Revista Brasileira de Ciência, Tecnologia e Inovação

Evaluation of methylene blue-removal by adsorbents recovered from industrial activity

2024-12-13T09:38:46-03:00

The study evaluated the application capacity of materials recovered from mining activities (nano hematite recovered from acid mine drainage and basaltic remineralizer (BR) (rock powder) discarded from quarries) as adsorbents in removing methylene blue dye. The adsorbent materials were characterized and had their zero-charge point determined, with pH_PCZ 6.5 for rock powder and 5.5 for hematite. The results showed that the basaltic remineralizer contains 51.1% silicon dioxide, 15.2% hematite, and 13.2% alumina. The analysis also indicated that the levels of heavy metals in the rock powder were within the limits established by CONAMA resolution 420/2008, suggesting safety in its application in the environment. The adsorption tests were performed in batches, using 0.5 g of adsorbent in 100 mL of 10 mg. L^-1 methylene blue solution. The experiments were performed in triplicate in the pH range of 2 to 6. The dye removal capacity was satisfactory, with hematite removing an average of 1.73 mg. g^-1 and basaltic rock powder 2.08 mg. g^-1. The greater efficiency of basaltic rock powder, even with a smaller amount of hematite (approximately 0.08 g), can be attributed to the concomitant presence of alumina, offering more active sites for dye adsorption. This study suggests new possibilities for removing textile dyes from effluents and adds commercial value to basaltic rock powder, a byproduct of the mining industry, and nanoparticles recovered from industrial activity.

Implementation of parcels of land micro-reservoirs as a strategy to reduce water volume in galleries and peak flows in the micro-drainage system of a new subdivision

2024-12-13T10:25:03-03:00

Urbanization has caused significant environmental impacts on natural cycles, particularly the hydrological cycle. Soil impermeabilization increases surface runoff, contributing to the higher frequency and intensity of urban flooding. This phenomenon underscores the growing vulnerability of cities to extreme events, which are further exacerbated by climate change. Precipitation patterns have been shifting due to climate alterations, necessitating adaptations to IDF curves, which are critical for planning climate adaptation strategies. In many cases, existing drainage systems are insufficient to handle the impacts of urbanization and intense rainfall events. In this context, the adoption of techniques that control flow distribution over time and mitigate peak flows may be crucial for flood control, especially in urbanized areas. Green infrastructure techniques, such as Low Impact Development (LID) practices, have proven effective in mitigating urban flooding. Among these measures, infiltration techniques such as green roofs and permeable pavements, as well as storage techniques such as retention basins, detention basins and rain barrels (RB), stand out. This study examines the impact of implementing RB in the microdrainage system of a new subdivision in the interior of Paraná. The simulations were conducted for return time of 1, 5, and 10 years, indicating potential failures in the drainage system. To prevent flooding, the strategic inclusion of RB was proposed to mitigate peak flows in the drainage galleries, preventing overflow and system overload, and reducing peak flow by up to 47%.

Environmental remediation of canga and iron mining waste pile using bee pasture of Baccharis dracunculifolia

2024-12-13T10:57:43-03:00

Mining is an economic activity known for its significant potential to generate socio-environmental impacts. In the case of iron ore mining in the Iron Quadrangle of Minas Gerais, the areas most frequently affected are typically ferruginous fields, due to vegetation suppression for pit opening and the deposition of waste rocks. Owing to their unique characteristics, these regions exhibit a high degree of endemism, with species adapted to the specific environmental conditions, making them suitable candidates for use in ecological restoration projects. Baccharis dracunculifolia is a native plant with significant potential for inclusion in such projects due to its ability to colonize degraded areas and its interactions with pollinators, such as the honeybee Apis mellifera. Consequently, environmental restoration efforts can be integrated with apicultural production, providing a sustainable alternative for the productive use of previously degraded land. The objective of this research is to identify and compare the physical and chemical properties of soils from iron mining waste piles and canga for potential use in environmental restoration with B. dracunculifolia as a bee pasture. Analyses included particle size distribution, bulk density, moisture content, pH, and chemical composition using X-ray fluorescence (XRF). Results indicated that both environments demonstrated similar properties across all tests, supporting the use of native plants such as B. dracunculifolia in ecological restoration projects. Furthermore, the establishment of bee pastures composed of this species in degraded areas can help diversify the income streams of local communities near mining operations, thereby reducing their dependency on mining activities.

Direct filtration system composed of coconut fiber as a filtering medium in water treatment

2024-12-13T11:27:37-03:00

The use of inorganic coagulants has sparked discussions regarding the potential consequences on human health. In contrast, polymeric coagulants derived from tannin compounds show promise in water treatment. An important issue is the use of alternative materials in the construction of filters used in water treatment, such as those made with coconut fiber. The objective of this study was to compare the performance of sand filters (F1) with coconut fiber filters (F2), as well as the use of the inorganic coagulant aluminum sulfate (C1) compared to the organic tannin (C2). The tests were performed in duplicate, and the parameters pH, electrical conductivity, apparent color, and turbidity were evaluated using R software. The results showed that the pH was not altered and that the electrical conductivity decreased after the application of both coagulants, with F2 achieving a reduction of up to 73.4% using tannin. For turbidity, F2 achieved removals of 95.44% and 81.35% for C2 and C1, respectively. When analyzing the apparent color, F2 removed 85.38% using C2 and 55.38% with C1, demonstrating the efficiency of the coconut fiber filtering material. However, the use of a large amount of water for cleaning this filter becomes a problem and an issue to be addressed.

Influence of positioning on the adaptability of vegetation in an experimental rain garden in a tropical urban environment

2024-12-13T11:56:05-03:00

Rain gardens have emerged as an alternative in stormwater management through infiltration and retention of precipitation on-site. The current literature shows a lack of studies evaluating the vegetation development processes in rain gardens and plant species exhibit better adaptation to the system, especially in tropical climate regions. In this context, this article aims to assess the influence of vegetation positioning on the adaptability of four native tropical climate species, namely, Mexican petunia (Ruellia simplex), song of India (Dracaena reflexa), spider plant (Chlorophytum comosum), and snake plant (Sansevieria trifasciata). For this purpose, plant growth was monitored biweekly for one year through measurements of height and diameter of the species cultivated in an experimental rain garden on a field scale. Analysis of Variance (ANOVA) was applied to verify the effect of plant location within the bioretention cell, evaluating whether certain microenvironments or specific positions favor or inhibit the species' development. Additionally, spatial distribution analysis of soil organic matter was conducted to assess potential heterogeneity in nutrient distribution. The evaluated species exhibited good adaptability, showing healthy morphological appearance and satisfactory growth. No statistically significant difference was identified in the interspecies growth rate in the monitored rain garden.

Soil bioengineering interventions for erosion control in hydroelectric power plant reservoirs

2024-12-16T16:53:07-03:00

The banks of water reservoirs are highly susceptible to erosion processes. Thus, interventions to mitigate and control erosion must be performed which are traditionally done using traditional engineering techniques (gabions, riprap, etc.), which have high execution and maintenance costs and high environmental impact. Soil Bioengineering is a viable alternative since it considers technical criteria in dimensioning works and values ecological and environmental factors. The objective of this work is to present a Soil Bioengineering intervention performed to stabilize and control erosion processes in a section of the Itá Hydroelectric Power Plant (Itá HPP) reservoir. The area is located in the Itá HPP reservoir and presents erosion processes with soil loss and transport causing reservoir silting. The section is 169 m long and was divided into subsection 1 (vegetated geotextile wall, vegetated palisades, planting of herbaceous, shrub and tree seedlings), and subsection 2 (vegetated coconut wall, vegetated palisades, planting of herbaceous, shrub and tree seedlings). The project was prepared in June 2020 and the work was performed in June-August 2021. The techniques were then monitored. The plants showed excellent survival and growth rates, the structures did not move or settle, and no erosion was detected. Soil Bioengineering techniques proved to be technically efficient in mitigating erosion processes on the banks of the Itá HPP reservoir. In addition to the technical benefits, the implemented solutions improved ecological and environmental functions, with reestablishment of native vegetation and an increase in floristic and faunal biodiversity.

Machine learning for predicting flow and pressure in an oscillating water column wave energy converter

2024-12-13T14:38:00-03:00

The use of wave energy presents itself as a renewable alternative, diversifying the energy matrix and reducing the consumption of fossil fuels. One of the prominent devices for ocean wave harvesting is the Oscillating Water Column (OWC), which consists of a hydropneumatic chamber where the oscillation of the water surface compresses the confined air, driving a turbine. This work combines numerical simulation and machine learning algorithms, aiming to develop predictive models for mass flow rate and pressure through the OWC chamber. The database for the models was created using Design of Experiments (DOE) techniques, where different combinations of wave height and wavelength were simulated via Computational Fluid Dynamics (CFD) using the Finite Volume Method (FVM). Subsequently, the wave elevation height data is fed into a fully connected deep neural network, which uses the simulated data for learning and returns predictions based on the provided information. The model's performance is evaluated in terms of a cost function (Mean Squared Error). The employed model allows for the identification of flow rate and pressure peaks for the wave period provided at the input, and the results show differences of up to 5% in RMS (Root Mean Square) between the predictions and the CFD data. The main contribution of this work lies in the use of machine learning in predicting traditional operating conditions of an OWC device, introducing a concept that can be applied in the early stages of the design of such devices.

Analysis of Urban Stream Water with Effluent Discharge in the West Region of Mato Grosso

2024-12-13T15:25:00-03:00

Between January 9 and 11, 2024, an expedition was conducted across 12 municipalities in the western region of Mato Grosso to assess the water quality of urban streams receiving domestic effluents. For this purpose, the Water Quality Index (WQI) and a Rapid Assessment Protocol (RAP) were used to analyze water pollution and anthropogenic impacts surrounding these watercourses. One water body was selected per municipality. Water samples were collected downstream of the effluent discharge point for both physicochemical and microbiological analyses. Results indicated that some surface water sources were classified as altered or impacted due to the presence of sewage and vegetation cover removal. Variables such as fecal coliforms and phosphorus exceeded legal limits. Additionally, nine municipalities were classified with a poor WQI level. Municipalities with less efficient effluent management exhibited worse water quality. The study concluded that the region faces serious challenges in effluent management and water conservation. The need for investment in sanitation infrastructure and environmental management is highlighted to mitigate negative impacts, protect public health, and preserve local biodiversity.

Evaluation of the temporal evolution of the water quality of the Mãe d'Água Dam

2024-11-18T17:05:09-03:00

The Mãe d'Água Dam, located on the UFRGS campus, was built for landscape and research purposes, but over time suffered from pollution by solid waste, domestic effluents, and sediments, as well as eutrophication. This study aimed to evaluate the temporal evolution of dam water quality, comparing data with the parameters of CONAMA Resolutions nº 357/2005 and CONSEMA nº 355/2017, by calculating the Water Quality Index (WQI). Between December 2023 and April 2024, monitoring was performed at four distinct points of the dam, measuring parameters such as pH, turbidity, and dissolved oxygen, using a multiparameter probe. The results showed that points P1 and P4 had WQI indicating regular water quality, while points P2 and P3 exhibited poor quality. The P3 point presented high turbidity, suggesting contamination by sediment and organic matter, while the P2 point had low concentration of dissolved oxygen, possibly due to the presence of untreated effluents. These results highlight the degradation of water quality in specific areas of the dam, raising concerns about environmental impacts on the ecosystem and adjacent communities. The research reinforces the need for continuous monitoring and mitigation actions to preserve the environmental health of the dam and its surroundings.

Thermal modelling of Green Roofs

2024-12-13T16:42:04-03:00

Urban changes highlight the need for expand vegetated spaces in built environments. In this sense, green roofs represent a valuable opportunity due to their potential to provide ecosystem services. Among the components of green roofs, substrates are essential and can be optimized to enhance their thermal properties, thus influencing heat transfer into buildings. Using additives in substrates for thermal optimization is a promising approach, especially when these additives include environmental by-products that make the substrates lighter and more cost-effective. The thermal performance of green roofs is also influenced by meteorological conditions that regulate substrate temperatures. This study conducted thermal modeling of the internal temperature of five green roof substrates by using generalized additive models and linear models based. Data collected during the summer months of 2021 and 2022 from five identical green roofs, except for their substrate composition - local soil (SOIL), commercial substrate (SCOM), and three mixtures incorporating carbonized rice husk, construction waste, vermiculite, and vermicompost into the local soil (SC2, SC4 and SC5) - were assessed. The correlation between monitored temperatures and meteorological variables was also assessed. The results showed correlations ranging from moderate to strong between the internal temperature of the substrates and climatic variables, especially temperature and humidity. It was proposed a predictive model for the internal temperatures of green roofs, achieving a Nash-Sutcliffe coefficient of up to 0.86, effectively evaluating the thermal benefits of green roofs under different meteorological conditions.

Assessment of water volumes granted and water availability in the Azul River basin, Paraná, Brazil

2024-12-16T11:41:00-03:00

Water plays a crucial role in various activities concerning a watershed. However, the unregulated utilization of water resources and the absence of effective management can jeopardize the diverse uses of water, turning a particular region into a critical area. Therefore, the aim of this study was to conduct a comprehensive analysis of water demands in relation to water availability in the Azul River Watershed, Paraná state, Brazil. To achieve this objective, data on licenses for water resources use issued by the state regulatory agency have been utilized, and the study area was defined using geographic coordinates. By segmenting the hydrographic unit, it is possible to identify different types of water uses (consumptive and non-consumptive), permitted water outflows, specific purposes, and water users. Furthermore, an examination of the conflicts between demand and water availability was also conducted. The findings revealed that the agricultural sector accounted for the highest water withdrawals, with the greatest number of active permits. Additionally, regarding consumptive uses, aquaculture emerged as the largest consumer of water, accounting for 62% of the total water consumption. The water demand of users in the Rio Azul basin cannot be achieved considering the current licensing criteria. This indicates that water resource management requires special attention to the relationship between demand and water availability.

SUDS: Environmental remediation applied to urban drainage

2024-12-13T14:14:53-03:00

The few strategies used to remediate polluted urban waters have focused on reducing gross pollutant loads with a view to improving the aesthetics of streams and receiving rivers. However, many researchers have sought to evaluate the efficiency of percolating beds, operating by gravity, in removing contaminants from urban rainwater, valuing the short time for treatment and low maintenance. The various percolating beds tested proved to be effective in removing pollutants found in collected urban runoff, particularly metals. Notably, the composition of the prototypes included vermiculite, a clay mineral that demonstrated superior results compared to those made solely from sand, justifying its adoption. In this way, new devices based in this principle, could contribute to the implementation of water requalification actions in small, highly urbanized river watersheds dominated by diffuse contamination sources, with the implementation of treatment systems at the end of the drainage networks.

Environmental Research focused on Environmental Strategies

2024-12-16T14:34:59-03:00

This special issue of the Revista Brasileira de Ciência, Tecnologia e Inovação (RBCTI) brings thirteen unpublished papers, which deal with different approaches related to environmental studies, carried out in many states of Brazil. These are studies developed by professors and post-graduate students of different institutions.