Revista Brasileira de Ciências Ambientais

Phenomenological subjectivity and consciousness – groundwork for an eco-phenomenology

2024-10-26T22:01:33-03:00

The present research aim to analyze the foundations of Husserl’s phenomenology and its legacy, employing its attributes in the creation of an eco-phenomenology toolset. The trend in question focuses on the notable revision of the subject-object relationship, introduced by Husserlian thought. From his repositioning of the reflective subject under the transcendental ego, Husserl authorizes the reconstitution of the cognitive and epistemological bases of thought on a set of entitative qualities, which equates the aware observer to the observed entitative universe, according to the similarity of existential conditions. Thus, the reflective character that sediments human experience is henceforth considered a natural phenomenon, contiguous to other transformations and determinations of meaning conferred by non-human beings—biotic and abiotic, demanding a re-conception of their phenomenological roles as semiotic agents (and, therefore, agents of environmental transformation). The perspective changes translated here provide us with an opportunity to approach and refine the proposal for an assembly (parliament) of non-humans presented in Latour’s work, thereby insinuating that the establishment of an ecocentric paradigm will only be possible under such philosophical conditions. Based on the massive version of this paradigm, the purpose is to review the scientific and political fundamentals for organizing the political scenario in favor of so-called ecological democracies.

Numerical method for carbon footprint assessment of recycled concrete aggregates

2025-03-13T15:50:27-03:00

The construction sector is a major generator of atmospheric emissions and solid waste, denoting the need to account for its environmental impacts in contributing to climate change. One way to analyze these effects of the sector on the environment is through life cycle assessment (LCA), which considers the impacts of the entire product system. This research proposed a numerical method for the LCA of recycled concrete aggregate (RCA), related to carbon footprint, based on the procedures of NBR ISO 14040, using databases and other studies as references for modeling. This meets the need to simplify the LCA of the RCA determination process, given the complexity of material characteristics data, offering a practical alternative for academic and industrial applications. In the model, three main processes were adopted: concrete structure demolition, material transportation, and aggregate recycling; they were classified and quantified based on emissions from the use of electrical energy and the burning of fossil fuel. Thus, the LCA equation was modeled according to the final size of the aggregate and transport distances, making it possible to obtain a carbon footprint value. In the end, it was possible to conclude that the complete model was able to simplify the implementation of LCA in RCA, obtaining statistical consistency and reliability through validation with reference studies.

Evaluation of a novel seriguela gum (Spondias purpurea L.) based flocculant aid for wastewater treatment: effect of carboxymethylation

2025-03-12T03:45:09-03:00

Seriguela gum is a barely explored polysaccharide, whose carboxymethylation reaction can expand its applications for water treatment by the increase of negative charges in the chain. Thiswork aimed to produce carboxymethyl derivatives, under different reaction condition, to apply as a flocculation aid in water treatment. Thederivatives were characterized by titration, Fourier transform infrared spectroscopy, nuclear magnetic resonance, and gel permeation chromatography techniques. The reaction condition parameters, sodium hydroxide concentration, and chloroacetic acid molar ratio significantly affected the degree of substitution, with values between 0.35 and 0.51. Optimal results were achieved using lower concentrations of sodium hydroxide and intermediate chloroacetic acid levels. The derivative produced with higher degree of substitution was used as flocculation aid combined with aluminum sulfate for the treatment of contaminated river water. The tests demonstrated that the use of 3 mg/L of carboxymethylated seriguela gum combined with 20 mg/L of aluminum sulfate removed 93.1% of turbidity, showing a 21.0% increase in efficiency and a 60.0% reduction in the use of aluminum sulfate alone. It also exhibited low toxicity to Artemia salinaat high concentrations (100 mg/L) due to its biocompatibility. The study revealed that carboxymethylated seriguela gum with increased negative charges can be obtained with a high degree of substitution by a simple and high-yield process, and the tests showed high potential for application as a flocculation aid in water treatment processes.

Microplastics and particulate matter: assessment of atmospheric pollution in the Region of Hortênsias, Brazil

2025-02-24T13:18:41-03:00

Atmospheric pollution is one of the main consequences of anthropogenic activities in the environment. The insertion of particles suspended in the air, which are composed of dust, fumes, microplastics, and aerosols emitted by industries, vehicles, and constructions, alters the quality of the environment they are inserted into, impacting both human health and the environment. Therefore, this study aimed to identify the atmospheric particles that may influence the air quality in the Region of Hortênsias (municipalities of Canela and Gramado) in Rio Grande do Sul state. The concentrations of the particulate matter PM_2.5 and PM_2.5-10 were evaluated at two sites from April 2021 to April 2022. The fine and coarse particulate matter sampler (FCS) was used to collect samples at the site located in Canela. In Gramado, besides the FCS, a dichotomous sampler was also used. The filters were observed under a microscope to evaluate the presence of polymeric material. The selected particles were then analyzed by scanning electron microscopy (SEM) coupled with energy-dispersive x-ray spectroscopy (EDS). Six samples of PM_2.5 did not meet the air quality standards recommended by the World Health Organization guideline. The results demonstrated low air quality, and the microscopic analysis detected the presence of particles with polymeric material characteristics. These particles suggest traces of microplastics, in addition to the presence of vehicular soot and fly ash when analyzed by SEM/EDS.

Assessing the drought in the state of Ceará - Brazil: the relationship between drought, trophic state index, and anthropogenic pressure

2025-02-04T09:19:27-03:00

The present study addressed the effects of water scarcity on the deterioration of water quality in 155 reservoirs located in the state of Ceará, Brazil, using the drought index SPI (standardized precipitation index) calculated for the accumulation time scales of 3, 6, and 12 months. Based on this, a comparison was made with the variations in the trophic state index of these reservoirs, between 2008 and 2021. The study pointed to the occurrence of an intense series of dry events between 2012 and 2018, highlighting the year 2013, when the SPI assumed a value of -2.43 identifying an extremely dry year. Also, during this period, the amount of water stored by the state’s reservoirs achieved only 8% of the total storage capacity, with the existence of eutrophic and hyper-eutrophic dams accounting for 68% of the total in 2016. In this context, it was observed that, during the transition from a dry to a wet period, the average trophic state index of the reservoirs tended to increase, rising from 62.1 (2008–2012) to 65.1 (2013–2017), before decreasing to 61.5 with the return of the wet period (2018–2021). In addition, to assess the influence of human activities on water quality, land use and occupation data from three basins in Ceará were analyzed. It was observed that the basin with the largest area occupied by agriculture experienced the most significant increases in total phosphorus and chlorophyll-a concentrations.

Application of electroc hemical processes in aerobic biological systems used for textile wastewater treatment: effects on mixed liquor characteristics and pollutant removal

2025-02-27T09:56:29-03:00

This study evaluated the influence of electrochemical process application on pollutant removal and changes in the characteristics of mixed liquor in aerobic biological systems used for textile wastewater treatment. For this purpose, samples of mixed liquor containing synthetic textile wastewater (nitrogen, phosphorus, acetate, and Drimaren Red CL-7B dye) were introduced into bench-scale reactors operated under two experimental conditions: in the first condition, the application was performed with a current density of 20 A m⁻², using an intermittent exposure mode of 6 min on / 30 min off (Strategy 1 – S1), while in the second, the same current density was applied but under continuous exposure (Strategy 2 – S2). A control reactor was operated simultaneously for comparison purposes, evaluating pollutant removal and the filterability of the mixed liquor. The results indicated that electrochemical processes improved the filterability of the mixed liquor by 35% in S1 and 44% in S2. Dye removal ranged from 40 to 50% in the control reactor, reaching 67% in S1 and 93% in S2 with the application of electric current. Regarding phosphorus, the application of electric current increased removal from 30% in the control reactor to 67% in S1 and 96% in S2. No significant changes were identified in the content of total suspended solids with intermittent application. However, under continuous exposure, an increase of approximately 30% was observed. It was concluded that the application of electrochemical processes can be a promising alternative to enhance the performance and stability of biological treatment systems applied to textile wastewater treatment.

Post-consumer batteries: a case study of generation and formal disposal in the capital of Paraíba, Brazil

2025-02-17T20:26:28-03:00

Batteries, part of waste electrical and electronic equipment (WEEE), can contain heavy metals which, when disposed of inappropriately, cause damage to human health and the environment. Thus, this study aimed to identify the quantity generated and the disposal flow of post-consumer batteries in João Pessoa (capital of Paraíba), Brazil, to provide information that contributes to the reverse logistics system for this waste in the city. To this end, a mapping of the voluntary drop-off points (PEV) of batteries registered in the Green Eletron was carried out, with a simplified on-site checklist and data collection from a sample of 400 inhabitants, using an online form related to batteries consumed. The results showed that, of the PEV registered, only 19 had active collections, and of these, only 13 had a collector in a visible and easily accessible place. The majority of participants dispose of batteries in household garbage cans (62.6%), rate the provision of disposal information in establishments as poor (50.5%), are unaware of the existence of PEV in the city (67.3%), and are aware of the risks of incorrect disposal and the legal instruments available. However, they report that the lack of battery PEV would be one of the main difficulties for proper disposal; consequently, there are deficiencies in the current management of post-consumer batteries. Some suggestions for improvements to the success of reverse logistics are related to the installation of new PEV with homogeneous distribution and more significant publicity for existing points.

Life cycle assessment of a vapor absorption refrigeration system applied to a university building in Northeast Brazil

2025-02-07T07:34:01-03:00

Due to the increase in global warming and the growing demand for thermal comfort in tropical climate regions, refrigeration systems have become essential to ensure adequate conditions in residential, commercial, and institutional environments. At the same time, efforts are being made to reduce the environmental impacts associated with their use. In this context, the present study conducts a life cycle assessment (LCA) of a double-effect vapor absorption refrigeration system (SFAVDE) with a cooling capacity of 352 kW, using direct natural gas combustion as an energy source. The main objectives of this work are: i. to provide a life cycle assessment for SFAVDE technologies used to meet the cooling demand of a specific university building in Northeastern Brazil and ii. to perform a dominance analysis to identify the main contributors to environmental impacts in the SFAVDE. The LCA study was conducted using the ReCiPe endpoint method (humanitarian, average weighting – H/A). Simulations were performed using the open-source software openLCA version 1.10.3, utilizing the Ecoinvent 3.7.1 life cycle inventory database. The simulation results showed that, in the ecosystem, human health, and natural resources categories, the greatest environmental impacts were caused by climate change and ecosystems (17.19%), climate change and human health (27.18%), and fossil depletion and natural resources (43.70%). Regarding the dominance study, the results indicated that, for the transport and operation stages, the main impacts were air transport (91.00%) and natural gas usage (97.00%), respectively. In the disposal stage of the SFAVDE, copper recycling resulted in a 34.61% reduction in environmental impact compared to landfill disposal. Therefore, to mitigate the environmental impacts of the SFAVDE, it is recommendedto assess transportation alternatives, utilize renewable fuels during the operation phase, and prioritize the reuse of copper during the manufacturing and disposal stages.

Size-mass relationships of aquatic insects in forest streams: addressing a knowledge gap in Neotropical communities

2024-12-16T20:37:08-03:00

Determining individuals’ dry mass is crucial for better understanding community structure in terrestrial and aquatic ecosystems. The establishment of size–mass relationships for different populations constitutes a helpful tool for indirectly determining the total biomass of freshwater communities. In this study, we determined the size–mass relationships of 14 genera from the orders Ephemeroptera, Plecoptera, Trichoptera, and Odonata commonly found in leaf patches in Atlantic Forest streams (SE Brazil). We used individual body length as a size measure and three mathematical models (linear, exponential, and power) to establish the best-fitting equations. The equations described by the power model showed the best fit (coefficient of determination [r²]≥0.80) for the genera Anacroneuria, Macrogynoplax (Plecoptera), Smicridea (Trichoptera), Archaegomphus, Idiataphe, Hetaerina, Heteragrion, and Neocordulia (Odonata); the exponential model presented the best fit for Phylloicus (r²=0.74), Triplectides (Trichoptera, r²=0.60), Enderleina (r²=0.96), and Tupiperla (Plecoptera, r²=0.60); and the linear model exhibited the best fit for Elasmothemis (Odonata, r²=0.85) and Massartella (Ephemeroptera, r²=0.63). Our findings demonstrated that body length is a strong predictor of dry mass for most of the studied genera but some exceptions suggest that it may not fully capture biomass variation. The power models performed better in general, whereas the exponential and linear models were optimal for specific genera, indicating diverse influences on taxa allometry. This study reinforces the need to evaluate different approaches for estimating the dry mass of aquatic insects and underscores the caution required when using indirect methods for biomass determination.

Resistance profile of Escherichia coli strains in micro-basins with different soil use and occupation, in the Northwest of Rio Grande do Sul, Brazil

2024-11-24T12:39:24-03:00

Escherichia coli, a highly adaptive microorganism, has gained scientific interest due to its rapid mutation and resistance to antimicrobial treatments. The primary sources that contribute to its rapid spread and the emergence of infections remain hotly debated. Thus, the objective of this research was to provide a baseline, as the first study in the region that analyzes the microbiological quality of water in micro-basins with different characteristics of land use and occupation. Intending to identify whether there is resistance in the isolated strains of E. coli and what their possible origins are, the study provides a behavior modeling of the studied area. To this end, three sampling campaigns were carried out, from which these microorganisms were isolated and identified by polymerase chain reaction, and were subsequently subjected to susceptibility tests with nine antibacterials widely used in the treatment of infections caused by this bacterial species. Theresultsrevealed that the watershed receiving urban sanitary effluents presented the highest contamination levels, with persistent multidrug-resistant strains throughout the collection period. Among all strains, 80% were resistant to ampicillin, while 33.3% showed resistance to cefazolin. Levofloxacinwas the most effective antibiotic, with 100% susceptibility. Micro-basins with predominant agricultural and pasture activities demonstrated less resistance than urban-impacted areas. Thishighlights the urgent need for constant monitoring and further studies to uncover the main determinants of this urgent ecological and public health problem.

Low-temperature partitioning extraction optimized for antibiotics quantification in sewage sludge by liquid chromatography-tandem mass spectrometry

2024-12-06T11:32:42-03:00

Antibiotics and their degradation byproducts are a relevant group of contaminants of emerging concern. Conventional wastewater treatment plants fail to remove them. Thus, uncontrolled disposal of antibiotics in the environment increases the spread of antibiotic-resistant bacteria and their genes. The present work describes the development and validation of an analytical method for the simultaneous determination of three antibiotics—sulfamethoxazole (SMX), sulfadiazine (SDZ), and trimethoprim (TMP)—in sewage sludge. The method is based on low-temperature partitioning extraction (LTPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). LTPE is a low-cost extraction technique that does not require specific equipment, large amounts of solvents and samples, nor longer times to extract antibiotics from sludge. TheLTPE procedure was optimized for dried anaerobic sludge from upflow anaerobic sludge blanket reactors fed with sewage. Theinfluence of sample mass content, ultrasonic bath extraction time, and potential of hydrogen (pH) of the buffer solution on extraction efficiency was evaluated with experimental design methodology. Thebest conditions achieved to extract the target antibiotics were: 150 mg dried sludge, 20min of ultrasonic bath, and pH 7, in addition to 600 μL of McIlvaine buffer solution, and 600 μL organic solvent in one cycle of extraction. The recovery values were 52.7% (SMX), 53.6% (SDZ), and 70.1% (TMP), and the method exhibited good repeatability (≤14.7%). The method detection and quantification limits ranged from 3.6 to 11.3 ng g-¹ dw (dry weight) and 11.5 and 36.1 ng g^-1 dw, respectively. Sewage sludge samples collected from two municipal wastewater treatment plants in Minas Gerais state/Brazil revealed the presence of TMP (174.2 and 134.8 ng g^-1 dw) while sulfonamides were lower than the method detection limit. To the best of our knowledge, this is the first study based on LTPE followed by LC-MS/MS that was applied to simultaneously determine SMX, SDZ, and TMP antibiotics in sewage sludge.

Estimating the risk of wildfires in the municipality of Rio Verde, Goiás State, Central Brazil

2024-10-17T18:40:55-03:00

The damage caused by wildfires has major impacts each year, not only on the environment but also on the economy and public health. The present study aimed at mapping the fire risk in the different areas of the municipality of Rio Verde, in the Central Brazilian state of Goiás. A number of factors that influence the occurrence of wildfires were considered in this analysis, including the orientation of the relief, the slope, population density, proximity of homes, the road network, and land cover and use. The analytical hierarchy process was used to determine the appropriate weights for each of the variables. The fire risk index was divided into five classes: water, low, moderate, high, and very high risks. Class 4 (high risk) was the most frequently recorded within the study area, followed by classes 3 (moderate risk) and 2 (low risk). Subsequently, the heat spots recorded by remote sensing were related to fire risk indices, and the framing in the classes was verified. Overall, 16.36% of the heat spots were considered low risk (class 2), while 36.29% were classified as moderate risk (class 3), and 46.72% as high risk (class 4). These findings indicate that the fire risk index provides an adequate and effective parameter for the spatial assessment of the distribution of fire events (controlled burns or wildfires) in the municipality of Rio Verde.

Analysis of a photovoltaic-thermal with heat pump system for engine heating in thermal power plants

2024-10-27T08:04:29-03:00

This study performed a computational analysis and experimental validation of a hybrid photovoltaic-thermal (PVT) system combined with a heat pump for engine heating in thermal power plants. Using the Ansys Fluent software for computational fluid dynamics simulations, the research examined the thermal performance and efficiency of the PVT system under real operating conditions. The simulations confirmed that the PVT system could achieve high thermal efficiency, especially during periods of maximum solar radiation. The mesh model used in the simulations comprised 6,589,347 elements, refined to capture the details of fluid flow and heat transfer. The results indicated that the maximum outlet water temperature reached 315 K, while the experimental tests showed a maximum temperature of 328.15 K. The maximum thermal efficiency observed was 73% at noon. The study also demonstrated the feasibility of scaling up the system from a bench-scale prototype to industrial applications. By employing the Boussinesq approximation and maintaining the dimensionless Reynolds, Nusselt, Prandtl, Grashof, and Rayleigh numbers, the downscaled simulations were shown to be reliable and comparable to full-scale systems. The integration of the PVT system with a heat pump proved to be effective in reducing fossil fuel consumption, enabling simultaneous generation of electricity and heat, thereby improving energy efficiency and reducing operating costs in industrial settings. The PVT system faces climate constraints, high costs, and industrial integration challenges. The present study acknowledges the challenges in the widespread adoption of PVT systems and suggests future research to optimize these systems in diverse climatic and geographic contexts.

Microplastics in plant-based foods in the city of Itacoatiara (AM), Brazil

2024-12-16T20:48:55-03:00

Microplastics are practically ubiquitous contaminants in all environments on the planet. Therefore, the present work aimed to investigate microplastic contamination in lettuce, chives, and cilantro sold in Itacoatiara, Central Amazon, Brazil. Samples of each vegetable were acquired from different commercial establishments. The samples were washed with filtered distilled water to remove any particles present on the surface of the vegetables. Hydrogen peroxide was added to the water used to wash the vegetables to digest organic materials. The solution was stirred daily and kept in an oven at 60°C. The microplastic particles were separated using the density difference technique. In total, 247 microplastic particles were recorded. There was no significant difference in the number of microplastic particles per sample of the three types of vegetables. The size of the microplastic particles also did not differ significantly between the types of vegetables, with the smallest (0.067 mm) and largest (4.865 mm) particles being found in lettuce. The proportion of microplastic colors recorded on the vegetables varied significantly. Blue and red particles were predominant, with a greater abundance of blue particles (n=207; 83.8%). There was a significant difference in the proportion of microplastic particle formats, with fibers (n=235; 95.1%) being more representative than fragments (n=12; 4.9%). Thus, it can be confirmed that the vegetables sold in Itacoatiara, Central Amazon are contaminated, consequently unsafe for direct human consumption, and require washing with plenty of running water to eliminate microplastic particles before being consumed fresh.

Wood density of forest species in integrated crop-livestock-forest system in the Brazilian Amazon: challenges and opportunities for Bertholletia excelsa, Dipteryx odorata, and Khaya grandifoliola

2024-11-21T16:08:49-03:00

Wood density is the physical property directly related to the timber potential of a species and influences the environmental service of carbon storage and sequestration. Therefore, the objective of this study was to evaluate the wood density at different moisture levels (apparent, anhydrous, and basic) of the species Bertholletia excelsa, Dipteryx odorata, and Khaya grandifoliola in a young forest stand cultivated in an integrated crop-livestock-forest system. The Technological Reference Unit, established in 2010, highlighted the necessity for management interventions by 2021 to prevent excessive shading and eliminate phenotypically undesirable species. Material samples were harvested at five heights along the commercial stem to analyze wood density (anhydrous, apparent, and basic). Our results revealed that D. odoratahad the highest densities (0.99, 0.91, and 0.83 g/cm³), while B. excelsa and K. grandifoliola displayed lower densities (0.68, 0.61, 0.55 g/cm³and 0.61, 0.56, 0.51 g/cm³, respectively). Notably, D. odorata exhibited an increasing basic density from base to top, while K. grandifoliola demonstrated greater homogeneity along its stem. The presented results provide robust technical support to inform decision-making on the use of native and exotic species in integrated production systems, as well as emphasizing the potential of the crop-livestock-forest system as a sustainable production practice.

Analysis of water quality, bioindicators, contaminants and their cytogenetic impacts in a Cerrado reservoir

2024-11-18T09:27:56-03:00

The fragmentation of Brazilian rivers due to the construction of hydroelectric dams has altered aquatic ecosystems, resulting in the accumulation of residues in sediments. This study evaluated the cytotoxicity and genotoxicity of water and sediments from the Cana Brava reservoir, located in the Tocantins-Araguaia basin in the Cerrado biome, using the Allium cepa test. Sampling points were situated in the Cana Brava reservoir near two tributaries, the Bonito River and the Varjão Stream, areas susceptible to contaminant input due to proximity to urban areas. Physicochemical parameters, metals through atomic absorption spectrometry, toxicity, and analyses of bioindicators such as microalgae and macrophytes were assessed. Near the Varjão Stream, algal richness was higher, with the presence of Chara rusbyana, which indicates good water quality. Near the Bonito River, pollution-indicating microalgae such as Euglena sp., Nitzschia sp., and Oscillatoria sp. were identified, along with a prevalence of Salvinia auriculata, favored by nutrient availability. Cytogenetic tests revealed that sediments, especially from the site near the Varjão Stream, caused chromosomal abnormalities and cytogenotoxic effects, with an increase observed after 72 hours. Principal components analysis showed that phosphorus and potassium in the sediment from the site near the Bonito River correlated with cellular alterations at 48 hours, while sediments near the Varjão Stream resulted in a higher frequency of cytogenetic alterations at 72 hours. These results highlight local impacts on water quality and biological diversity, recommending continuous monitoring to mitigate the adverse effects of pollution in the Cana Brava reservoir.

A mobile strategy for water participatory monitoring

2024-10-31T15:26:27-03:00

The increase in industrialization and urbanization processes has directly affected the quality of water resources worldwide, generating impacts on public health and aggravating the availability of clean water. This study presents AQUA, a mobile application designed as a monitoring tool for urban rivers using colorimetric chemical tests. AQUA enables the analysis and storage of georeferenced data on pollutant levels across specific areas. Tests for ammonia (NH₃-N), orthophosphate (PO₄^3--P), iron, and nitrite (NO₂-N) were miniaturized and submitted to analytical validation, reaching satisfactory values according to the National Institute of Metrology, Quality, and Technology (INMETRO) guidelines, and presenting results comparable with the classic methodologies using UV-VIS spectrophotometer. The limit values of quantification were below the maximum thresholds established by Brazilian law for surface water quality. Nine urban rivers in Foz do Iguaçu (a city in the State of Paraná) were assessed, with high NH₃-N and NO₂-N levels, likely indicating untreated sewage discharges. The generated georeferenced pollution map provides a valuable tool for water quality control in local communities. Overall, this strategy enables participatory water quality monitoring in a cost-effective, flexible, and accessible manner, contributing to Sustainable Development Goal 6 by promoting water availability and sustainable management.

Diversification of crops and food security: the role of family farming in the COVID-19 pandemic

2024-09-13T20:27:19-03:00

Given the importance of family production, our aim was to characterize the productivity and importance of family production during the COVID-19 pandemic in the communities of Engano dos Rodrigues and Lagoa Seca, located in the municipality of Santana do Piauí. Data were collected by monitoring production and sales, from interviews and analysis of the strengths, weaknesses, opportunities, and threats (SWOT) matrix. The strengths of the activity lie in the diversity of food products and the continuous production of most items, in the organization into an association and the partnerships established, which were crucial at a time of crisis to guarantee the distribution and sale of agricultural products. The weak points are mainly related to the lack of technical assistance. Understanding the dynamics of agroecological family production in times of crisis highlights the importance of institutional support and continuing education for the resilience and sustainable development of rural communities. We also stress the importance of future research focusing on the impact of public policies on family farming in the semiarid region, as well as the effectiveness of different marketing and cooperation strategies among farmers.

Morpho-functional groups as an efficient tool for monitoring and management of the Billings reservoir (São Paulo, Brazil)

2024-10-14T11:46:00-03:00

This research applied the Morphology-Based Functional Groups (MBFGs) combined with classical approaches, such as community descriptor species and phytoplankton classes in the Billings reservoir. This local is the largest freshwater reservoir in the metropolitan region of São Paulo that has around 22 million inhabitants. Two sampling stations differing in predominant uses were studied: Rio Grande, classified as mesotrophic, and Central Body, as super and hypereutrophic. The phytoplankton and limnological variables were collected over six months (n=12). The trophic state index was calculated using phosphorus concentrations. Three canonical correspondence analyses were calculated aiming to examine the effect of environmental variables on the phytoplankton structure from each classification method (descriptor species, classes, and MBFGs), identifying the influence of environmental variables (independent variables) on the abundance patterns of the phytoplankton community (dependent variables). The highest concentrations of chlorophyll a and phytoplankton density were recorded at the site with the highest concentrations of total phosphorous (average of 99.86 μg/L in Central Body). This site was also associated with the highest electrical conductivity, total dissolved solids, turbidity, and concentrations of total nitrogen and chlorophyll a. The main factors associated with phytoplankton distribution were the trophic state and the operational system. It was concluded that the phytoplankton approach through MBFG efficiently responds to fluctuations in the ecological attributes of phytoplankton, and because they are based on morphological features, MBFG reduces the complexity of identifying and classifying organisms at a specific level.

Evaluating the attractiveness of different bait formulations for monitoring Liriomyza sativae (Diptera: Agromyzidae) adults

2024-09-12T12:19:39-03:00

The growing need for sustainable agricultural practices drives the search for effective alternatives in pest management. Insects like Liriomyza sativae cause significant damage to crops, requiring monitoring and control methods that minimize the use of chemical pesticides. In this context, the use of natural and synthetic attractants for pest capture offers a promising solution while contributing to the preservation of ecological balance. The objective of this work was to study the attractive effect of different formulations for L. sativae adults. The formulations were divided into two groups according to their composition. For group 1, they were based on vinegar and sugar, and for group 2, formulations were based on molasses, invert sugar, hydrolyzed protein, and eugenold. The attractiveness of the formulations was evaluated based on free choice. They were placed in tube-shaped plastic containers and randomly arranged in TNT cages. Evaluations were performed every 48 hours by counting the number of adults in the containers until there was a low capture rate. Data were subjected to analysis of variance testing and means were compared using the Scott-Knott test at 5% significance level. All formulations tested were attractive to adults of L. sativae, with groups 1 and 2 reaching their maximum averages of 55.60 and 68.00 adults, respectively. Both occurred during the second evaluation. Over time, all formulations showed a reduction in capture rate. The use of effective attractants promotes traps that monitor and even control the pest population in a more sustainable way, benefiting the agroecosystem with sustainable agricultural practices. Furthermore, the research expands knowledge about the chemical ecology of insect pests, providing a basis for the chemical communication of these organisms.

Charting the future of Brazil’s electricity: a multicriteria analysis of northeastern power strategies amidst climate challenge

2024-09-19T11:07:40-03:00

The article addresses the challenges faced by regions under water stress, such as conflicts over water use, environmental degradation, and water resource scarcity, intensified by climate change. In areas dependent on hydropower generation, these problems are exacerbated, highlighting the need to transition to more sustainable and resilient energy sources. The study emphasizes the importance of multifaceted criteria for an effective transition of the electricity matrix in semi-arid regions, taking into account economic, technical, environmental, and social aspects. Focusing on the São Francisco River basin in Northeastern Brazil, where the energy matrix is predominantly hydroelectric, the study uses the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to evaluate alternative scenarios, analyzing options for wind, solar, and thermoelectric energy. The methodology adopted included the close collaboration of experts in defining and weighting essential criteria, covering economic, technical, environmental, and social aspects. The results show that, within the same group, options that involve greater reductions in hydroelectric generation are more advantageous. Analyzing the ranking among all alternatives, the group that includes higher expansion of wind energy presents the most viable options, followed by the reference strategy (based on average annual generation) and the group with greater expansion of solar capacity. Increasing the share of gas-fired thermoelectric power is considered a less favorable solution according to the criteria used in the model.

The Brazilian State Water Resources Councils: diagnosis of civil society participation through criteria of access to information, parity, and decision-making procedures

2024-08-21T11:42:28-03:00

The aim of the article was to investigate whether the Brazilian State Water Resources Councils, including the Federal District, ensure civil society participation through access to information, parity, and decision-making procedures. In this context, verification criteria were selected, with maximum score of 1 point assigned based on their suitability for the Councils, which were classified in terms of participation adequacy. The states that were deemed suitable, in descending order, were: Paraíba (1st position), Mato Grosso do Sul, Minas Gerais, and São Paulo (2nd position), Amazonas, Pará, Paraná, Rio de Janeiro, Rio Grande do Sul, Rondônia, and Santa Catarina (3rd position), Bahia, Ceará, Federal District, Espírito Santo, and Mato Grosso (4th position), Rio Grande do Norte and Tocantins (5th position), and Alagoas (6th position). The states deemed unsuitable were: Acre and Pernambuco (7th position), Piauí and Roraima (8th position), Goiás and Sergipe (9th position), and Amapá and Maranhão (10th position). As for the criteria, the ones that scored the highest were: the presence of the website and Internal Regulations of the Councils, decision-making by the Council in plenary sessions, the presence of Meeting Minutes on the website, identification of the Technical Chambers of the Councils on these channels, adherence to the regular meeting schedule, identification of the members who make up the Councils, and parity among the three sectors that constitute them. It was concluded that the State Water Resources Councils need to ensure equal participation for civil society members in their discussions and deliberations as well as provide public access to the information generated.

Remote sensing applied to biophysical parameters and land cover to identify urban heat islands in Recife (PE), Brazil

2024-08-12T09:02:33-03:00

Urban growth results in several changes, mainly related to demographic, social, economic, and environmental aspects, leading to a new connotation in the use and occupation of land. This new scenario impacts the local energy balance, creating what is called an “urban heat island”. This study aims to investigate the occurrence of urban heat islands in Recife city, the capital of Pernambuco, Brazil, based on the processing of biophysical parameters, the classification of land use and occupation, and surface temperature. The orbital images of the study region were obtained and processed using the Google Earth Engine cloud processing platform from 2013 to 2021. The results showed an increase in areas with greater urban density and a reduction in areas with vegetation. It was realized that in regions with greater urban density, the surface temperature observed was up to 5.20°C higher than in the area with vegetation.

Potential of two floating aquatic macrophytes in improving water quality: A case study in two tropical streams

2024-08-21T15:57:06-03:00

The expansion of urbanization has led to significant adverse environmental effects, including the disposal of domestic sewage without treatment in water bodies. This impact contributes to the deterioration of water quality and poses serious risks to human health and the environment. In this context, effective and sustainable methods to mitigate the impacts should be explored, such as the use of plants capable of removing or degrading contaminants from water. The present study aimed to assess the phytoremediation potential of two free-floating aquatic macrophytes (Eichhornia crassipes and Pistia stratiotes) systems for enhancing the water quality collected from two polluted urban streams. The trials were performed in 25-L experimental units for seven days under ambient conditions. The water quality variables after the exposure period were compared to those at the beginning of the experiment to assess the potential improvements due to the presence of macrophytes. The systems with E. crassipes exhibited good performance in water samples from both streams, with reductions reaching 29.2% in dissolved solids, 36.8% in electrical conductivity, 44% in biochemical oxygen demand, 57% in nitrogen, and 45% in phosphorus. The systems with P. stratiotes also exhibited satisfactory outcomes, including 90 and 76.2% reductions in phosphorus levels of Santa Rita Stream and Galinha Stream, respectively, and 54% turbidity, and 38% biochemical oxygen demand in both streams. These findings highlight the potential of the two plant species for phytoremediation of polluted waters, considering their performance on short-term exposure. Therefore, this approach consists of a sustainable alternative by utilizing natural elements for environmental restoration, and the outcomes can contribute to future applications of phytoremediation techniques in developing countries.

Phytoremediation of microcystins using Myriophyllum aquaticum can prevent sublethal effects in a Neotropical freshwater catfish

2024-08-14T04:58:07-03:00

Microcystins are cyanotoxins that can be produced by cyanobacteria species such as Microcystis aeruginosa. Due to the presence of microcystins in water bodies and aquatic organisms, it needs to be monitored. Furthermore, additional studies are required in the implementation of alternative and sustainable water treatment methods. The aim of this study was to investigate the potential of Myriophyllum aquaticum to prevent the harmful effects induced by M. aeruginosa aqueous extract in Rhamdia. quelen usingbiomarkers and to assess whether the plant can be suitable for phytoremediation in aquatic ecosystems. In the first experiment, R. quelen was exposed to 1 and 10 μg.L^–1 of microcystins through an aqueous extract dissolved in the bioassay’s water. Second, tanks containing the same test concentrations of microcystins were treated by phytoremediation using M. aquaticum at 10 g.L^–1, for 7 days. After that, treated water was used in a new bioassay with fish exposure. The results showed that phytoremediation decreased the microcystin concentration in water, and different biomarker analyses demonstrated that M. aquaticum treatment prevented DNA damage, hematological alterations, and tissue damage in R. quelen. The phytoremediation with M. aquaticum can be a sustainable and cost-effective alternative to water treatment, highlighting its role in enhancing water quality and supporting biodiversity conservation. These results support the importance of adopting more restrictive legal limits for cyanotoxins in water to protect native aquatic species and promote sustainable water resource management.