local wastewater treatment plant (WWTP) effluent, mediated by microalgae-bacteria consortium. Likewise, the removal of correlated antibiotics resistance genes blaTEM and ermB was also assessed. The incubation results showed that the added concentrations of selected antibiotics did not restrain the consortium growth. Moreover, CEP and ERY were almost completely removed after the cultivation period, reaching total removals of 96.54% and 92.38%, respectively. The symbiotic interaction between microalgae and bacteria plays a role in the kinetics removal of CEP and ERY. The abundance of blaTEM and ermB was reduced by 0.56 and 1.75 logs, respectively. Lastly, our results suggest that technology based on natural microalgae-bacteria consortium could be a potential alternative to improve the quality of WWTP effluents.Item Antibiotic consumption in developing countries defies global commitments : an overview on Brazilian growth in consumption.(2020) Castro, Paulo Bernardo Neves e; Rodrigues, Daniel Aparecido da Silva; Roeser, Hubert Mathias Peter; Santiago, Aníbal da Fonseca; Afonso, Robson José de Cássia FrancoFaster spread of epidemics has turned local concerns into global crises; antimicrobial resistance (AMR) is being considered a major threat to public health in the twenty-first century. Antibiotic misuse plays a great role in accelerated AMR; thus, understanding and discussing consumption patterns has been a trend topic over the past years. Developing countries, such as Brazil, have high growth rates in antibiotic consumption, potentially impacting global environmental safety. This study presents the compiled information from the Brazilian Health Regulatory Agency (ANVISA) on antibiotic dispensation across the country and maps the consumption trends between the years of 2013 and 2016. The most consumed substances were beta-lactams (amoxicillin and cephalexin) and macrolides (azithromycin). National relative growth consumption in the mentioned period was 18%. At the local level, growth of consumption ranged from 4 to 85%, with rampage growth concentrated in the North and Northeast regions. Brazilian laws, such as restriction of over-the-counter sales and mandatory report on dispensation, seem to have little effect on the national antibiotic consumption growth. This phenomenon growth is still elevated if compared with developed countries, demonstrating the need for further surveillance as well as coordinated efforts aiming at antibiotic use and AMR prevention.Item Biodegradation of sulfamethoxazole by microalgae-bacteria consortium in wastewater treatment plant effluents.(2020) Rodrigues, Daniel Aparecido da Silva; Cunha, Camila Cristina Rodrigues Ferreira da; Freitas, Mylena Gomes; Barros, André Luis Corrêa de; Castro, Paulo Bernardo Neves e; Pereira, Andressa Rezende; Silva, Silvana de Queiroz; Santiago, Aníbal da Fonseca; Afonso, Robson José de Cássia FrancoSulfamethoxazole (SMX) has been commonly detected in wastewater treatment plant (WWTP) effluents. SMX and other antibiotics can be considered as environmental contaminants of emerging concern. Due to their toxicity effects and their potential for the development of bacterial resistance their presence in aquatic compartment becomes a threat to human health. This study evaluated the bioremediation of SMX in WWTP effluents using a tertiary treatment composed by microalgae-bacteria consortium under low intensity artificial LED illumination, and also the assessment of sulfonamide resistance gene (sul1). The removal of SMX from WWTP effluents were 54.34 ± 2.35%, in which the microalgae-bacteria consortium improves the removal performance of SMX. The main process of SMX removal can be attributed to the symbiotic biodegradation by bacteria due to the increase of oxygen released by the microalgae photosynthetic process. Therefore, the microalgae-bacteria consortium used in this study, demonstrated to be a promising alternative for bioremediation of SMX, with potential for removal others contaminants from wastewater effluent. However, the residual SMX and the relative abundance of antibiotics resistance genes (ARG) found in this study suggest that SMX contributes to selective pressure for ARG maintenance and proliferation inWWTP effluent. Thus, further studies to removal ARG from WWTP effluent are needed.Item Determination of rare earth elements in Fe-minerals using external calibration by LA-ICP-MS and application on Cauê Iron Formation (Brazil).(2020) Sousa, Denise Versiane Monteiro de; Abreu, Adriana Trópia de; Sampaio, Geraldo Magela Santos; Lana, Cristiano de Carvalho; Rodrigues, Daniel Aparecido da Silva; Nalini Júnior, Hermínio AriasThe rare earth elements (REE) composition in Fe-mineral phases is an important tool in iron formation studies to obtain information about parent rocks and environmental and paragenetic processes. However, the determination of REE presents some difficulties, such as the low concentration of these elements, matrix complexity and lack of iron matrix certified reference materials. The aim of the present work is to propose an analytical method to determine the REE plus Y (REE + Y) contents at trace levels in Fe-(hydr)oxides by the laser ablation ICPquadrupoleMS technique, using external calibration. The calibration curves were obtained from analyses of reference materials with different matrices, and the analytical conditions were checked on the NIST 614 glass. The linearity (R2 ≥ 0.98), limit of detection (0.002–0.044 μg g−1), limit of quantification (0.008–0.146 μg g−1), recovery (88.4–112.4%), and intraday (0.1–14.1%) and interday (1.6–17.8%) precision were systematically assessed. The results obtained showed that the method is fit for the purpose and showed evidence of a nonsignificant interference of the matrix. Thus, the developed procedure was applied in the analyses of magnetite, martite, hematite, and goethite grains from Cauê Iron Formation (Brazil). The REE + Y patterns of the minerals are consistent with the previous study of bulk analyses on whole rocks and highlight the postdepositional signature of these elements in banded iron formations.Item Assinatura geoquímica da hematita compacta do Quadrilátero Ferrífero – MG : uma contribuição para a compreensão de sua gênese.(2015) Rodrigues, Daniel Aparecido da Silva; Nalini Júnior, Hermínio AriasO estudo da gênese da hematita compacta do Quadrilátero Ferrífero (QFe) é motivo de interesse tanto científico quanto econômico. No entanto, têm-se poucos trabalhos sobre estudos geoquímicos relevantes que possam contribuir para a gênese do minério hematítico. A hematita compacta é um tipo especial de minério de ferro, pois apresenta elevado teor em ferro, baixo teor em sílica e textura maciça. Há certa controvérsia sobre o tipo de mineralização envolvido na formação da hematita compacta, alguns autores defendem a origem supergênica e outros a participação de fluidos hipogênicos-metamórficos-hidrotermais na formação desse tipo de minério. Esse trabalho tem como objetivo contribuir para o entendimento da gênese da hematita compacta. As amostras para estudo foram coletadas em três regiões distintas do QFe: Complexo Itabirito (Minas do Pico, Galinheiro e Sapecado), Complexo Fazendão (Minas São Luiz, Tamanduá e Almas) e Complexo Itabira (Minas Conceição e Periquito). Foram coletadas amostras de hematita compacta e amostras de itabirito, com a intenção de comparar e verificar se há semelhança geoquímica entre ambas, sobretudo no que se refere à composição de elementos-traços, inclusive os elementos terras raras (ETR’s). Fez-se a caracterização mineralógica das amostras por técnicas microscópicas (Microscopia Óptica e MEV-EDS) e por DRX. A composição da hematita compacta é bastante simples, sendo constituída, essencialmente, por hematita (valor médio de Fe2O3 = 98,0%). Em todas as amostras foram observados a presença de magnetita (FeO.Fe2O3 = 3,0 a 20,0%) e, ainda em algumas amostras foram evidenciados a martitização, que é um processo de alteração oxidativa, em que a magnetita se transforma em hematita. Já as amostras de itabirito são constituídas, principalmente, por camadas alternadas de hematita e quartzo. A determinação de ferro total foi realizada pelo método titulométrico com dicromato de potássio, os valores obtidos variaram de 98,51 a 99,86%; 87,45 a 98,51% e 98,59 a 99,74% para as amostras de hematita compacta dos Complexos Itabirito, Fazendão e Itabira, respectivamente. Todas as amostras apresentam valores de óxido ferroso (FeO) inferiores a 1,0%. As análises geoquímicas foram realizadas para se determinar os elementos maiores e menores por ICP-OES e a determinação dos elementos-traços, inclusive os ETR’s + Y (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Tm, Yb e Lu) por ICP-MS. As amostras de hematita compacta do Complexo Itabirito são as que apresentam maiores teores de Fe total médio e maiores teores médio de elementos-traços analisados quando comparado com os outros complexos estudados. Todas as amostras analisadas apresentam anomalias positiva de Eu, indicando uma possível contribuição de fontes hidrotermais na formação da hematita compacta. A maioria das amostras apresentam anomalias positivas de Ce, sugerindo uma ambiente redutor na época de formação dessas amostras. A variação na concentração de elementos-traços, inclusive os ETR’s + Y, pode indicar heterogeneidade na concentração original dos fluidos mineralizantes ou nos processos envolvidos na gênese desse minério. Apesar das variações de concentração, observa-se um enriquecimento dos ETRP em relação aos ETRL na maioria das amostras.