Revista Virtual de Química最新文献

{"title":"Evaluation of the Efficiency of Reverse Osmosis in the Treatment of Sanitary Landfill Leachate in the Metropolitan Region of the Rio de Janeiro","authors":"Ricardo Soares, Agatha Cristinne Prudêncio Soares, Beatriz César Maestá, M. Lippi, Carlos Eduardo Soares Canejo Pinheiro da Cunha","doi":"10.21577/1984-6835.20220059","DOIUrl":"https://doi.org/10.21577/1984-6835.20220059","url":null,"abstract":"The decomposition of the organic matter in municipal waste from landfills results in a highly polluted and toxic effluent, named sanitary landfill leachate. Due to the potential contamination for soil, groundwater and surface water bodies, the treatment of sanitary landfill leachate is essential to avoid environmental and public health damage. This study aims to evaluate the technical and environmental efficiency of reverse osmosis technology for the treatment of leachate in landfill from the Metropolitan Region of the Rio de Janeiro, Brazil. It was observed that the raw leachate from this landfill has highly polluting, and has chemical and physicochemical characteristics typical of mature landfills, with operation older than 5 years: pH = 7.85; ammonia nitrogen concentrations of 2,473.00 mg L -1 ; BOD 2,545.84 mg L -1 and COD 4,881.81 mg L -1 , respectively. Except for only one sampling, with phenol parameter, reverse osmosis was technically and environmentally efficient in mitigating pollutants present in the raw sanitary landfill leachate with excellent removal rates: E N (%) > 99%; E BOD (%) > 98%, and E COD (%) > 99%. After reverse osmosis treatment, the treated leachate was respecting Brazilian legislation and could be released into the local stream. During reverse osmosis treatment of 120 m 3 day -1 of leachate, prevented 107.84 kg year -1 of N from being released into nature; 110.95 kg year -1 of BOD, and 211.70 kg year -1 of COD, avoiding eutrophication from nearby rivers that inevitably flow into Guanabara Bay. It becomes a promising technology to face the impacts that pressure the Planetary Boundaries in the Anthropocene.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77263217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Control Parameters on the Stabilization of Mesophase Pitch Fibers","authors":"Caroline Jovine Bouças Guimarães, Alcino Palermo de Aguiar, Alexandre Taschetto de Castro","doi":"10.21577/1984-6835.20220027","DOIUrl":"https://doi.org/10.21577/1984-6835.20220027","url":null,"abstract":"This is an open-access article distributed under the terms of the Creative Commons Attribution License. Rev. Virtual Quim., 2022, no prelo, 1-13 ©2021 Sociedade Brasileira de Química a Instituto Militar de Engenharia, Seção de Engenharia Química, Praça General Tibúrcio 80, CEP 22290-270, Rio de Janeiro-RJ, Brasil. b Centro Tecnológico do Exército, Seção de Tecnologia de Materiais de Carbono, CEP: 23020-470, Rio de Janeiro-RJ, Brasil.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"12 19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84834578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrospun Fibers Applied on Heavy Metals Removal from Mining Wastewaters: a Systematic Review","authors":"Isabela C. Penna, Tarcísio S. Martins, João V. W. Silveira","doi":"10.21577/1984-6835.20220088","DOIUrl":"https://doi.org/10.21577/1984-6835.20220088","url":null,"abstract":"Mineral exploitation is an important activity and, due to its complexity, presents many issues related to environmental, economical and social aspects. The presence of heavy metals over the process is one of the most concerning problems to the environment and health. The releasing of residues containing such elements can be minimized properly with the use of new technologies. This study focuses on the application of electrospinning technology in order to produce nanoscaled structures, based on a systematic literature review. The use of this technique allows the production of very innovative materials, based on poly(acrylonitrile) or chitosan, for example. They act as adsorbent for heavy metals in wastewater treatment. Some of the advantages are related to the high specific surface area and the ability to modify the matrix structure, by functionalization or adding specific materials. In conclusion, it is possible to confirm its potential application in the mining industry, as a tertiary process on the wastewater treatment to remove diverse heavy metals.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"48 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76925113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gender Parity in Science: an Analysis of Womens's Participation in Argentina, Brazil and Paraguay","authors":"Liliane Cristina Battirola, Grazielle de Oliveira Setti, Diana Rodriguez Linares, Brenda Santana de Almeida, Marciana Pierina Uliana, Caroline da Costa Silva Goncalves","doi":"10.21577/1984-6835.20220004","DOIUrl":"https://doi.org/10.21577/1984-6835.20220004","url":null,"abstract":"This is an open-access article distributed under the terms of the Creative Commons Attribution License. Rev. Virtual Quim., 2022, no prelo, 1-12 ©2021 Sociedade Brasileira de Química a Universidade Federal da Integração Latino-Americana, Instituto LatinoAmericano de Tecnologia Infraestrutura e Território, Av. Presidente Tancredo Neves 6731, CEP 85867-900, Foz do Iguaçu-PR, Brasil. b Universidade Federal da Integração Latino-Americana, Instituto LatinoAmericano de Ciências da Vida e da Natureza, Av. Presidente Tancredo Neves 6731, CEP 85867-900, Foz do Iguaçu– PR, Brasil. c Universidade Estadual Paulista “Júlio de Mesquita Filho”, Faculdade de Ciências e Tecnologia, Rua Roberto Simonsen 305, CEP 19060-900, Presidente Prudente-SP, Brasil.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78100723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conversion of Methane to Methanol with Co-Generation of Electricity from Palladium Catalysts Supported in Carbon","authors":"Araceli J. Silva, Priscilla J. Zambiazi, Paulo V. R. Gomes, J. Nandenha, Camila M. Godoi, Rodrigo F. B. de Souza, Almir O. Neto, Nathália F. B. Azeredo","doi":"10.21577/1984-6835.20220101","DOIUrl":"https://doi.org/10.21577/1984-6835.20220101","url":null,"abstract":"The application of solid electrolyte reactors for methane oxidation and energy co-generation is attractive, especially with the use of catalysts synthesized from noble metals such as palladium. In this work, we prepared three different compositions of palladium on carbon support to evaluate the composition that had the greatest potential for energy generation. Catalysts in the proportions of 5, 10 and 20% of Pd/C were tested for the conversion of greenhouse gases into organic molecules of higher added value using electrochemical fuel cell solid electrolyte reactors. The focus of this work was the conversion of methane into methanol, using the fuel cell as a reactor and the commercial Pd/C as electrocatalyst. The electrocatalysts were tested at the anode, analyzed by infrared (IR) spectroscopy and their activities verified by experiments with rotating ring disk electrode (RRDE). Higher levels of palladium (Pd/C 20%) favored obtaining electrical power, and the intermediate composition (Pd/C 10%) showed a greater production of less oxidized compounds, such as methanol, in addition to generating electricity. Palavras-chaves: Oxidação de metano; catalisadores de paládio; célula a combustível.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82100632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the Generation of Technofossils by Different Coffee Brewing Methods During COVID-19 Pandemic","authors":"Ricardo Soares, Victor Oliveira Santos, Carlos Eduardo Soares Canejo Pinheiro da Cunha, Cleyton Martins da Silva, G. Arbilla, Wilson Machado","doi":"10.21577/1984-6835.20220025","DOIUrl":"https://doi.org/10.21577/1984-6835.20220025","url":null,"abstract":"Coffee is the second most consumed beverage in the world and an important international agricultural commodity, but the increasing use of single-serve coffee machines has led to major environmental concerns, as they produce non-biodegradable solid waste called technofossils, which are considered anthropogenic markers of the technosphere in the Anthropocene. Currently, Brazil is the world's largest coffee producer and the second largest consumer of this beverage. In this study, we evaluated the production of solid waste (biodegradable and technofossil) by the three most commonly used coffee preparation methods in Brazil during the COVID-19 pandemic: the \"Brazilian coffee brewing method\" (with cloth filter), electric coffee machine (with paper filter) and machines using single-serve Keurig Cups (R) (K-Cups). K-Cups produce a total waste mass 56% and 42% higher than those generated by the methods using the \"Brazilian coffee brewing method\" and the electric coffee machine, respectively. The K-Cups produce about 10 times more technofossil waste than the other two methods, but have a nearly equal distribution among all their generated waste (biodegradable: 50.5% and technofossil waste: 49.5%), with no statistically significant difference (p > 0.05). On the other hand, the \"Brazilian coffee brewing method\" and the one using an electric coffee machine, basically produce biodegradable solid waste, predominantly 93.5% for the \"Brazilian coffee brewing method\" and 84.0% for the one using an electric coffee machine, respectively. The technofossil residues generated mainly by the method that uses K-Cups are difficult to recycle, which poses increasing environmental risks if these solid residues are inadequately treated in the environment. This fact is worrisome, since during the COVID-19 pandemic a significant increase in the generation of municipal solid waste (>10%) was observed, as well as a significant increase in coffee consumption in Brazilian and worldwide households.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82114905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization and Validation of an analytical methodology for the Determination of As, Cd, Pb and Hg in Blood Matrix by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)","authors":"Santos Alves Vicentini Neto, Lisia Maria Gobbo dos Santos, Cristiane Barata Silva, Mayssa Andrade Fonseca, Carolina Duque Magalhães, Silvana do Couto Jacob","doi":"10.21577/1984-6835.20220044","DOIUrl":"https://doi.org/10.21577/1984-6835.20220044","url":null,"abstract":"The disorderly growth of cities has caused an environmental pollution problem. Recent studies show concern about the emission and deposition of metals in urban centers, thus, there is a risk of population contamination by elements that are proven harmful to health, such as As, Cd, Pb and Hg. The control of human contamination is done through products intended for human consumption, there is no population biomonitoring program, which could be an instrument to guide measures to prevent and promote collective health. Since human blood is an important biomarker and the analytical validation is one of the main instruments of quality assurance, this study intends to optimize and to validate an analytical methodology for determination of As, Cd, Pb and Hg in blood. Analyzes were performed in the INCQS and the quantification technique was ICP-MS. Accuracy, as assessed by the recovery test, was between 80-120% and a maximum deviation of 10%. All validation parameters presented values consistent with those established by INMETRO in the concentration range studied. The analytical methodology has been shown to be sensitive, specific, linear in the working range and good accuracy and precision were achieved, being adequate to quantify these elements in blood samples.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87553437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Chemistry Involved in CO2 Conversion: Challenges and Opportunities","authors":"Ana Luisa Abrantes Simões, Júlia Soares Rodrigues, Maria Helena Araujo, Sara Silveira Vieira","doi":"10.21577/1984-6835.20220091","DOIUrl":"https://doi.org/10.21577/1984-6835.20220091","url":null,"abstract":"This is an open-access article distributed under the terms of the Creative Commons Attribution License. Rev. Virtual Quim., 2022, no prelo, 1-16 ©2021 Sociedade Brasileira de Química 1 a Universidade Federal de Minas Gerais, Departamento de Química, CEP 31270901, Belo Horizonte-MG, Brasil. b Universidade Federal Fluminense, Instituto de Química, Departamento de Química Inorgânica, CEP 24020-141, Niterói-RJ, Brasil.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"139 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87998796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Economic Model as a Decision-Making Tool for Biodiesel Production from Microalgae","authors":"Bruno Luciano Carneiro Alves de Oliveira, Flávia Talarico Saia, Jose Juan Barrera Alba, Cláudia Aparecida de Mattos","doi":"10.21577/1984-6835.20210096","DOIUrl":"https://doi.org/10.21577/1984-6835.20210096","url":null,"abstract":"This is an open-access article distributed under the terms of the Creative Commons Attribution License. Rev. Virtual Quim., 2022, 14 (1), 40-45 ©2022 Sociedade Brasileira de Química a Centro Universitário FEI, Departamento de Engenharia Mecânica, CEP 09850901, São Bernardo do Campo-SP, Brasil. b Universidade Federal de São Paulo, Instituto do Mar, Campus Baixada Santista, CEP 11070-100, Santos-SP, Brasil.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83763428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of Nickel in Topical Repellents by Graphite Furnace Atomic Absorption Spectrometry Through Direct Emulsion Injection","authors":"C. Rodrigues de Paula, Regina Fonsêca de Almeida, João Victor Meirelles Leite","doi":"10.21577/1984-6835.20220068","DOIUrl":"https://doi.org/10.21577/1984-6835.20220068","url":null,"abstract":"A method for simple and rapid determination of nickel from topical repellents by graphite furnace atomic absorption spectrometry (GFAAS) through direct introduction of the samples in the form of emulsion is proposed in this work. The method was optimized by evaluating the influence of several variables such as the mass of sample, concentration and nature of the acid, sonication time employed in the procedure and emulsion stability. The curves of pyrolysis and atomization were constructed in order to evaluate the effect of the possible chemical interference. The optimized conditions were achieved when 500 mg of the sample in 5 mL of aqueous solution of 0.1 mol L −1 HNO 3 and 0.1 mol L −1 sodium dodecyl sulfate (SDS) and the analytical signals remained stable until 55 min, without statistically significant variation in the signal. The developed method was applied in the determination of nickel in three samples of topical repellents and the results were compared with those obtained by acid digestion. There was no statistical difference between the obtained values at 95% confidence level when a paired Student t-test was applied.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88702184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}