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Percorrer Teses de Mestrado ESTiG por Objetivos de Desenvolvimento Sustentável (ODS) "06:Água Potável e Saneamento"
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- Aproveitamento de águas pluviais em edifícios escolares com coberturas verdes ou convencionais: contributos para uma drenagem urbana sustentávelPublication . Chen, Sanlira Shuting; Silva, Flora; Antão-Geraldes, Ana Maria; Jabur, Andrea SartoriA água é um recurso essencial para a vida e o desenvolvimento sustentável, mas a sua escassez, agravada pelo crescimento populacional, urbanização e mudanças climáticas, representa um desafio global. Soluções como os sistemas de aproveitamento de águas pluviais (SAAP) e as coberturas verdes (CV) emergem como estratégias promissoras promovendo benefícios ambientais, sociais e econômicos. Assim, este estudo avaliou o consumo de água em dois edifícios escolares em Bragança (Portugal), propondo medidas de eficiência hídrica por meio da implementação de SAAP, CV, integração dessas tecnologias e substituição das torneiras existentes por modelos mais eficientes. O Centro Escolar de Santa Maria (CESMaria) consome 2.820,2 m³/ano de água no período com rega, e o Centro Escolar da Sé (CESé), 5.260,5 m³/ano. O Cenário 1 (substituição de torneiras) mostrou-se a opção mais viável a curto prazo, com retorno do investimento em 1 ano, reduzindo o consumo de água em aproximadamente 30% e gerando economias anuais de cerca de 3.700 € + IVA em ambos os edifícios escolares. Já o Cenário 3 (combinação de torneiras eficientes e SAAP em coberturas convencionais (CC)), mostrou-se ideal a longo prazo, com reduções de consumo de até 60% e economias anuais superiores a 7.000 € + IVA, com retorno do investimento em 8 (CESMaria) e 7 anos (CESé). Outros cenários, que variam a proporção de CV e combinam SAAP com torneiras eficientes, também apresentaram reduções de consumo (até 58,83% no CESMaria e 60,73% no CESé) e economias financeiras (25%-60%). As CC mostraram maior eficiência na captação de água, com 93,84% de aproveitamento no CESMaria e 94,65% no CESé, utilizando reservatórios de 60 m³ e 70 m³, respectivamente. Já as CV’s reduziram a captação para 70%-90% devido à retenção de água pela vegetação, retendo entre 18,8% e 37,5% da água da chuva. Logo, as propostas promovem gestão hídrica sustentável, alinhando-se a objetivos econômicos e ambientais.
- Development of geopolymer-carbon composite for wastewater treatmentPublication . Silva, Lívia Firmani; Gomes, Hélder; Pereira, Edilaine ReginaThe quality of wastewater treatment and the discharge of treated effluents remain major environmental issues, particularly due to the release of contaminants of emerging concern into aquatic environments as a result of insufficient tertiary treatment in wastewater treatment plants. Among these contaminants of emerging concern, pharmaceuticals such as carbamazepine, are frequently detected in wastewater and poses potential risks to water quality. In this context, the present study investigates the development of geopolymer and geopolymer-carbon composite subjected to a zeolitization process, produced from waste-derived materials. Fly ash was used as the primary precursor for geopolymer synthesis, while activated carbon was obtained from grape pomace. Comprehensive characterization was performed to assess the composition, structure, and surface properties of the synthesized materials. X-ray diffraction analysis revealed the presence of major crystalline phases, including quartz, hematite, and calcite, as well as the formation of zeolitic phases (Na-faujasite) in GP_HT2.0, whereas GP_AC_HT2.0 exhibited only calcite and gehlenite phases. Fourier Transform Infrared Spectroscopy spectra confirmed the presence of Si–O–T groups in the inorganic (FA, GP_M, GP_ HT1.0, GP_ HT1.5, GP _HT2.0, and GP_HT2.5) materials and carbon-related (–CH₂ and –CH₃ groups, C–O and C–O–C) bonds in the organic (WGP, AC_WGP, GP _AC, and GP _AC_HT2.0) materials. Additionally, acid–base characterization demonstrated the high basicity of all samples. BET analysis revealed a specific surface area of 427 m² g⁻¹ for AC, 30 m² g⁻¹ for GP_M, 181 m² g⁻¹ for GP _HT2.0, 48 m² g⁻¹ for GP_AC, and 139 m² g⁻¹ for GP_AC_HT2.0. Equilibrium analysis showed that the Langmuir model effectively described the adsorption process, indicating favorable conditions and strong affinity between the adsorbents and the adsorbate. Kinetic studies confirmed that all materials followed a pseudo-second-order model, the maximum adsorption capacities were determined as 4.2, 29.4, 39.7, and 30.6 mg g⁻¹ for GP_M, GP _HT2.0, GP_AC, and GP_AC_HT2.0, respectively.
- Optimizing biogas production via ozone sludge pretreatmentPublication . Alqudah, Safaa Ahmad Mustafa; Martins, RamiroAnaerobic digestion (AD) is the preferred method for handling wastewater sludge while producing renewable energy in the form of biogas. However, this process often occurs during the hydrolysis phase, which can prevent the system from working at maximum efficiency. This study examined the effect of ozone pre-treatment on methane generation from municipal sludge during mesophilic batch digestion. Ozone was applied at concentrations of 0%, 5%, and 10% for exposure times of 30, 60, and 90 s, respectively. A series of anaerobic co-digestion experiments was then conducted using different inoculum-tosubstrate (I/S) ratios of 1.0, 1.5, and 2.0. Methane production was continuously monitored using the AMPTS II system. The methane yield was 736 NmL CH4 g-1 VS at an ozone concentration of 4.41 L min-1. The Buswell–Mueller equation was applied to estimate the theoretical biochemical methane potential (TBMP), resulting in a value of approximately 517 mL CH₄ per gram of volatile solids (VS). Kinetic modeling using the modified Gompertz equation showed faster methane production rates and reduced lag times under the optimized pretreatment conditions. Overall, the data suggest that ozone pretreatment, when carefully controlled, can significantly improve sludge biodegradability and enhance biogas yields, indicating a promising method for increasing energy recovery in wastewater treatment systems. Furthermore, a comparative evaluation of four kinetic models (Gompertz, Logistic, Transference, and Cone) was conducted to identify the most suitable approach for describing biogas production kinetics under ozone pretreatment. Although all models provided statistically robust fits, the Logistic and Gompertz models demonstrated slightly superior consistency and interpretability across the range of experimental conditions. This careful model selection not only improved the reliability of methane yield predictions but also supported more informed process optimization. Overall, these findings emphasize that integrating robust kinetic modeling with innovative pretreatment strategies can significantly enhance biogas yield and process efficiency, offering valuable insights into advancing sustainable energy recovery from municipal sludge.