Navegando por CNPq "CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA::SANEAMENTO AMBIENTAL::RECICLAGEM DE RESIDUOS SOLIDOS"

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Acesso aberto (Open Access)
Influência da sílica e da temperatura nas propriedades físicas dos agregados sintéticos produzidos com resíduo do processo bayer
(Universidade Federal do Pará, 2019-03-21) SANTOS, Diego Hildebrando dos; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
The use of waste from the mining and metallurgy industry has become indispensable, so that this industrial segment is inserted in the concept of sustainable development. The work shows an application for red mud that, in combination with other materials such as silica and clay, produces a material with mechanical resistance and specific mass, which can be compared to the natural aggregates used by the civil construction industry. In the work all the raw materials and the final sintered product were submitted to x-ray diffraction analysis, scanning electron microscopy. Red mud and clay were also analyzed by x-ray fluorescence. The synthetic aggregates were produced with the intention of studying the relationship between the amount of silica used and the apparent specific mass, which had satisfactory results on sintered specimens at 1300 ° C, obtaining heavy aggregates with 10% silica and aggregates with values below 2 g/cm3 with 20% and 30% silica samples, characterizing so the aggregate as light. Therefore, the silica content, the amount of clay used together with the oxides present in the red mud, together with the ideal granulometry of these materials and the temperature, form a glassy phase that will give the aggregates important characteristics such as porosity, mechanical strength and apparent specific mass.
Acesso aberto (Open Access)
Influência do uso de resíduos industriais nas propriedades mecânicas e reológicas de argamassas utilizadas na indústria da construção civil
(Universidade Federal do Pará, 2019-03-21) CARDOSO, Dilson Nazareno Pereira; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/1711061955509303
The general objective of this work was to develop alternative and usable materials within the construction industry, addressing a logic of recovery and reuse of solid waste, generated from construction and demolition construction sites, as well as the reuse of waste generated from the construction industry mining industry and mineral processing. Were used in the work the residue of construction (RCC), residue of sulfide copper ore (RMCS) and the waste of circulating fluidized bed boilers from the combustion of coal to fly ash (CV). The samples of these materials showed appropriate characteristics, such as recycled fine aggregate within the NBR 7211 standard. The materials were subjected to physical and chemical characterization through laser particle size analysis, x-ray fluorescence (FRX), diffraction and x-ray (DRX).). The mortars produced were studied in the free state, that is, without additives and also within the insertion of polymeric organic additive polyvinyl acetate (PVA) and Styrene Butadiene (SBR). The obtained mortars were physically characterized through the analysis of apparent porosity, water absorption, apparent specific mass and resistance to axial compression. Thermal analyzes of (TG and DTG) and scanning electron microscopy - SEM were also performed. In the fluid state rheological tests were performed to evaluate its behavior according to time (thixotropy), workability and the most representative rheological model for its flow. The developed materials presented technical properties approved by the ABNT standards, making them suitable for certain types of applications, in terms of laying and covering of walls, floors and ceramic tiles, respecting the technical characteristics of these materials.
Acesso aberto (Open Access)
Reciclagem como alternativa para a eficiência e sustentabilidade econômica do setor de resíduos sólidos urbanos no município de Belém-PA
(Universidade Federal do Pará, 2018-05-28) SANJAD, Heitor Capela; PEREIRA, José Almir Rodrigues; http://lattes.cnpq.br/9918600634569244
In the research, classified as descriptive and exploratory, the technical efficiency and economic sustainability of the solid urban waste (SUW) sector of the city of Belém - PA was evaluated. The research divided into three stages had in its first phase the execution of the legal, operational and financial diagnosis of the municipality. Then, in the second stage, scenarios were established to recycle 10%, 25% and 50% of MSW generated in the municipality in the year 2017. In the last stage, the sales prices of recyclables were determined and the economic prospects were estimated in the proposed scenarios, besides the evaluation of the financial benefit that the selective collection can bring the public finances. The generation of 340,405.39 tons SUW was verified in the city of Belém, as well as the existing need to update the laws, elaboration of the planning tools and reformulation of the forms of collection of the services provided in the sector. It was also observed that the implementation of recycling of 10%, 25% and 50% of the total RSU mass generated in 2017 would reduce operating expenses by R $ 11,302,703.66, R $ 8,256,759.16 and R $ 56,513,518.32, respectively, in the proposed scenarios. With the work it was possible to conclude that recycling is an excellent alternative to improve infrastructure and reduce expenses in the SUW sector of the municipality of Belém.
Acesso aberto (Open Access)
Resíduos de gesso na construção civil: uma análise bibliométrica na base de dados eletrônica Web of Science
(Universidade Federal do Pará, 2021-11-05) FREITAS, Pablo Virgolino; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
The construction sector stands out for the exploitation of natural resources and for the production of residues that, in the vast majority, are improperly discarded in nature, generating serious negative consequences for the environment. Aiming to minimize the harm caused by the poor disposal of Construction and Demolition Waste - CDW, as well as to develop alternative ways to replace natural raw material by recycled waste, many studies have been carried out. Among the materials that have high recycling potential is gypsum, whose residues are already being used as a binder, additives in Portland cement, soil correction, among other forms of recycling. Therefore, this study aims to analyze Brazilian and international scientific publications dealing with the reuse of plaster in civil construction, performing a bibliometric mapping in the Web of Science electronic database. The mapping was carried out through exploratory research related to the reuse of gypsum waste in several scientific articles. Words and expressions that had the highest frequency of occurrence in published articles were collected. The search in the database resulted in 89 articles, of which 42 contained information on the recycling of gypsum waste in civil construction. The selected articles belong to authors from 19 countries, the most representative being Brazil, with 13 articles. Through the VOSviewer software, network maps were elaborated, through which it is demonstrated how authors and scientific institutions relate in relation to the recycling of plaster waste. The results of the articles studied here compose a portfolio through which effective methods of reusing this waste can be verified, thus facilitating the search by third parties for this type of information. What can help in the formulation of public mechanisms that help to improve solid waste management in Brazil, because, through the social network Instagram, this information will be made available in order to reach an audience that goes beyond academic borders.
Acesso aberto (Open Access)
Utilização de tecidos de fibras de bananeira como agente de reforço em compósitos de matriz de resina poliéster termorrígida
(Universidade Federal do Pará, 2023-08-11) BAÍA, Michele da Costa; EL BANNA, Wassim Raja; http://lattes.cnpq.br/2005046563115507; https://orcid.org/0000-0001-5085-4352
In recent decades, several studies have been observed, both nationally and internationally, which seek alternative materials to those conventionally used by industry, with emphasis on biomass residues from agricultural activities, such as vegetable fibers, in the quest to minimize the problems caused to the environment and replace products harmful to human beings. In addition to offering advantages such as atoxicity, biodegradability, low density and reduced cost, such as fibers derived from the pseudostem of the banana tree. With regard to banana trees, Brazil is one of the largest producers of its fruit at an international level, and as a result this is one of the activities that most generate waste in the country. Therefore, this research has as main objective to make composite materials with the fibers of the pseudostem of the banana tree in the form of fabrics and thermoset polyester resin, destined to the production of materials for engineering. Initially, the process of extracting and cleaning the fibers was carried out, followed by the weaving of flat-type fabrics on the nail loom, to be used as a reinforcing agent. Next, polymeric composites were molded using a manual process (hand lay up) and application of pressure at room temperature. Thus, composites were obtained: full matrix and those reinforced with glass fibers and banana tree fibers. Mechanical tests were carried out – flexion and traction –, flammability and microscopy. The polymeric composites were manufactured in the following compositions: V1 – Full matrix; V2 – with reinforcing agent with two layers of fiberglass mats; V3 – with reinforcing agent with one layer of banana fiber fabric and V4 – with reinforcing agent with two layers of banana fiber fabric. The materials of composition V3 and V4 presented tensile strength values of 29.25 MPa 51.27 MPa and bending strength of 142.45 MPa and 91.99 MPa, respectively. As for resistance to flammability, all composite materials manufactured showed values below those stipulated by the regulations and within the Brazilian standard. The analysis of the failure mechanisms present on their surfaces was performed using MEV, which can show the arrangement between matrix and reinforcing agent, as well as the presence of cracks in the matrix, fracture and rupture of fibers in the reinforcing agent, voids and pullout.