Brazilian Journal of Environmental Sciences (RBCIAMB)

Using mobile air quality station data to identify critical areas in the city of Rio de Janeiro regarding pollutant concentrations

2023-08-10T21:09:41-03:00

Recent studies have shown that tropospheric ozone, fine particulate matter and nitrogen dioxide are the urban air pollutants of major concern regarding human health effects. Monitoring air quality is a challenge in several cities, such as Rio de Janeiro, where the number of fixed-site air quality monitoring stations and their spatial distribution are insufficient to assess the extent of atmospheric pollutants. However, despite this lack of resources, the data obtained by mobile stations are a valuable means of determining which areas are experiencing critical air quality conditions, and provide key information for an air quality management program. The main purpose of this study was to conduct a critical analysis of data obtained by the Municipal Department of Environment and Climate (SMAC) mobile station in the period 2010–2018. Concentrations determined for particulate matter with a diameter ≤2.5 μm (PM_2.5), O₃, NO₂, SO₂ and CO showed that PM_2.5 and O₃are the pollutants of major concern, and that the north of the city has higher air quality indices for these compounds. In addition, the south-west district had relatively high ozone levels, probably owing to low concentrations of NO₂ in a volatile organic compound (VOC)-limited ozone formation regime. These factors should be considered by the municipal government in future discussions of control strategies for managing the city’s air quality. This study also shows the value of mobile stations in making a preliminary survey of pollutant concentrations, mainly in countries with limited financial investment in air quality management.

Bibliometric review of electro-electronic waste (WEEE) in the Web of Science database: groups’ production and main themes

2023-08-19T20:29:29-03:00

The waste of electrical and electronic equipment (WEEE) has been one of the largest and growing wastes generated in the world, turning into a great challenge for humanity. The objective of the article was to map the scientific production on WEEE in the last decade (2012–2022), adopting a bibliometric analysis as a research method based on the survey of documents obtained from the Web of Science database. A total of 278 research and review articles were selected for analysis, with the use of Vosviewer and RStudio software. As a result, there was a significant increase in the number of publications in the last decade, with 86% of articles published between 2015 and 2022. In addition, it was possible to obtain the ranking of the most important authors, and the journals most used for publication of articles; it was found that the Asian, European and American continents had the greatest contribution. In the analysis of document coupling, combined with that of keywords, the main areas connected to WEEE currently researched were found: electronic waste recycling; environmental impacts; sustainability; circular economy; efficient e-waste management and e-waste recycling technologies; in addition, the keywords “e-waste” and “polybrominated diphenyl ethers” were the most frequent words used by the authors to represent the theme. It can be concluded that the theme has stood out over the last few years, with several publications providing managerial and political implications for researchers and professionals.

Initial establishment of Erythrina velutina Willd seedlings under water deficit: physiological and biochemical aspects

2023-08-28T14:53:02-03:00

For plant species to establish and survive in semiarid regions, such as the Caatinga plant domain, they need to present biochemical versatility. Thus, the objective of this study was to evaluate through physiological and biochemical indicators the sensitivity of seeds and seedlings of Erythrina velutina Willd to water deficit, as this species is used in the recovery of degraded areas in the Brazilian semiarid region. The seeds were submitted to five osmotic potentials (-0.1; -0.2; -0.3; -0.4; and -0.5 MPa), evaluating the percentage of germination (normal seedlings), germination speed index, length of aerial parts and root system, total dry mass, the concentration of photosynthetic pigments (chlorophylls a, b, and carotenoids) in aerial parts and root system, soluble carbohydrates and proteins, proline, and the enzymes ascorbate peroxidase, catalase, superoxide dismutase, peroxidase, and polyphenoloxidase. The water deficit reduced the germination speed index and percentage, aerial parts and root length, aerial parts and root dry mass, and photosynthetic pigment content in seedlings; however, there was an increase in the levels of total carbohydrate, proline, and protein, and a reduction in superoxide dismutase. The water potential from -0,4 MPa was a limiting factor for the seedling and/or seedling formation process. The direct sowing of E. velutinawould only be indicated up to the potential of -0,3 MPa for the regeneration of degraded areas in semiarid regions. The species in the seedling formation stage present less biochemical plasticity to overcome limiting conditions of water availability.

Methodology for IDF equation based on reduced pluviograph records

2023-08-26T14:16:18-03:00

In the climate change scenario, extreme rainfall events are increasing in significance and frequency. It is essential to estimate the maximum precipitation intensity for designing hydraulic-hydrological structures, such as macrodrainage. Thus, this study makes a comparison between disaggregation coefficients and forms of the intense rainfall equation to determine an Intensity, Duration and Frequency (IDF) equation for Barcarena-PA. The rainfall historical series available in the Hidroweb database extends between 1981 and 2018. The Gumbel distribution presents the best fit in the return periods: 2, 5, 10, 50, 100, 200 and 1000 years, by the following tests: Filliben, Variance and Kolmogorov-Smirnov. The disaggregation of 1-day precipitation into shorter durations was done in two ways: using disaggregation coefficients recommended by the literature, as well as local disaggregation coefficients. For the construction of the IDF equation, two frequently used representations were considered: the first based on the determination of the coefficients: K, a, b and c; and the second, described in the Pluviometric Atlas of Brazil (APB), determines the coefficients: A, B, C, D and δ. The results indicated that the use of local disaggregation coefficients, in this case DC_Barcarena, with adjustment coefficient R²=0.9945, together with the use of the equation described in the APB, provides the best fit, R²=0.9998, to historical data. When compared with other IDF equations from Barcarena-PA, the previous finding is clear in terms of underestimating the intensity values. Thus, the methodology presented here can be extended to locations with reduced sub-daily rainfall records associated with large annual maximum daily rainfall records.

Influence of climatic phenomena and deforestation on hydroenvironmental fragility, Gurupi River watershed, Northern Brazil

2023-07-23T18:28:11-03:00

In recent decades, climatic and anthropogenic pressures have caused serious environmental problems. The joint analysis of geo-environmental variables, through geoprocessing techniques, can support the estimation of the contribution of each environmental component to hydro-environmental fragility (HF). The aim of this work was to analyze the contribution of climatic phenomena and deforestation in the HF of the Gurupi River Watershed (GRW). Precipitation data were extracted from the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS); land use and cover were obtained from the MapBiomas Project; drainage network was acquired from the National Water and Sanitation Agency (ANA); slope data were gathered from the National Institute for Space Research (INPE); soil data were obtained from the Brazilian Agricultural Research Corporation (EMBRAPA); geomorphological units were extracted from the Brazilian Institute of Geography and Statistics (IBGE); and rock data were based on the Geological Survey of Brazil (CPRM). For the mapping of HF, the Analytic Hierarchy Process (AHP) was adopted to weigh the importance of each variable in four extreme precipitation year scenarios (1989, 2012, 2015, and 2019). It was observed that spatial precipitation is considerably different in extreme years. Results showed that deforestation has increased over the years; and that static geo-environmental variables (drainage, slope, soils, geomorphological units, and rocks) have larger feature domains that favor the increase of HF in the GRW. The HF of the GRW showed significant differences in the analyzed scenarios. Policies and environmental conservation programs are needed in the GRW.

Biochar in copper reduction in black beans and soil decontamination

2023-09-12T11:20:27-03:00

When present in high concentrations in the soil, copper causes toxicity in plants, requiring the development of studies for the reduction or immobilization of this element. In this sense, biochar could be an alternative to immobilizing copper in the soil, aiming for lower levels of this element in the biomass and grains of black beans (Phaseolus vulgaris) used for human consumption. However, there are variations in biochar reactivity due to its source material and pyrolysis time. Therefore, the objective of the present study was to determine the effect of eucalyptus biochar on the availability of copper in the soil and on its contents in beans grown in contaminated soil. The experimental design was completely randomized in a 5 × 2 factorial arrangement, with five doses of biochar (0.0, 0.5, 1.0, 1.5, and 2.0% mm^-1 of dry soil), soil without and with the addition of copper (1,000 mg kg^-1 of dry soil), and with eight repetitions. Thecopper content available in the soil, root, aerial part, and bean grain; the chlorophyll index; and the bioconcentration and translocation factors of copper in the plant were evaluated. Biochar derived from eucalyptus residues decreases copper availability in contaminated soil. The copper levels in the roots, aerial part, and grains of P. vulgaris are reduced with the application of biochar to the soil, remaining in the grains, from a dose of 1.66% mm^-1, below the maximum limit tolerable by Brazilian legislation.