Revista Brasileira de Ciência, Tecnologia e Inovação

Assessing the degradability of biodegradable-packaging base material through the insertion of organic solid waste deriving from composting process

Marcos Vinícius da Luz — 2024-08-27

The intensification of the use of plastic materials in recent decades has caused several environmental impacts, becoming direct incentives for research and development of alternatives that minimize the massive amount of plastics used by societies. In this context, so-called biodegradable materials emerge, with emphasis on starch-based compounds, which, although they have limited mechanical properties and low water resistance, allow the mixture with various reinforcing agents, in order to overcome the deficiencies for their application in larger scales without detracting from its focus on biodegradability. In this sense, the present study aimed to evaluate the biodegradability of a starch-based biopolymer, with the addition of different proportions of malt bagasse, this residue from the production process of beer; evaluating and monitoring parameters of the composting process of this mixture with organic solid waste. Biodegradation was determined from the visual assessment of the material, monitoring parameters such as pH, temperature, humidity and organic matter, being recorded in an electronic spreadsheet for descriptive analysis. The results obtained, when compared to the control composting unit, indicate a lower biological activity on the compost, consequently, a greater resistance to biodegradation. After three weeks of composting, it was difficult to identify the material and after four weeks, it was not possible to identify the biopolymer, indicating its biodegradation and incorporation into the substrate. It was observed that the material showed changes in its mechanical properties during composting. It is concluded that the material is totally biodegradable in all malt bagasse compositions, under composting conditions.

Iron and Manganese Removal through Adsortive Filtration based on Zeolites, at bank scale

Henrique Azevedo Silveira — 2024-08-27

The aim of the current study is to assess iron and manganese removal from water used for public supply through adsorptive filtration based on natural zeolites that were chemically prepared for metal removal purposes. The research was conducted at bench scale by using water samples from two water sources in Parana State. Full cycle studies were carried out; according to them, filtration was conducted, in separate, under four filter bed conditions, namely: sand, anthracite coal, zeolite without previous chlorine application and zeolite with previous chlorine application. The zeolite filtration test without previous chlorine application recorded high meaniron and manganese removal values, - 100% and 87.96%, respectively. Based on the filtration results, the zeolite filter without previous chlorine application was the best filter media among the tested beds, under the herein proposed conditions.

Changing cellulose acetate deriving from cigarette filters to be used as catalyst in effluent treatment

Emilly Giacobbo — 2024-08-27

Cigarette butts are a significant environmental issue, mainly when they are improperly discarded. However, this waste type is recyclable, since its structure is based on cellulose acetate, which is used in the industrial sector for absorbent and filtering purposes. The aim of the present study is to chemically change cellulose acetate deriving from cigarette filters by incorporating iron to it, in order to use it as catalyst in effluent treatment processes. Three different methods were used for iron immobilization purposes in basic, acidic and ferric media, for 7 days. The method showing the best iron adsorption, based on spectroscopic analyses, was the one wherein cigarette butts remained in contact with 0.1 mol/L ferric solution. Therefore, the group of cigarette butts resulting from this method was used in Fenton and photo-Fenton processes. Moreover, it recorded positive results for textile dye mix discoloration, as evidenced by spectral changes in the 350-700 nm range, which pointed out significant color change in the assessed sample. Although the current article results from a preliminary study, the herein collected data point towards the potential use of cigarette butts as alternative to treat effluents deriving from companies that use large amounts of dye.

Assessing soil compaction in sites subjected to different management systems

Emilly Giacobbo — 2024-08-27

Soil physical, chemical and biological quality is under constant change in rural areas, mainly in small farms where family farming prevails. Land use in these properties is maximized to ensure profitability. The aim of the current study is to investigate how different land-use types affect soil compaction in a small farm in Southeastern Paraná State. The herein investigated land-use types comprised forest, pasture, yerba mate cultivation, eucalyptus reforestation, no-till and conventional tillage. Soil density, resistance, porosity and moisture were the analyzed variables. The current findings enabled concluding that pressure deriving from different land uses affected soil compaction. Pasture recorded the highest soil compaction indices, whereas forest recorded the best indices for this variable. On the other hand, different soil management practices did not significantly affect soil density and porosity in agriculture. However, there were significant variations in soil moisture and resistance.

Toxicity standards of biosolid leachate

Rafael Lucas Alexandre — 2024-08-27

Sewage treatment in Brazilian cities generates biosolids that can be useful in the agricultural field, although they pose contamination risks to the environment and to human health. Ecotoxicity tests are essential to ensure the safety of such a use, since they assess biosolids’ toxicity in the soil and in water. The aim of the current study is to assess biosolids leachate phytotoxicity by using lettuce seeds. In order to do so, Petri dishes were used to incubate the seeds, which received the biosolids leachate and remained under controlled temperature conditions, in the dark, for 168 hours. Overall, the herein assessed parameters have evidenced that the biosolids leachate diluted up to 60% had positive effect on (i.e., it stimulated) seedling growth and germination. However, phytotoxic effect was observed when it was applied without any dilution, since it reduced seed germination and growth parameters. Therefore, the lower the leachate concentration, the higher the Lactuca sativa root growth, a fact that highlights the phytotoxic effect of this leachate.

Analysis of land use change after the Brumadinho tragedy and its legal implications

Barbara Rente Barbosa — 2024-08-27

On January 25, 2019, the “Barragem I” in Brumadinho, state of Minas Gerais, caused significant socio-environmental damage when it burst. 665 victims were identified, with 270 deaths, and unprecedented environmental impacts in the watershed. In this study, we assess land use and land cover changes following the dam damage and the legal implications of these changes. The results show that the tailings extended over 306.95 hectares, burying approximately 98 buildings. Of this area, 45.9% was occupied by native vegetation, 22.19% by agricultural activities, and 2.5% by urban areas. The event caused irreversible impacts on the water quality of the Paraopeba River, decimating ecosystems, leading to socioeconomic destabilization of the region and violating legal environmental requirements. Principles and laws clarify that the principle of prevention, human dignity, and the laws of the National Policy on Dam Safety, the Federal Constitution, and the National Environmental Policy were violated.

Rainfall analysis in Xingu River Basin based on the 1981-2020 timeframe

João Batista Marcelo de Lima — 2024-08-27

It is essential understanding the incidence of hydrometeorological variables in each river basin to help planning actions focused on guaranteeing multiple water uses, environmental preservation and prevention measures taken against extreme events. The aim of the current study is to investigate rainfall trends in Xingu River Hydrographic Basin (XRHB) from 1981 to 2020. Data propensity analysis was carried out based on the Mann-Kendall methods, on five-year moving average graph, as well as on variations in Climatological Normals (CN) recorded from 1981 to 2010 and from 1991 to 2020. Moreover, the Log-Normal theoretical distribution was adjusted to show mean rainfall predictions within 10-to-100-year return time (Rt). It was done by applying the Kolmogorov-Smirnov (KS), Chi-Square (?²), Filliben (Fi) and Anderson-Darling (AD) tests. Results have evidenced historical series with no trend and minimal variation (-0.5%) between the two CN intervals. Estimates within a 10-to-100-year RT scenario have evidenced rainfall rates higher than the historical average (HA) ranging from 10.0% to 20.0%. Thus, XRHB is a promising scenario for water security planning purposes, since it meets the fundamentals of Brazilian environmental and water resources laws, as well as target 6.5 of Sustainable Development Goal 6 (SDG 6 - UN), which deals with implementing integrated water-resources management at global level.

Analysis of TELEVALE’s wireless sound alert system: technological innovation approach applied to self-rescue zones of dams

Pedro Flávio Dias Portela Oliveira — 2024-08-27

: Na atualidade, com o crescente número de usinas localizadas próximas a zonas habitáveis, houve a necessidade de conter os riscos e seus fatores, que podem desencadear rupturas nas barragens, colocando a população em perigo próxima às áreas a jusante, frente a um possível desastre ambiental. Este estudo teve como objetivo avaliar a implementação de um sistema de alerta sonoros de alta potência desenvolvido para notificação emergencial de evacuação da população em massa de moradores próximos a barragens da Usina do Rio do Peixe. Para tanto, na pesquisa de campo, inicialmente a Usina Rio do Peixe enviou dados sob a forma de mapeamento prévio da Zona de Autossalvamento (ZAS). Posteriormente, foram instaladas as Estações Remotas em pontos estratégicos definidos pela Usina, seguidas das simulações a campo aberto, para validar o nível de pressão sonora de no mínimo de 70 dB. Os resultados apontam que o SNE-T é eficaz, seguro e confiável, considerando que todas as três medições foram acima de 70 dB, atendendo as exigências da Política Nacional de Segurança de Barragens. Importante relatar que pelo sucesso do SNE-T, o pesquisador e a TELEVALE foram premiados, em 2022, com o Prêmio Nacional de Inovação, referendado, pelos aspectos técnicos, acústicos e tecnológicos, bem como pelo baixo custo de produção e implantação, uma vez que o SNE-T é de desenvolvimento 100% nacional. Infere-se que a tecnologia inovadora do sistema de alerta emergencial, analisado nesta pesquisa, é confiável, eficaz e seguro, além de ser financeiramente viável.

Optimized sizing of a pumping system using the Scilab software

Natália Vernillo — 2024-08-27

Climate change represents, today, one of the greatest challenges regarding the availability of water resources for the cultivation of food and raw materials of plant origin that the world's population so badly needs. Sugarcane, due to its high added value to produce several products and whose accumulation of sucrose is mainly due to a perfect dosage of water, brought to light the need to obtain new irrigation strategies, thus aiming at a more sustainable, efficient and economical management of water consumption in this sector. As an alternative to this challenge, drip irrigation stood out, which allowed not only a more precise control of water dosage, but also essential nutrients for the development of sugarcane. Taking advantage of this, a sugar and alcohol plant in the interior of the state of São Paulo, whose identity will be preserved, made several investments to implement this system on its farms and one of these projects will be discussed in detail about the dimensioning of the entire piping network. which involves the pumping system, from water collection to discharge into a storage tank, responsible for supplying the dripping, using a pre-dimensioned pump and respecting the specifications defined by the client for this work. In addition, the free software Scilab was used to implement the piping and pumping sizing procedure, as an extra tool, in addition to development in Excel.

Using biosensors for the early diagnosis of arboviruses: a scoping review

Lígia Marques Vicente — 2024-08-27

Mapping scientific knowledge about the development of biosensors to be used for the early diagnosis of arboviruses. Scoping review based on studies searched in Lilacs, PubMed, SciELO and Web of Science databases. Nineteen (19) articles were selected, in total. The selected studies presented different types of biosensors used to detect arboviruses and their variants, with emphasis on dengue and Zika viruses. Electrochemical, optical and plasmon resonance were the biosensors mostly used for the aforementioned purpose due to their little margin of error. They enable reliable and fast diagnosis processes, besides being easy to handle and its low cost. Biosensors capable of identifying arboviruses are not yet available in health services, since they still require advancements to be achieved at practical research stages.