https://ri.ufs.br/jspui/handle/riufs/2494 2026-10-31T08:02:46Z 2026-10-31T08:02:46Z Santos, Hellen Karine Sales dos https://ri.ufs.br/jspui/handle/riufs/26216 2026-10-28T14:02:44Z 2025-06-25T00:00:00Z

Title: Avaliação técnica, energética, econômica e ambiental do aproveitamento energético de biogás a partir da biodigestão anaeróbia de lodo de estações de tratamento de esgotos em Sergipe Authors: Santos, Hellen Karine Sales dos Abstract: The sludge generated in sewage treatment is increasing in production as collection and treatment services advance. Sewage sludge management has associated costs, and anaerobic digestion is a positive approach that adds sustainable management and produces biogas, which can be used for electricity generation. The objective of this study is to evaluate the energy use of sludge generated at the following WWTPs: ERQ Sul, ERQ Oeste, ETE Orlando, and ETE Barra. To achieve this goal, the research methodology involved collecting sludge and sewage samples, analyzing the parameters SS, SV, ST, and SF from the first sludge samples, as well as temperature, pH, and COD from the second samples. The data were then statistically processed, and sludge production was estimated. The work also covered technical, energy, economic, and environmental analysis. The first involved the design of a biodigester to receive and anaerobically digest the sludge generated at the WWTPs in question and a biogas utilization system to generate energy. The second involved calculating the energy balance and savings from the energy supplied by biogas. The third involved calculating the net present value and payback period. The latter covered the calculation of avoided greenhouse gas emissions. In the technical analysis, the biodigesters designed were cylindrical with conical lids and bottoms, all made of reinforced concrete, for two scenarios: one in which it receives sludge from all stations, with a sludge flow of 156.7 m³/day and production of 789.6 m³/day of biogas (BC1), and another that receives sludge only from ERQ Sul (BC2), with a flow of 131.1 m³/day of sludge and generation of 646.3 m³/day of biogas. In the energy analysis, both digesters are able to meet the demand of only the Orlando WWTP or ERQ Sul, with a positive energy balance. In the economic analysis, the two biodigesters pointed to economic unfeasibility with a discounted payback period of 16 years, however, the energy and environmental gains that the project can add must also be considered. Finally, the environmental analysis found a reduction in greenhouse gas (GHG) emissions, with the caveat of ensuring the system is airtight to prevent gas leaks. Thus, the energy use from sewage sludge in Sergipe was evaluated in technical, energy, economic, and environmental terms, highlighting an opportunity to transform the challenge of sludge management into an energy-efficient alternative.

2025-06-25T00:00:00Z Carvalho, João Marcos Lima https://ri.ufs.br/jspui/handle/riufs/26214 2026-10-28T13:48:07Z 2026-08-28T00:00:00Z

Title: Análise da incorporação de CO2 em placa cimentícia têxtil Authors: Carvalho, João Marcos Lima Abstract: The growing concern about the environmental impacts caused by carbon dioxide (CO₂) emissions from the cement industry has driven the development of sustainable and efficient materials. Portland cement, the main binder in concrete and cementitious boards, is responsible for a significant share of global CO₂ emissions. In this context, the present study proposes to investigate alternatives that combine technical performance with a reduced carbon footprint through the use of textile reinforcements in flat cementitious boards subjected to accelerated carbonation. The general objective of this work is to evaluate CO₂ uptake through carbonation under different exposure conditions in flat cementitious boards reinforced with nonwoven fabric and alkali-resistant glass fabric, in comparison with boards reinforced with synthetic PVA fibers, analyzing the differences in physical, mechanical, and microstructural behavior, as well as in eco-efficiency indicators. The experimental methodology consists of material characterization (particle size distribution by laser diffraction, X-Ray Fluorescence, X-Ray Diffraction, specific mass, and Scanning Electron Microscopy), production of samples in batches using molds with internal dimensions of 29.5 × 16 × 1 cm, and natural carbonation (NC) and chamber carbonation (CC), both with controlled relative humidity and temperature, and with the CO₂ concentration set at 5%. The boards feature two layers of fabric interlaid within the cementitious matrix (Nonwoven Fabric Board (NFB) and Alkali-Resistant Glass Fabric Board (ARGB)). The sample groups were produced and subjected to physical tests (porosity, densities, and dimensional variation due to carbonation), mechanical tests (three-point flexural strength), microstructural tests (digital microscopy, thermogravimetry, carbonation depth, and gravimetry by mass loss in a muffle furnace), and eco-efficiency indicators (binder-flexural intensity, carbon-flexural intensity, and equivalent carbon-flexural intensity balance). The results showed that the NFB exhibited higher porosity and water absorption, associated with a greater advance of the carbonation front, reaching 0.79 mm at 14 days under NC and 0.87 mm under CC. CO₂ uptake at 28 days was also higher in the NFB, reaching 1.70% under NC and 0.88% under CC. In contrast, the ARGB showed a lower carbonation depth, associated with its lower porosity, and stood out for its better mechanical performance and lower eco-efficiency across the three proposed indicators. It is concluded that the type of reinforcement exerts a significant influence on the interaction between CO₂ transport, microstructure, and mechanical performance. The NFB showed greater potential for CO₂ mineralization under the conditions evaluated, while the ARGB presented the best balance between structural performance and eco-efficiency. CO₂ uptake was still insufficient to offset the emissions associated with production during the period evaluated, indicating the need for longer exposure times to better assess the carbonation potential of the boards.

2026-08-28T00:00:00Z Chaves, Laísa Fontes Santiago https://ri.ufs.br/jspui/handle/riufs/26209 2026-10-02T20:04:00Z 2026-07-22T00:00:00Z

Title: Estudo do estado de conservação de fachadas históricas em Lagarto-SE: avaliação em exemplares religioso, institucional e residencial Authors: Chaves, Laísa Fontes Santiago Abstract: The conservation of built cultural heritage—particularly in inland towns—faces a disconnect between the recognition of its historical, aesthetic, and identity-related value and the actual implementation of safeguarding measures, a situation exacerbated by a scarcity of systematized technical studies. Against this backdrop, this dissertation aimed to assess the actual state of conservation of the rendered facades of historic buildings in Lagarto, Sergipe (SE), using an integrated approach that links architectural characteristics, construction techniques, constituent materials, and pathological manifestations. Three representative examples of distinct typologies, built between the 19th and early 20th centuries around the Praça da Matriz, were selected: the Colonial Residence at No. 175 (wattle-and-daub construction); the Church of Our Lady of the Rosary (Neo-Gothic style, stone masonry); and the former City Hall (stone masonry). The methodology comprised a literature and document review, architectural analysis, laboratory characterization of mortars (visual and petrographic analysis, particle size distribution, soluble salt testing, and X-ray diffraction), visual inspection with damage mapping, infrared thermography, and the application of the Conservation Status Indicator for Historic Building Facades (IDh). The results revealed a critical state of conservation across the evaluated group and allowed for the distinction of two material families—historic air-lime mortars (in the Residence and the Church) and contemporary cement-based repairs (in the City Hall)—as well as three predominant degradation mechanisms: structural (due to settlement) in the Residence; physicochemical (due to rising damp and salinization) in the Church; and material incompatibility (due to non-conservative interventions) in the City Hall. The application of the IDh index confirmed this scenario, with values ranging from optimal (9.60% on the church's north façade) to very poor (776% at the Residence and up to 243% at City Hall), demonstrating that the most severe degradation is systematically associated with the replacement of original materials with rigid, impermeable cement-based mortars. It is concluded that an integrated technical diagnosis not only quantifies degradation but also identifies its root causes, providing a scientific basis for compatible interventions that respect the authenticity and integrity of Lagarto’s built heritage and inform future municipal preservation policies.

2026-07-22T00:00:00Z Santos, Rafael Freire https://ri.ufs.br/jspui/handle/riufs/26208 2026-10-02T19:44:00Z 2026-08-27T00:00:00Z

Title: Avaliação da eficiência energética segundo a INI-C da Biblioteca Pública Epiphânio Dória em Aracaju-SE Authors: Santos, Rafael Freire Abstract: Energy efficiency in public buildings is a topic of growing relevance, especially in buildings of historical and architectural value, in which system modernization must be reconciled with the preservation of their existing characteristics. In this context, the evaluation of lighting systems must reconcile energy consumption and the luminous quality of interior spaces. This research aims to evaluate the electric lighting system of the Epiphanio Dória Public Library (BPED), in Aracaju-SE, Brazil, according to the Simplified Method of the Inmetro Normative Instruction for the Energy Efficiency Classification of Commercial, Service, and Public Buildings (INI-C) and the Brazilian standard ABNT NBR ISO/CIE 8995-1, to verify the possibility of achieving Class A, and to propose improvements in energy and luminous performance. The research was developed in five stages: bibliographic and documentary review; architectural and lighting system survey; energy assessment according to INI-C; luminous performance assessment according to ABNT NBR ISO/CIE 8995-1; and proposition of an optimized scenario. The current scenario, although it reduces consumption by 86.7% compared to the reference condition, does not meet the INI-C lighting control eligibility criteria and remains classified as Class B. The proposed scenario (79.4% reduction) meets these criteria through independent circuits per room, achieves Class A, and increases compliance with ABNT NBR ISO/CIE 8995- 1 from 4.4% to 97.1% of the assessed rooms. It is concluded that the modernization is technically feasible and depends on the renewal of light sources, the redistribution of luminaires, and control strategies integrated with daylight.

2026-08-27T00:00:00Z