Revista Brasileira de Ciências Ambientais

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.