EECA - Artigos publicados em periódicos

URI Permanente para esta coleçãohttp://200.137.215.59//handle/ri/1287

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Incêndios florestais: diagnóstico e evoluções implementadas para combate, Espírito Santo, Brasil
(2025-10) Neves, Felipe Patrício das; Barboza, Raphael Nardoto; Simões, Eduardo Rodrigo; Ferreira, Nilson Clementino
Forest fires, increasingly frequent in various regions of the planet, are capable of causing countless damages to society and the environment. In this context, diagnoses and strategic response actions are very important, due to the scarcity of financial, human and logistical resources. Thus, this study aimed to analyze the dynamics of Forest fires in the are a of activity of the 2nd Military Firefighter Battalion, in the State of Espírito Santo, between 2015 and 2019, in order to support appropriate coping strategies. We also sought to describe the advances implemented in response actions in vehicles and equipment, addressing important issues such as weight, maneuverability, range, water consumption and necessary operators. For this, data from the Integrated Operational and Social Defense Center and the National Institute for Space Research were used, the QGIS geoprocessing software was used to prepare maps, and, finally, technical specifications. With 2,364 occurrences, the most attended municipalities were Linhares 1,028 (43.5%), Nova Venécia 529 (22.4%) and Barra de São Francisco 293 (12.4%), with the annual critical period being between August and October (39.7%). Froms at ellite records, there were 758 hot spots, highlighting the municipalities of Linhares 364 (48.28%), Ecoporanga 58 (7.69%) and Nova Venécia 51 (6.76%). Subsequently, the progress made in combat vehicles was discussed, starting with the Auto Bomba Tanque Salvamento, followed by the trucks equipped with the forestry kit and the Auto Bomba Tanque Florestal, emphasizing mainly the advantages and disadvantages in operations. Therefore, relevant information was obtained in this study with the aim of supporting optimized management strategies for responding to such disasters, which are increasingly frequent in the State.
Acúmulo de lodo em lagoa anaeróbia primária tratando esgoto sanitário
(2025) Teixeira Junior, Wellington; Freitas, Elaine Cristina Brás de; Cuba Teran, Francisco Javier; Cuba, Renata Medici Frayne
This study presents the results obtained from an experimental investigation carried out at the anaerobic pond of the wastewater treatment plant in the city of Goiatuba, Goiás, Brazil, from 2003 to 2014. The main objective was to assess the evolution of thesludge layer in this pond and to verify the applicability of the accumulation rates proposed by Von Sperling (2005), Mara (2003), Gonçalves (1999), and the model developed by Saqqar and Pescod (1995). The bathymetric survey conducted at the pond bottom indicated a sludge accumulation of 801.813 m³, a value lower than the 1,212 m³ estimated by applying the model of Saqqar and Pescod (1995). When applying the rate proposed by Mara (2003), the estimated sludge volume was 1,622 m³, whereas the application of the rates proposed by Von Sperling (2005) and Gonçalves (1999) resulted in a volume of 1,216 m³.
Variabilidade temporal e espacial da erosividade das chuvas no Estado de Goiás segundo três modelos
(2025) Pena, Diogo Silva; Ferreira, Nilson Clementino; Moreira, Alisson Neves Harmyans
The Universal Soil Loss Equation (USLE) is widely used to estimate soil erosion, with rainfall erosivity (R) being a key factor. This study evaluated three different methods for estimating the EI30 index in the state of Goiás, proposed by Morais et al. (1991), Lombardi Neto and Moldenhauer (1992), and Silva et al. (1997), using precipitation data from the Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS) from 1985 to 2017. The annual variability of erosivity was analyzed through linear regressions and statistical tests. Results showed that the average EI30 values for the models of Lombardi Neto and Moldenhauer (1992), Silva et al. (1997), and Morais et al. (1991) were 6,658.82, 6,947.32, and 13,017.70 MJ mm ha⁻¹ h⁻¹ year⁻¹, respectively, with an annual variation of 9.3%. The model by Silva et al. (1997) performed best (R² = 0.9997) and was more compatible with the observed mean values. It was concluded that erosivity varied significantly over time, though with low magnitude, and that the average of the three models adequately represents the spatial and temporal variability of rainfall erosivity in Goiás.
Removal of ibuprofen in aqueous medium by adsorption in biochar produced from coffee grounds and activated with hydrogen peroxide
(2025) Andrade, Caroline Pereira de; Costa, Luiza Vilas Boas Brandão; Cuba, Renata Medici Frayne; Cuba Teran, Francisco Javier
The presence of drug compounds in the environment, especially in water, is harmful to humans and to the balance of the ecosystem. The entry of drug residues into the environment can occur by the release of treated or raw domestic sewage in water bodies, since most sewage treatment plants are not efficient in the removal of these compounds. Therefore, research on methods of drug and other contaminants removal is extremely important. Considering that ibuprofen is one of the most consumed drugs in the world, the aim of this study is to verify the removal of ibuprofen from aqueous medium using adsorption in H2O2-activated biochar (ABC) produced from coffee grounds. For the characterization of the biochar produced, zero charge point determination and identification and quantification of functional surface groups were performed. The adsorption process was evaluated by pH influence tests, influence of ABC mass and adsorption kinetics. The efficiency of biochar produced was 70.2% (qe = 46.57 mg/g) for an initial concentration of 120 mg/L and for a contact time of 2 h. Thus, it can be concluded that the biochar produced presented satisfactory results, contributing to the removal of ibuprofen in aqueous medium
Removal of polyethylene microplastics by chemical coagulation: contributions to environmental pollution control
(2025) Rodrigues, Guilherme Aires; Vieira, Nelson Alves; Cuba Teran, Francisco Javier; Cuba, Renata Medici Frayne
This study evaluated the coagulation process using Aluminum Sulfate (Al₂(SO₄)₃) for the removal of pristine and aged low-density polyethylene (LDPE) microplastics (MPs). The methodological procedure consisted of an experimental assay applying coagulation in specialized equipment (Jar Test) for MP removal, with turbidity analysis as a control parameter for coagulation/flocculation efficiency. Subsequently, the treated samples underwent laser granulometry to assess the Mean Diameter (Mz) parameter, evaluating the coagulant’s effect on aggregate formation. The key findings demonstrated optimal removal efficiencies for pristine and aged MPs (30, 90, and 120 days), with maximum removal rates of 96.47%, 97.85%, 99.07%, and 77.28%, respectively. This technique proved highly effective in MP removal, particularly for MPs degraded up to 90 days.
Remoção do microplástico por meio de flotação por ar dissolvido
(2025) Aparecida, Geovana Célia; Cuba Teran, Francisco Javier; Cuba, Renata Medici Frayne
Environmental contamination by microplastics (MPs) has emerged as a major challenge, affecting aquatic ecosystems and posing potential risks to human health. This study evaluated the efficiency of dissolved air flotation (DAF), combined with coagulation and flocculation, for the removal of four types of MPs: high-density polyethylene (HDPE), polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS). Bench-scale experiments were performed using a 2 L floteste unit with a 20% recycle ratio. Three experimental conditions were assessed: (i) control (only MPs in suspension), (ii) coagulation with aluminum sulfate (Al₂(SO₄)₃), and (iii) coagulation combined with anionic polyacrylamide (PAM). Treatment efficiency was quantified by turbidity reduction. Results revealed that removal performance depended strongly on polymer type and treatment condition. PET achieved the highest removal (91.3%) under simple coagulation, attributed to its surface polarity. PE performed best (82.6%) when PAM was added, as denser flocs favored particle capture. HDPE consistently showed high removal (>80%) in all conditions, benefiting from its low density that enhanced flotation. In contrast, PS showed the lowest removal (max. 66.2%), explained by its high hydrophobicity that hindered interaction with coagulants. Overall, DAF integrated with coagulation–flocculation proved effective for MP removal; however, its efficiency is strongly dependent on the physicochemical properties of each polymer.
Análise da recorrência dos impactos causados por fogo no Distrito Federal com uso SIG
(2025) Pinto, João Henrique Corrêa; Rocha, Giliard Carlos da; Silva, João Rafael Freitas da; Ferreira, Nilson Clementino
The Cerrado, the second largest biome in Brazil, is present in the Federal District (DF), where protected areas face strong anthropogenic pressure, especially due to recurrent wildfires. This study aimed to analyze the historical sequence of burn scars in the DF from 2007 to 2022. It also evaluated the burned area history, affected phytophysiognomies, as well as the spatial distribution and recurrence of wildfires. Data were sourced from the Geoportal DF, Mapbiomas Fire, and Land Use and Cover projects, obtained through Landsat sensors (30 m resolution). Data processing was carried out using Google Earth Engine and QGIS. Results showed that few areas experienced more than six fire events during the period, with highlights including the Boca da Mata Ecological Park and FLONA IV. It was observed that fire recurrence is significantly lower in the year following a burn, stabilizing after two years. The study concludes that annual intersections of burned areas presented lower means and medians compared to longer time intervals, highlighting patterns that can support prevention and response strategies by relevant agencies.
Tratamento de efluente de abatedouro de bovinos por coagulação com sulfato de alumínio em reator de bateladas
(2025) Silva, Tiago Osório da; Rocha, André William Soares; Cuba Teran, Francisco Javier; Cuba, Renata Medici Frayne
Many water treatment plants operate above their design capacity, requiring increased flow rates due to growing demand. Most of these facilities traditionally use aluminum sulfate as the primary coagulant, with limited application of polymers as flocculation aids. Often, the selection of these reagents does not consider the specific characteristics of the raw water. To meet water quality standards and address inevitable overloading, it is essential to identify the most suitable coagulant and/or flocculation aid for each case. Laboratory-scale evaluations are thus crucial to determine the optimal combinations that ensure treated water of adequate quality and quantity at the lowest possible cost. This study reports on an investigation carried out at a water treatment plant designed for a nominal flow rate of 120 L/s but operating at 158 L/s. Under these conditions, the decanted water exhibited high turbidity and color levels, compromising filtration performance. Coagulation tests were conducted using different products to assess their effectiveness in impurity removal. As a result, significant improvements in both decanted and filtered water quality were achieved, along with an increase in treatment capacity. Currently, the plant can treat up to 280 L/s while maintaining water quality in compliance with Ordinance CONAMA 430, (2011), and with notable reductions in chemical consumption. These findings underscore the importance of reassessing coagulation strategies, particularly in overloaded systems, to enhance operational efficiency and ensure compliance with drinking water quality standards.
Processo oxidativo avançado UV/H₂O₂ aplicado ao tratamento de efluente industrial sintético contendo diferentes corantes orgânicos
(2025) Martins, Frederico Venancio; Cuba Teran, Francisco Javier; Cuba, Renata Medici Frayne
Objective: The objective of this study is to investigate dye removal through the application of advanced oxidation using hydrogen peroxide and ultraviolet light. Theoretical Framework: Dyes are molecules that, even at low concentrations, can alter the color of a product. In most cases, they are resistant to degradation by biological processes and generally exhibit low removal efficiencies. For these cases, in which biological treatment is ineffective, Advanced Oxidation Processes (AOPs) emerge as an effective alternative for the treatment of effluents containing toxic and biologically recalcitrant pollutants. AOPs involve the generation of highly reactive and non-selective oxidizing species, particularly hydroxyl radicals (•OH), to degrade persistent pollutants in industrial effluents, surface water, and groundwater. The UV/H₂O₂ process is an AOP that offers several advantages over other processes, mainly because it does not generate solid residues post-reaction; it is entirely consumed and does not produce byproducts. Method: The methodology adopted in this research involved the use of a bench-scale photochemical reactor in which the dyes Cromax Yellow AT, Cromax Blue AT, and Brown were applied. Dye removal was achieved through advanced oxidation using hydrogen peroxide (H₂O₂) and ultraviolet light (UV). Data collection was conducted through spectrophotometry.Results and Discussion: The results obtained revealed [synthesize the main results of the research]. In the discussion section, these results are contextualized in light of the theoretical framework, highlighting the implications and relationships identified. Possible discrepancies and limitations of the study are also considered in this section. Results and Discussion: Color removal efficiencies of 85% and 95% were obtained at 30 and 60 minutes, respectively, for Cromax Yellow AT, Cromax Blue AT, and Brown. The dye removal kinetics were determined to follow a pseudo-first-order model, with a pseudo-first-order rate constant of 8.75 × 10⁻² min⁻¹ and a half-life of 7.92 minutes. Research Implications: The results demonstrate that advanced oxidation using H₂O₂ and UV is effective for removing the studied dyes, which is relevant for environmental protection and pollutant mitigation. Originality/Value: This study contributes to the literature by evaluating the removal efficiency through the application of H₂O₂ and UV, both of which are readily available and easy to apply. The relevance and value of this research are underscored by its practical implications for effluent treatment.
Análise da severidade do fogo no Cerrado - NDVI Ponderado
(2025) Dornelas, Mario Henrique Monteiro; Ferreira, Nilson Clementino
The Cerrado stands out for its unique biodiversity, but it suffers intense anthropogenic pressure, driven mainly by agricultural expansion. Among the main disturbances, fire plays a central role. Although natural to the biome, the increase in human-induced burning has intensified its severity, negatively impacting both fauna and flora. Given the biome’s complexity and heterogeneity, analyzing fire severity requires specific approaches. In this context, remote sensing and the use of spectral indices have proven to be effective tools for mapping burn scars and assessing fire impacts. This study applied such indices and proposed a modification to ΔNDVI (called Weighted NDVI) to evaluate the severity of a wildfire that occurred in 2023 in the Águas do Paraíso State Park (PEAP), Goiás. Although the indices showed statistical similarity, the practical applicability of the Weighted NDVI in contexts of public communication and environmental management may serve as an accessible tool for disseminating fire severity information in the Cerrado.
Avaliação da presença de fase livre em um posto revendedor de combustíveis
(2025) Souza, Valéria Menezes de; Hoffmann, Nora Katia Saavedra Del Aguila
Fuel retail stations are responsible for extensive areas with environmental liabilities worldwide. The introduction of fuels into the environmental matrices of soil and groundwater introduces the chemical substances benzene, toluene, ethylbenzoate, xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAH) into these environmental compartments, hindering the exploitation of subsurface water by communities and causing environmental and social damage. This research aimed to evaluate the environmental quality of the soil and groundwater at a fuel retail station, given the risk to human health and the deterioration of the environmental matrices involved. To this end, the methodological approach adopted consisted of bibliographic research and field visits, where it was possible, through soil and groundwater sampling, to determine the environmental conditions of the area. The field visit revealed the presence of free-phase plumes in five monitoring wells. Laboratory analyses of soil from the boreholes showed contamination by BTEX and PAH at concentrations ranging from 0 to 0.2227 mg/kg and 0 to 0.1498 mg/kg, respectively. Furthermore, dissolved-phase contamination by BTEX and PAH compounds was identified in seven monitoring wells, where the concentrations of these chemicals ranged from 0 to 683.87 μg/L and from 0 to 181.85 μg/L. It is necessary to implement remediation measures as soon as possible to contain the advance of free-phase and dissolved-phase plumes. In addition, BTEX and PAH levels should also be monitored in any water intake wells in the vicinity of the site, thus preventing the possibility of ingesting water contaminated by hydrocarbons.
O risco ambiental relacionado à presença de postos revendedores de combustíveis próximos a corpos hídricos no estado de Goiás
(2025) Souza, Valéria Menezes de; Hoffmann, Nora Katia Saavedra Del Aguila
Fuel stations are potentially polluting activities, encompassing extensive areas with environmental liabilities resulting from this activity. When leaks occur in the equipment at fuel stations, compounds such as benzene, toluene, ethylbenzene, and xylenes (BTEX) and polycyclic aromatic hydrocarbons are released into the environment. These chemicals are known for their carcinogenic, mutagenic, and teratogenic effects on humans and their high toxicity to living beings exposed to them. Therefore, the objective of this study was to highlight the potential risks of these establishments located near surface watercourses and the harm that residents living near these establishments may be exposed to when tapping groundwater contaminated by hydrocarbons. To this end, the geographic location of 150 fuel stations distributed across 37 municipalities in Goiás was evaluated. Data from an environmental consultancy specialized in the respective activities and the database of the Municipal Environmental Agency (AMMA) of Goiânia, one of the municipalities evaluated, characterized the surroundings of the fuel stations. The results showed that, of a universe of 150 fuel stations, 8 (5.3% of the total) had water bodies within 200 m of them, and 2 (1.3%) of these stations presented environmental contamination. Furthermore, it was noted that subsurface water wells were located within 200 m of 45 (30%) establishments, and of these, 1 (0.7%) and 7 (4.7%) of these establishments presented contamination by BTEX and/or PAH in soil and groundwater, respectively. The deterioration of environmental matrices, resulting from the introduction of chemical substances from petroleum, causes significant damage both to the population that uses groundwater and to organisms that are exposed to pollutants.
Contribuição per capita de esgoto fecal em residências de comunidades quilombolas rurais
(2024) Silva, Adivânia Cardoso da; Scalize, Vinicius Baroni; Ruggeri Junior, Humberto Carlos; Scalize, Paulo Sergio
The accuracy and efficiency of developing sanitation infrastructure projects are directly linked to the use of water consumption data that reflect the reality of local communities. This study aimed to determine the per capita contribution of fecal sewage (Cp) in two rural households in the state of Goiás, Brazil. Measurements were taken during the dry season in two houses located in quilombola communities, with different numbers of inhabitants (five and one, respectively). For data collection, a volumetric water meter (with a nominal flow rate of 1.5 m3/h) was installed on the water supply line to the toilet(s) of each residence. The results indicated a variation in Cp from 7.04 to 32.35 L/capita/day, with averages of 12.66 and 22.05 L/capita/day. These values are within the range found in similar studies for rural areas, with a minimum value of 9.9 L/capita/day and a maximum of 33.0 L/capita/day. Comparing the obtained data with the values estimated in the literature, it was observed that direct measurements tend to be more accurate. This finding highlights the importance of direct measurements to reduce or avoid construction costs. Therefore, it is recommended to expand measurements to include households with different demographic and geographic characteristics, also considering meteorological data, in order to obtain more representative results.
Main methods of regionalization of minimum flows, advantages and disadvantages and their limitations: a review
(2025) Vaca Castañeda, Walter Yuliann; Vasco, Joel Roberto Guimarães; Basso, Raviel Eurico
Estimating surface runoff in ungauged basins is important for planning and managing water resources, as well as for developing civil and environmental projects. Within the estimation of surface runoff are the minimum flows, which are important for assessing water availability and the possibility of granting water resources. To estimate surface runoff in ungauged basins, regionalization is a technique that has been used and consists of transferring variables, functions and/or parameters from gauged basins to the ungauged basin. This study reviews the minimum flow regionalization methods used in studies published between 2015 and 2023 in the CAPES, Scielo, Scopus and Web of Science databases. The regionalization methods were grouped according to their approach, namely the regionalization of hydrological signatures and the regionalization of hydrological model parameters. Most studies focused on regionalizing hydrological signatures, particularly minimum flows and flow duration curves. For regionalizing hydrological model parameters, common approaches included spatial proximity, physical similarity and regression techniques. Some methods can estimate the flow time series at the location of interest, which can be an advantage for estimating different statistics from the data; other methods focus on estimating a specific flow statistic. Most methods require several gauged basins in their study area to obtain reliable estimates of minimum flows in ungauged basins. The study discusses the advantages, disadvantages and limitations of each method.
Wastewater treatment with geotextile filters: the role in permeability and pollutant control
(2025) Morais, Maria Vitoria; Marchiori, Leonardo; Sátiro, Josivaldo Rodrigues; Albuquerque, Antonio João Carvalho de; Cavaleiro, Victor
The application of geotextiles as filter materials in various systems, such as biofilters, wetlands, and wastewater treatment plants, has grown significantly in recent years. The ability of these materials to support biofilm growth makes them ideal for the removal of organic and inorganic contaminants present in wastewater. The objective of this research was to analyze clogging through variations in permeability, using column tests for 80 days with two types of nonwoven geotextiles with different grammages (GT120 and GT300), as well as to study the efficiency in the removal of organic matter. A synthetic wastewater was used, allowing the specific observation of biological clogging and the treatment carried out exclusively by microorganisms. The results indicated that bioclogging was not a significant factor within the experimental period. Through the mass test, a continuous increase in biofilm growth over time was observed for both geotextiles. For scanning electron microscopic (SEM) images, GT300 presented a larger biofilm area. A higher removal of COD (80%), N (52%), and P (36%) by microorganisms present in GT300 was found, which appears to be associated with its greater thickness and weight. The higher mesh density provides a larger area for the growth of microorganisms, allowing a greater amount of biomass to establish itself and contributing to the efficient removal of pollutants. These findings highlight the potential of using geotextile filters in wastewater treatment applications, where biofilm growth can positively contribute to contaminant removal without immediately compromising permeability.
Hydraulic transient analysis with the Smoothed Particle Hydrodynamics method coupled with unsteady friction model
(2025) Pamplona, Almério José Venâncio Pains Soares; Fernandes Júnior, José; Vasco, Joel Roberto Guimaraes; Nascimento, Andreia Aoyagui
This study employs the Smoothed Particle Hydrodynamics (SPH) method to investigate hydraulic transient phenomena in pipelines. The Corrected SPH (CSPH) technique effectively addresses domain support boundary imbalances, while the introduction of artificial viscosity suppresses spurious oscillations. A thorough assessment of unsteady friction models underscores their accuracy, showing the model based on two empirical coefficients — Kx , influencing the pressure wave damping ratio, and Kt , which governs pressure wave celerity — as the best among the unsteady friction models. The research optimizes critical parameters to minimize discrepancies between numerical simulations and experimental outcomes, revealing the significant effects of coefficients Kx and Kt on the accuracy of simulation responses. Furthermore, the study highlights the importance of Δx , the initial particle spacing, alongside the number of particles, to enhance both accuracy and stability in simulations. The proposed methodology demonstrates promising capabilities in simulating hydraulic transients, offering valuable insights for more precise modeling of fluid dynamics phenomena.
Removal of anionic surfactant in a sequential batch fluidized bed biological reactor filled with polymeric hydrochar
(2025) Silveira, Jéssica Rodrigues; Cuba Teran, Francisco Javier; Oliveira, Sérgio Botelho de
Biological fluidized bed systems can be used to treat effluent contaminated with linear alkylbenzene sulfonate (LAS) and can also be made up of support materials produced from spent ion exchange resin residues. Therefore, the objective of this study was to evaluate the removal of anionic surfactants, specifically LAS, in a fluidized bed system filled with polymeric hydrochar and a consortium of microorganisms. For this purpose, the methodology was developed in the following phases: (I) production and characterization of the support medium; (II) implementation of the system in sequential batches and hydrodynamic tests; (III) inoculation, synthetic substrate supplementation, and adaptation of the inoculum to the system’s LAS in sequential batches; and (IV) operation of the system in sequential batches to determine the LAS manipulation kinetics for three initial LAS concentrations from 17.51 to 41.89 mg L-1. In phase I, polymeric hydrochar was obtained with an average diameter of 0.715 mm, an acidic surface, a low specific surface area, high sphericity, and characteristics of a nonporous or macroporous solid. The hydrodynamic tests resulted in a minimum fluidization velocity of 0.49 cm-1 in phase II. For the biological treatment system, the inoculation, feeding, and adaptation trials were extended for 29 days in Phase III. From the LAS treatment in the system in sequential batches, in Phase IV, removal efficiencies greater than 80.0% were obtained for both concentrations evaluated after 48 h of operation, and the degradation rate coefficients (kLAS) decreased with increasing LAS concentration in the system.
Pasture degradation estimates through field data in the State of Goiás, Brazil
(2025) Teles, Nathalia Monteiro; Mesquita, Vinicius Vieira; Baumann, Luis Rodrigo Fernandes; Silva, Wilton Ladeira da; Andrade, Ana Carolina do Couto; Ferreira Junior, Laerte Guimarães
Grasslands and pastures play a critical role in global food security, biodiversity, and ecosystem services, particularly in tropical regions where they serve as the primary base for livestock production. However, these areas are increasingly vulnerable to degradation due to poor management practices, as observed in the Cerrado biome. This study focuses on pastures in Goiás, a state located in central-western Brazil, which relies heavily on pastures for its agricultural economy. We present a comprehensive field-based assessment of pasture degradation in Goiás, aiming to estimate the area of degraded pasture according to three categories: non-degraded, in process of degradation, and severely degraded. A three-stage cluster sampling design was employed to evaluate 460 field points, incorporating visual assessments of key variables using the novel Pasture Assessment Score (PAS). The sample size was determined to achieve a maximum expected standard error of 4.47% for the estimated proportion of pasture area across the three degradation levels, calculated using the Monte Carlo method. The scores were analyzed using Multiple Correspondence Analysis (MCA) to reduce dimensionality and identify clusters corresponding to degradation levels, which were modeled using Decision Trees. The results revealed that 39.35% (SE = 3.92%) of the pasture area in Goiás was classified as non-degraded, 31.98% (SE = 2.66%) as being in process of degradation, and 28.67% (SE = 3.64%) as severely degraded. These findings underscore the need for targeted management strategies and enhanced monitoring frameworks integrating field-based assessments with remote sensing data to support sustainable pasture management.
Water quality dynamics in cyanobacterial control in Brazilian Cerrado reservoir
(2025) Salgado, Aline de Arvelos; Santos, Kamila Almeida dos; Reis, Guilherme da Cruz dos; Basso, Raviel Eurico; Formiga, Klebber Teodomiro Martins
Understanding cyanobacterial dominance in tropical reservoirs is crucial for water management. This study examined the dynamics of water quality in the João Leite Reservoir, situated in the Brazilian Cerrado, utilising 30 months of monitoring data from five sites. Physical, chemical, and biological parameters, including fluorometric chlorophyll-a, using multivariate statistics (Cluster Analysis, Principal Component Analysis, PCA; Canonical Correlation Analysis, CCA), were analysed alongside the Trophic State Index (TSI). Results showed temporal variations exceeded spatial differences. Cyanobacteria were dominant despite generally low nutrient levels and an oligotrophic TSI classification. Principal Component Analysis revealed that temperature is strongly associated with cyanobacterial density. However, Canonical Correspondence Analysis and correlations revealed limited direct statistical influence of measured physicochemical parameters, including nutrients, on cyanobacterial abundance. Findings suggest that in this warm, tropical system, high temperatures combined with stable hydrodynamics, resulting from long hydraulic retention times (>180 days), likely facilitate cyanobacterial success, overriding direct nutrient limitation.
Impact of inoculum on domestic wastewater treatment in high-rate ponds in pilot-scale: assessment of organic matter and nutrients removal, biomass growth, and content
(2025-03) Sátiro, Josivaldo Rodrigues; Santos Neto, Antônio dos; Ferreira, Jucélia Tavares; Marinho, Idayana da Costa; Magnus, Bruna Scandolara; Kato, Mario Takayuki; Albuquerque, Antonio João Carvalho de; Santos, Maria de Lourdes Florêncio dos
Discharging untreated wastewater deteriorates water bodies, but biological treatment methods can mitigate this by reducing organic matter, nutrients, and phosphorus. Systems using microalgae-bacteria consortia are promising nature-based solutions (NbS) that require no artificial aeration and can produce valuable products. This study, conducted on a pilot scale with domestic wastewater, involved two high-rate ponds (HRP1 and HRP2) with a depth of 0.30 m and lengths of 6.0 m. While HRP1 was not inoculated, HRP2 received activated sludge, and both were operated in two sequential batches followed by continuous operation with a four-day hydraulic detention time. After 20 days, biomass and system stabilization were primarily observed in HRP2, which achieved total nitrogen removal of 84.2 %, phosphorus removal of 63.7 %, and organic matter removal of 74.7 %. The inoculated pond showed increased stability and sedimentation capacity, with average volatile suspended solids of 152.75 ± 120.53 mg/L, a flocculation efficiency exceeding 90 %, and a sludge volume index of 19.83 ± 28.54 mL/g. Chlorophyll-a concentrations were higher in HRP2 (0.84 ± 0.48 mg/L), indicating higher algal biomass. Protein concentrations were 98.86 ± 47.78 mg/gVSS in HRP2, while carbohydrate concentrations averaged 67.87 ± 135.07 mg/gVSS, slightly superior for HRP2. Additionally, HRP2 demonstrated a lipid content of 23.03 %, attributed to a dominant Chlorella sp. presence. These findings underscore the need to optimize operational parameters and microbial consortia for effective biomass production and resource recovery in HRPs. Such low-cost NbS contribute to pollution control and align with the UN's sustainability objectives (SDGs) 3, 6, 11, 13, and 14.

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