Doutorado em Engenharia Ambiental
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- ItemFlow variability and stochastic dispersion in street networks(Universidade Federal do Espírito Santo, 2025-02-25) Klippel, Karine; Coeceal, Omduth ; https://orcid.org/0000-0003-0705-6755 ; Auerswald, Torsten; https://orcid.org/0009-0007-5827-5487; Reis Júnior, Neyval Costa; https://orcid.org/0000-0002-6159-4063; http://lattes.cnpq.br/4944106074149720; Goulart, Elisa Valentim ; https://orcid.org/0000-0002-0051-0778 ; http://lattes.cnpq.br/0014236670973457; https://orcid.org/0000-0003-4524-2006 ; http://lattes.cnpq.br/8819752005217100 ; Furieri Bruno ; https://orcid.org/0000-0002-9736-0250; http://lattes.cnpq.br/6585455298349085 ; Santos, Jane Meri ; https://orcid.org/0000-0003-3933-2849; http://lattes.cnpq.br/0120226021957540; Soulhac, Lionel ; https://orcid.org/0000-0003-0358-3486; http://lattes.cnpq.br/4944106074149720; Carpentieri, Matteo ; https://orcid.org/0000-0002-8968-9339This study investigates flow variability and stochasticity across different scales and their impact on passive scalar dispersion in a street network. Direct numerical simulations (DNS) data from the DIPLOS project were used for a regular array of rectangular buildings with inflow at a 45° angle to the streets. Puff and continuous sources were positioned near the ground in three locations: short street (S1), intersection (S2), and long street (S3). Simulations were compared to wind tunnel (WT) measurements for flow and scalar dispersion from source S2. The research addresses: (i) street-network scale variability, focusing on sources of flow variability, their effects on scalar releases, and uncertainties from experimental setups; (ii) intersection-scale variability, analysing flow switching and its influence on continuous releases; and (iii) concentration fluctuations, investigating spatial dependence and statistical modelling. Key findings include: (i) flow variability was observed at multiple scales, from small-scale intra-street variations linked to local flow topology, to inter-street differences, street-network-scale variability, and larger-scale variations associated with above-canopy structures. DNS and WT comparisons agreed for flow statistics and mean concentration profiles in continuous releases but differed significantly for puff releases, attributed to flow variability, setup discrepancies, and experimental uncertainties. An implication of these results is that for singular events like accidental releases, characterizing uncertainties is more meaningful than computing ensemble averages. (ii) At intersections, bistable horizontal wind direction switching was observed near the ground (z = 0.125h and z= 0.25h), with peaks at approximately -10° and 110°, offset from the expected alignment with the short (0°) and long (90°) streets. The average switching timescale was 10.5T, where T is the eddy turnover time, with waiting times of 5T and 3T per state. Strong wind direction correlation in diagonally neighbouring intersections was observed with a time lag below 1T. Wind direction switching significantly influenced scalar concentrations from continuous sources, with nearfield anticorrelation in short streets and weaker far-field correlations, highlighting the role of street-network structures and mixing processes. (iii) Clustering analysis of concentration fluctuations identified three regions within the plume with distinct distributions: (1) plume edge, with exponential-like distributions, high intermittency, and extreme skewness and kurtosis; (2) transition region, with asymmetric distributions and reduced intermittency; and (3) plume centre, exhibiting Gaussian-like distributions with negligible intermittency and near-zero skewness. Gamma, Beta, Lognormal, and Weibull distributions were evaluated for modelling these fluctuations. Gamma was the most consistent, capturing distribution shapes and performing well for the 50th and 98th percentiles of the inverse cumulative density function. While Gamma excelled in variance predictions in high-fluctuation regions (cluster 1) and Beta performed better for skewness and kurtosis in low-fluctuation areas (cluster 3), all models struggled with higherorder moments in cluster 1, highlighting challenges in modelling fat-tailed distributions.
- ItemSistema de suporte à decisão para subsídio à otimização de localização de pontos de lançamento de efluentes, à estimativa de eficiências de tratamento e à análise de solicitações de outorga de diluição em rios(Universidade Federal do Espírito Santo, 2025-12-03) Fortunato, Tatiana Candeia da Silva; Mendonça, Antônio Sérgio Ferreira; https://orcid.org/0000-0003-4273-0266; http://lattes.cnpq.br/9841888526169409; https://orcid.org/0000-0001-7938-1165; http://lattes.cnpq.br/8772001332861341; Reis, José Antônio Tosta dos; https://orcid.org/0000-0001-9916-1469; http://lattes.cnpq.br/7828468159099998; Buarque, Diogo Costa; https://orcid.org/0000-0003-2698-520X; http://lattes.cnpq.br/8616432679482558; Silva, Fernando das Graças Braga da; https://orcid.org/0000-0002-3803-2257; http://lattes.cnpq.br/4077250337099004; Caiado, Marco Aurélio Costa; https://orcid.org/0000-0002-2658-3916; http://lattes.cnpq.br/7949976625744034The main objective of this thesis was to develop a methodology to support decision-making related to the location of effluent discharges points, the definition of treatment efficiencies, and the analysis of respective requests for dilution permits in rivers. To this end, the QUAL-UFMG water quality model was integrated with a metaheuristic optimization technique (Genetic Algorithm) in the form of a decision support system (DSS). The system was implemented in the Python programming language, reproducing the mathematical formulations and conceptual and computational structures of the model, incorporating a database and communication interface. The interface allows for input data entry and graphical visualization of results, facilitating the analysis of the most suitable locations for effluent disposal, considering the hydraulic characteristics, self purification capacity, and classification classes of the water bodies under consideration. Additionally, two optimization models with distinct objectives were integrated into the system: (i) minimizing the sum of treatment efficiencies and (ii) minimizing inequality between effluent discharges, aiming to meet water quality standards for dissolved oxygen (DO) and biochemical oxygen demand (BOD) standards. The main reach of the Pardo River was selected for the application of the system, located in the state of Espírito Santo, Brazil. Based on hydrological and water quality information from this basin, three fictitious scenarios were defined, considering different framing classes, and the responses for each simulated scenario were evaluated. Based on the set of solutions obtained in the Pareto front for each simulated scenario, the relevance and applicability of the developed system are highlighted as a support tool for decisions related to the appropriate siting of effluent discharge points, compliance with water quality standards, determination of dilution flows, identification of the minimum total treatment efficiency, and equity among discharges, associated with the objective functions employed.
- ItemMudanças climáticas e seus impactos no fluxo de sedimentos da bacia amazônica(Universidade Federal do Espírito Santo, 2025-10-20) Föeger, Lizandra Broseghini; Buarque, Diogo Costa; https://orcid.org/0000-0003-2698-520X; http://lattes.cnpq.br/8616432679482558; https://orcid.org/0000-0002-9823-8994; http://lattes.cnpq.br/8970031007022234; Mendonça, Antônio Sérgio Ferreira; https://orcid.org/0000-0003-4273-0266; http://lattes.cnpq.br/9841888526169409; Oliveira, Paulo Tarso Sanches de; https://orcid.org/0000-0003-2806-0083; http://lattes.cnpq.br/5149856612324019; Pontes, Paulo Rógenes Monteiro; https://orcid.org/0000-0002-8172-7820; http://lattes.cnpq.br/8571693032057372; Brêda, João Paulo Lyra Fialho; https://orcid.org/0000-0002-8360-1308; http://lattes.cnpq.br/6946628555597087This study investigates the impacts of climate change on sediment fluxes in the Amazon Basin, the world's largest hydrographic basin and one of the planet's most important biomes, in light of the scarcity of studies that integrate the most recent climate projections with hydro-sedimentological models for the basin. For this purpose, the MGB-SED model was applied on a daily scale, calibrated and validated with observed hydrological and sediment data, and forced with CMIP6 climate projections from five models of the NEX-GDDP-CMIP6 ensemble, under two emission scenarios (SSP2-4.5 and SSP5-8.5), for the future period (2015 – 2100). The incorporation of seasonality as a central axis of analysis, distinguishing between dry and wet periods, allowed for the identification of interannual patterns of agreement and disagreement between streamflow and sediment discharge that might not be captured by conventional annual approaches. The results indicate a general trend of reduced streamflow, especially during the dry season and under the high-emission scenario SSP5-8.5, highlighting a greater vulnerability of water availability in the basin. In contrast, the analysis of solid discharge showed heterogeneous responses, with projected increases particularly during the wet season and in scenarios with higher radiative forcing. The coexistence of the trend of decreasing streamflow and increasing solid discharge in several sub-basins highlights the nonlinear and spatially variable nature of the hydro-sedimentological responses to climatic forcings. The study provided a calibrated and validated hydro-sedimentological model for the Amazon Basin, through which streamflow and sediment flux projections were quantified in future scenarios, offering unprecedented insights into the trends of erosion, transport, and sediment deposition throughout the end of the century. Such results can inform evidence-based decision-making, allowing for the identification of critical areas of potential increase or decrease in sediment load.
- ItemAnálise experimental do escoamento no interior de um túnel de vento portátil utilizado para estimativa de emissões de gases odorantes a partir de superfícies líquidas passivas(Universidade Federal do Espírito Santo, 2025-10-31) Lima, Pâmela Rossoni; Paula, Igor Braga de; https://orcid.org/0000-0002-1149-0784; http://lattes.cnpq.br/1814779476910411 ; Santos, Jane Méri; https://orcid.org/0000-0003-3933-2849; http://lattes.cnpq.br/0120226021957540; https://orcid.org/0000-0002-4538-9297; http://lattes.cnpq.br/5148878822357015; Reis Junior, Neyval Costa; https://orcid.org/0000-0002-6159-4063; http://lattes.cnpq.br/4944106074149720; Furieri, Bruno; https://orcid.org/0000-0002-9736-0250; http://lattes.cnpq.br/6585455298349085; Martins, Fábio Jessen Werneck de Almeida; https://orcid.org/0000-0002-5841-4228; http://lattes.cnpq.br/8935935661464997; Moreira, Davidson Martins; https://orcid.org/0000-0002-0902-5218; http://lattes.cnpq.br/2331953711858907Wastewater treatment plants (WWTPs) are significant sources of odorous gases in urban areas, potentially affecting the well-being and quality of life of nearby populations. Estimating emissions of these gases is a key step in developing control strategies and assessing their environmental impact. Stabilization ponds and primary and secondary settling tanks, characterized by passive liquid surfaces, are among the main emission sources in WWTPs. The Portable Wind Tunnel (PWT) is a device designed to enclose the liquid surface and directly measure emissions from passive liquid surfaces exposed to the atmosphere, as it has the potential to reproduce atmospheric flow conditions over the surface. However, the literature on the physical understanding of the flow within the PWT and the mass transfer phenomena occurring inside the apparatus remains limited. The friction velocity (𝑢∗) at the surface inside the device is a key parameter to ensure that the emission rate measured by the PWT is comparable to that from an open passive liquid surface under atmospheric flow conditions. Therefore, the aim of this study was to investigate the flow characteristics within a portable wind tunnel, evaluating its ability to reproduce representative aerodynamic conditions and its influence on mass transfer over liquid surfaces under turbulent flow. The specific objectives included analyzing the velocity fields inside the device, identifying the flow regime and the need for flow conditioners, and evaluating the influence of operating flow rate on the surface friction velocity through boundary layer analysis within the PWT. To achieve these goals, laboratory experiments were conducted to measure the velocity field inside the PWT using Particle Image Velocimetry (PIV). The results revealed an initially non-uniform flow pattern with extensive recirculation, which was mitigated by installing flow conditioners. At low velocities, the flow was laminar. Increasing the flow rate in the test section resulted in a fully developed turbulent flow analogous to that over a flat plate, allowing the development of a mathematical model to estimate friction velocity under the tested operating conditions. The 𝑢∗ values obtained in the PWT were compared with estimates from an empirical model for passive liquid surfaces in WWTPs. It was observed that, within specific ranges, the PWT is capable of reproducing 𝑢∗ values similar to those found in real wastewater treatment plant scenarios, reaching a maximum compatibility of 23%. Since most values estimated by the empirical model were below the experimental range achieved in the PWT, adjustments allowing operation at lower friction velocities under turbulent flow could significantly improve representativeness, reaching up to 90% compatibility in certain cases. Although the PWT showed partial compatibility with the typical 𝑢∗ values observed in WWTPs, some experimental limitations must be considered. The friction velocities observed in the device were associated with a rigid, smooth surface, unlike the deformable liquid surfaces typical of real WWTP conditions. Moreover, although wave formation was not observed in the wave verification test conducted in a water tank, literature suggests that wave development would be expected for the tested 𝑢∗ range. This discrepancy may be attributed to the short length of the PWT and the influence of sidewalls. Additionally, based on the 𝑢∗ values estimated by the empirical model, a sensitivity analysis was performed using the main models commonly applied to estimate emissions in WWTPs, considering odorous compounds with distinct volatilization patterns. It was found that neglecting the surrounding roughness can lead to significant overestimations of the global mass transfer coefficient (𝐾𝐿), reaching up to 40% for compounds dominated by the liquid phase and up to 33% for those dominated by the gas phase or both. These findings underscore the importance of adequately accounting for aerodynamic surface roughness in emission assessments of WWTPs.
- ItemEnergy source in the heavy freight railway sector: a life cycle assessment (LCA)(Universidade Federal do Espírito Santo, 2025-08-25) Carvalhaes, Bernardo Bicalho; Medeiros, Diego Lima; https://orcid.org/0000-0002-6332-7217; http://lattes.cnpq.br/6574996299327565 ; Gama, João Luiz Calmon Nogueira da; https://orcid.org/0000-0002-3054-4784; http://lattes.cnpq.br/7619015734946549; https://orcid.org/0000-0001-9343-8105; http://lattes.cnpq.br/4965820160936034 ; Bravo, Alencar Soares; http://lattes.cnpq.br/4319910381165850 ; Ramalho, José Carlos Martins; https://orcid.org/0000-0003-4579-6009; http://lattes.cnpq.br/7380247155655477 ; Pinho, Giusilene Costa de Souza; https://orcid.org/0000-0002-4586-7092; http://lattes.cnpq.br/2215987864333281; Rosa, Rodrigo de Alvarenga; https://orcid.org/0000-0003-0841-514X; http://lattes.cnpq.br/7706827408886021This study conducts a review of several articles inside the context of railroads, where the life cycle assessment methodology (LCA) is applied. Using the ProKnow-C methodology, seven review and 85 original papers applying the LCA methodology to railroads are analyzed, and several important gaps were identified, mainly concerning the lack of disclosure of information about parameters, software and other important decisions made during the works that would allow other researchers to replicate the results in order to compare them to other railroads or different circumstances. Currently, there are no ISO standards addressing the LCA of railroads, so this work seeks to provide an initial set of guidelines for such a norm, thus facilitating the elaboration of such a norm and providing support and direction for researchers in the field until a norm can be established.