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:No presente trabalho é estudado o preparo de membranas anisotrópicas compostas, em uma única etapa, para os processos de NF e OI, através do espalhamento simultâneo de duas soluções poliméricas [acetato de celulose -AC/formamida/acetona (26,3/23,7/50 % p/p) e AC/poli(vinil pirrolidona) -PVP/N,Ndimetilformamida -DMF (15/10/75 % p/p)]. A precipitação das soluções, em água destilada, foi acompanhada por medidas de transmitância de luz. Estudou-se a influência das condições de preparo das membranas, na sua morfologia e nas suas propriedades de transporte (fluxo de permeado e retenção de solutos -Polietilenoglicol (PEG) para a NF e NaCl para a OI). Realizou-se também um tratamento térmico nas diferentes membranas produzidas. Os resultados mostraram que é possível obter membranas celulósicas com total aderência das diferentes camadas, a qual pode ser atribuída às condições de transferência de massa que retardam a precipitação na região próxima à interface das soluções espalhadas simultaneamente. Com relação aos testes de OI e NF, as membranas desenvolvidas apresentaram valores de fluxo permeado (7 -465 L/h.m 2 ) dentro da faixa das membranas comerciais, retenção salina (NaCl) entre 24-63 % e retenção do PEG entre 53-82 %, mostrando o potencial de aplicação destas membranas. Palavras-chave: Acetato de celulose, osmose inversa, nanofiltração, processo de inversão de fases, espalhamento duplo. Membranes for Nanofiltration and Reverse Osmosis Prepared by Simultaneous Casting of Two Polymer Solutions.Abstract: The purpose of this work is to investigate the preparation of composite anisotropic membranes in a single stage, through the technique of simultaneous casting of two polymer solutions (cellulose acetate (CA)/ acetone/formamide (26.3/50/23.7 % w/w) and CA/polyvinylpyrrolidone/dimethyl formamide (15/10/75 % w/w)). The precipitation of the solutions was followed using light transmission experiments. The effect of the exposition period precipitation bath on the membrane properties is also reported. All the membranes were characterized by scanning electron microscopy and by permeation experiments. The RO and NF experiments are carried out using 5,000 µg/g (ppm) of NaCl aqueous solution and 5 g/L of polyethyleneglycol (PEG), 6 KDa, aqueous solution, respectively. Moreover, to reduce defects in the upper layer, the membranes were immersed in a water bath at 90°C for 60 minutes. The membrane morphology analysis indicates that is possible to obtain complete adhesion of the two layers. This result is related to the mass transfer conditions, which should delay the precipitation in the regions near the polymer solutions interface. Regarding the performance of the membranes in RO and NF experiments, the permeate fluxes are comparable to those observed with commercial membranes (7-465 L/h.m 2 ). The solute retention varied in the range of 24 to 63% for NaCl, and in the range of 53 to 82% for PEG. These results point out the potential of technical scale application of the double layer membranes.

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Elaborado por Maurício Amormino Júnior-CRB6/2422 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. 2019 Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.

With a generation of more than 2 million metric tons per year, Brazil is the largest producer of waste electrical and electronic equipment in Latin America. However, Brazil does not have its own way for treating printed circuit boards, a key component present in this type of waste. In this context, the processing of these components would allow the extraction of metals with high added value, mainly copper, silver, gold, and palladium. The purpose of this research is to design a conceptual treatment route, based on the integration of technologies described in the literature. After creating the route design, a mass and energy balances were performed, considering two printed circuit board source as raw material: (Case A) Wasted equipment in general; (Case B) Using only cell phones. For both cases, the treatment of 2 t·h−1 was considered. In addition, cost estimates and plant sensitivity analysis were carried out. For 15 years of plant production, the calculated Capex was USD 2,002,682, where an internal return rate of 140.1% and 3933.0% was obtained for Case A and B, respectively, and a net present value of USD 44,403,373 and USD 3,210,393,496 for Case A and B, respectively. Additionally, it was observed that Case A has a great sensitivity to the variation of the processing volume. Based on the present findings, this theoretical research has the potential to be a nucleation point in the design of a future industrial plant dedicated to the recycling of printed circuit boards, as well as to understand the key variables for the processing these components, based on Brazilian circumstances. Additionally, the project presents the hypothetical investment required for the creation of such conceptual plant, which is a crucial piece of information for potential investors.