No abstract

Brazil is the second largest producer of electronic waste in the Americas, with a production that grows each year and only 10% of it being treated in its own way. Additionally, given the typical chemical composition of this type of residue, it can be possible to recover valuable metals, such as copper, gold, silver, and platinum. Presently, Brazil does not have an industrial plant devoted to such extractive activity using electronic waste, with most of its treatment carried out abroad. The research hypothesis of this manuscript is that universities and their communities could develop sources of raw materials for such extraction processes and, therefore, deserve attention for the creation of collection points and partnerships. In this context, there is a need to understand this community behavior regarding the acquisition, storage, and disposal of electronic equipment, as well as information about topics related to electronic waste management and recycling. To implement such a study for the higher education community in Rio de Janeiro, a form was created covering several topics on the subject, which was disseminated among the teachers, students, employees, and family members of two main state universities. It was determined that the studied group has more than 16.96 million mobile phones in hibernation, in addition to other equipment, with an estimated stockpile value of USD 67.45 million for the studied group in the metropolitan area of Rio de Janeiro. If extrapolated to all of Brazil, this could be as high as USD 797.50 million for the studied group. This information will be used in future projects to assess the economic potential of an industrial plant dedicated to metal recovery in Brazil. However, the present study also identified an important lack of knowledge regarding proper waste disposal and solid waste policies among this well-educated group. It became clear that without appropriate information regarding collection points and knowledge on how to deal with obsolete devices, the access to this source of raw material could be a hinderance to future extraction projects in the area.

Resumo: Um determinado tipo de efluente de uma indústria petroquímica foi avaliado neste estudo para aplicação em um processo de coagulação, utilizando os coagulantes FeCl 3 , Al 2 (SO 4 ) 3 e policloreto de alumínio (PAC) no processo de coagulação. Além desses, um polímero aniônico (Magnafloc), também foi utilizado. Durante os ensaios de coagulação/floculação, conduzidos em Jar test, os melhores resultados obtidos com adição de FeCl 3 foram alcançados em uma concentração de 300 mg/L no valor de pH igual a 9,0, na presença ou não de Magnafloc na concentração de 1,5 mg/L. Sob estas condições obteve-se uma remoção de turbidez de 90% e 92,8%, e de óleo e graxas de 91,6% e 86,8%. Já ao utilizar o Al 2 (SO 4 ) 3 , os melhores resultados foram alcançados a uma concentração de 300 mg/L em valor de pH igual a 9,0, também na presença ou não do polímero Magnafloc a uma concentração de 1,0 mg/L. Nestes ensaios a remoção de turbidez foi de 93,5% e 97,3%, enquanto que a de óleo e graxas foi de 91,5% e 93,3%. Ao adicionar o PAC, em uma concentração de 150 mg/L e no valor de pH igual a 8,0, sem e com adição de Magnafloc na concentração de 1,0 mg/L, os resultados apresentados foram 96,5% e 98,2% na remoção de turbidez, e 91,2% e 95% na remoção de óleos e graxas. Após a realização de todos os ensaios, concluiu-se que para este determinado tipo de efluente, o PAC (150 mg/L), em pH 8,0 e na presença do polímero aniônico Magnafloc (1,0 mg/L) se apresentou como a melhor escolha para o tratamento, por promover a melhor remoção de turbidez e óleos e graxas. Palavras-Chave:Coagulação, floculação, turbidez, óleos e graxas. Abstract:One type of effluent in a petrochemical industry has been reported in this study for application in a coagulation process, using FeCl 3 , Al 2 (SO 4 ) 3 and aluminum polychloride (PAC) coagulant in the coagulation process. In addition to these, an anionic polymer (Magnafloc) was also used. During the test the coagulation / flocculation carried out in Jar test, the best results were obtained with the addition of FeCl 3 were achieved at a concentration of 300 mg/L at pH = 9.0, in the presence or absence of the concentration of Magnafloc 1.5 mg/L. Under these conditions gave a turbidity removal of 90% and 92.8%, and oil and grease 91.6% and 86.8 %. Already when using Al 2 (SO 4 ) 3 , the best results were achieved at a concentration of 300 mg/L at pH = 9.0, also in the presence or absence of Magnafloc polymer at a concentration of 1.0 mg/L. In these tests the removal of turbidity was 93.5 % and 97.3 %, while that of oil and grease was 91.5 % and 93.3%. By adding the PAC in a concentration of 150 mg/L and equal to the value of pH 8.0 with and without addition of Magnafloc concentration of 1.0 mg/L, the results were 96.5% and 98.2% turbidity removal and 91.2% and 95% removal of oil and grease. After conducting all the tests, it was concluded that for this particular type of effluent, the PAC (150 mg/L) at pH 8.0 and in the presence of anionic polymer Magnafloc (1.0 mg/L) are presented as the best choice for the tr...

O presente estudo apresenta dois diferentes cenários de aproveitamento energético dos Resíduos Sólidos Urbanos (RSU),para o Município de Nova Iguaçu. O “Cenário I” contempla o ganho energético, proveniente do metano gerado do aterramento de 100% dos RSU, gerado na localidade. Já o “Cenário II” estima o ganho energético com a reciclagem de materiais como papel/papelão, plástico, metal e vidro, que geralmente, são depositados no aterro, e do metano gerado proveniente da fração orgânica do RSU, deste município. A quantidade de energia elétrica gerada do metano proveniente do aterro, mais a energia elétrica conservada levando em conta os índices de Morris proveniente da reciclagem, ambos do Cenário II corresponderam a um ganho energético de 5.633 MWh dia-1, aproximadamente 64%, maior que a quantidadede energia elétrica gerada, somente do metano proveniente do aterro no Cenário I, que corresponde a 2.034 MWh dia-1.

Avaliação de concreto sustentável contendo teores de resíduos de agregados reciclados Evaluation of sustainable concrete containing contents of recycled aggregate residues