http://bdtd.uftm.edu.br/handle/tede/624 Tue, 21 Apr 2026 01:35:40 GMT 2026-04-21T01:35:40Z http://bdtd.uftm.edu.br/handle/123456789/1949 Título: Estudo dos efeitos alelopáticos de extratos obtidos de Eucalipto (Eucalyptus sp) em culturas de alface (Lactuca sativa L) Abstract: Allelopathy studies the interactions between plants through the release of secondary metabolites into the cultivation medium, which interact with other plant species and can cause beneficial effects such as increased protection of aerial parts against the incidence of insects, or harmful effects such as growth interruption. . These effects are observed in agroforestry systems; however, it has become the object of study for the possibility of developing molecules as an aggregate in the production of agricultural pesticides or direct use as lower impact management. The present work aims to identify chemical substances capable of causing allelopathic effects through qualitative mechanisms using chemical reactions and test the effects of allelochemicals on lettuce seedlings. The parts of the Eucalyptus plant were purchased from local stores in Uberaba-MG and were washed, dried and calculated for humidity. The extraction and identification of classes of chemical compounds was carried out through chemical reactions. Furthermore, solutions containing allelopathic substances were prepared and applied to lettuce seedlings in a randomized block design. Plant size was measured on the sixth day after applying the solutions to the plants. The results were compared using ANOVA and Tukey test at 5% significance. Through the reactions, the presence of several classes of substances was identified, such as: flavonoids, alkaloids, phenanthrenes and tannins in large percentages of the tests. These substances influenced both the growth and development of seedlings, generating effects in parts of the blocks. Thus, the results show that these substances generate effects on these plant species and can be used as a form of management with less impact and production of assets and products that are less aggressive to the environment. Tipo: Dissertação Thu, 14 Dec 2023 00:00:00 GMT http://bdtd.uftm.edu.br/handle/123456789/1949 2023-12-14T00:00:00Z http://bdtd.uftm.edu.br/handle/123456789/1946 Título: Eletrodo de ouro como sensor eletroquímico para monitoramento de chumbo em águas naturais para abastecimento público Abstract: Potentially toxic metals could bioaccumulate in body tissues of living organisms and can cause toxicological effects on soil properties and human and animal health. There are several methodologies available for the quantification of metals in aqueous matrices. However, these techniques become expensive due to the high cost and the need for specialized professionals to handle the equipment. Therefore, the objective of this work was the application of the gold electrode (EAu) without modifications on its surface in order to analyze the presence of Pb2+ ions in surface waters of Córrego Lanoso in Uberaba - MG, through anodic stripping voltammetry, without the need for sample preparation. The voltammetric parameters were optimized with the aid of the Rotational Central Composite Design (DCCR) and the validation of the method was performed using an atomic emission spectrophotometer (MP-AES 4200 Agilent). The analyzes using the electrochemical sensor showed limits of detection (LD) of 0.04 ng L-1 and limit of quantification (LQ) of 0.13 ng L-1. Furthermore, lead levels were found in the real sample, evidencing the effectiveness of using the EAu without modifications, to detect Pb2+ ions in natural waters (public supply). In short, this methodology proved effective in quantifying Pb2+ ions in concentration in the environment, easy handling, real-time analysis, without the need for sample preparation, leaving only economic feasibility studies for the commercial implementation of the aforementioned electrochemical sensor. Tipo: Dissertação Wed, 30 Aug 2023 00:00:00 GMT http://bdtd.uftm.edu.br/handle/123456789/1946 2023-08-30T00:00:00Z http://bdtd.uftm.edu.br/handle/123456789/1945 Título: Desafios e avanços na degradação biológica de plásticos: uma revisão sistemática integrativa Abstract: Currently, polymers are widely used in various sectors, including consumer and industrial applications, playing an essential role in everyday human life. Since the early 20th century, research involving polymeric materials, both synthetic and natural, has expanded knowledge about their properties, driving technological advancements and revealing a wide range of applications for this type of material. However, the high consumption of synthetic polymers generates large amounts of waste, with low recycling rates and significant environmental impact. Global initiatives and the promotion of sustainable practices seek solutions to mitigate these effects, highlighting the importance of environmental education and the development of biodegradable materials. The biodegradation of plastics presents itself as a promising alternative, with research focused on accelerating their decomposition to reduce pollution and promote sustainability. This study addresses the challenges and advances in the biological degradation of plastics through a systematic integrative review, analyzing techniques and methods related to the action of microorganisms and specific enzymes within the time frame of 2015 to 2023. Data were collected from the Scopus and Web of Science databases, using the keywords "Degradation," "Plastic," and "Microbial" in studies conducted in China, the United States, and Brazil. The research also included a search for patents filed with the National Institute of Industrial Property (INPI). The findings reveal a growing academic and technological interest in sustainable solutions, highlighting the potential of bacteria, fungi, and yeasts in the decomposition of widely used polymers such as PET, PE, and PS. The analyzed studies also indicate that microbial consortia and enzymes promote the depolymerization and mineralization of waste. However, challenges persist for the practical application of biodegradation, such as the need for pretreatments and process adaptation on a large scale. On the other hand, the use of biodegradable plastics, which decompose more rapidly when combined with microbial action, also proves to be a promising approach, promoting pollution reduction and greater economic circularity. The study concludes that investments in research and public policies are essential to transform waste management and foster the development of viable biotechnological technologies. Tipo: Dissertação Wed, 27 Nov 2024 00:00:00 GMT http://bdtd.uftm.edu.br/handle/123456789/1945 2024-11-27T00:00:00Z http://bdtd.uftm.edu.br/handle/123456789/1944 Título: Avaliação da qualidade do ar em área rural de Uberaba-MG Abstract: Air pollution has emerged as a global environmental problem that threatens human health, causing millions of deaths and decreasing the quality of life of people every year. In this context, this study aimed to assess air quality in relation to the potential impact on respiratory health within a rural school community in Uberaba-MG. To achieve this, the concentration of particulate matter (PM10) and the composition of total suspended particles (TSP) concerning the presence of potentially toxic elements (PTE) and microplastics were monitored at the school (point A) and at two other locations in the central urban area (point B) and the peripheral area of the municipality (point C). Health data were obtained through a questionnaire administered to the staff of the rural school. Environmental data were subjected to ANOVA and comparisons of unequal means using the Tukey test. Respiratory health data were analyzed and discussed according to Bardin’s content analysis. The highest concentrations of PM10 were recorded at point A, which reached a maximum of 159.32 μg/m³ over a 24-hour period, corresponding to “very poor” air quality. At point C, most concentrations were higher than 50 μg/m³, while point B had values corresponding to good air quality. The daily standard (120 μg/m³) was exceeded at points A and C. The metallic elements lead (Pb) and iron (Fe) were identified in TSP samples from all three points. Point A showed the highest concentration of Fe and was the only location to record the presence of cadmium (Cd). Fourier-transform infrared spectroscopy identified the presence of: polystyrene (PS); polyethylene terephthalate (PET); polyethylene (PE); polypropylene (PP); polymethyl methacrylate (PMMA); and nylon. The questionnaires highlighted the presence of respiratory diseases and symptoms among the staff at the rural school, characterizing the air quality at the workplace as poor or very poor, especially during winter. This research provides important technical-scientific information regarding the concentration of inhalable particles, PTEs, and microplastics associated with particulate matter and their impacts on the respiratory health of the community. It is hoped that this study will contribute to the implementation of public policies aimed at improving the quality of life for the population. Tipo: Dissertação Wed, 31 Jul 2024 00:00:00 GMT http://bdtd.uftm.edu.br/handle/123456789/1944 2024-07-31T00:00:00Z