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Percorrer Escola Superior de Tecnologia e Gestão 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.
- Effects of extensive green roofs on rainwater drainage from a metalworking industry buildingPublication . Rodrigues, Rodrigues; Mazzer, Helton; Geraldes, Ana Maria; Silva, FloraThis study examines how extensive green roofs impact the sizing of the rainwater drainage system for a metalworking building in northeastern Portugal. If the roof, measuring approximately 4,700 m², is constructed of sheet metal, the calculated flow rate that must be drained is 5,860.51 L/min. In contrast, if the roof is green and extensive, the calculated flow rate drops to 3,255.84 L/min. This represents a 44.44% retention of rainwater, which necessitates changes in the components of the drainage system. Additionally, the green roof delays the release of unretained water into the urban drainage system, thereby contributing to sustainable urban drainage and helping to mitigate urban flooding.
- Implementação de medidas de eficiência hídrica e drenagem sustentável em edifícios escolares: impactos na conservação dos ecossistemas costeirosPublication . Sanlira Shuting Chen; Jabur, Andrea Sartori; Geraldes, Ana Maria; Silva, FloraOs ecossistemas costeiros e estuarinos estão interligados com os corpos hídricos de água doce, influenciando nos processos de sedimentação, oferta de nutrientes e os níveis de salinidade. No entanto, esse equilíbrio está sendo comprometido pelo aumento do consumo de água, urbanização desordenada e mudanças climáticas, resultando na redução dos recursos hídricos, perda de biodiversidade e alterações nos ciclos naturais. Diante disso, a adoção de medidas de eficiência hídrica torna-se urgentes para mitigar esses impactos, especialmente em edifícios públicos, como escolas, que demandam grandes volumes de água e são espaços estratégicos para a implementação de soluções sustentáveis. Portanto, este estudo analisou o impacto de medidas como sistemas de aproveitamento de águas pluviais (SAAP), coberturas verdes (CV), a integração dessas duas tecnologias e a substituição das torneiras por outros modelos mais eficientes em dois centros escolares (Centro Escolar de Santa Maria – CESMaria e Centro Escolar da Sé – CESé), localizados em Bragança – Portugal, tendo como objetivo principal a redução do consumo de água potável, aumentando a disponibilidade hídrica para os ecossistemas, promovendo sua conservação. Foram avaliados nove cenários, destacando-se dois: Cenário 1, focado na substituição das torneiras, mais viável a curto prazo, com retorno do investimento em um ano, apresentando redução de aproximadamente 30% no consumo de água e economia de cerca de 29% nos custos, em ambas escolas. Já o Cenário 3, que combina torneiras eficientes com SAAP em coberturas convencionais (CC), destacou-se a longo prazo, com redução estimada de 60% no consumo de água e economia de aproximadamente 60% nos custos, com retorno do investimento entre 7 (CESé) e 8 anos (CESMaria). Cenários que combinam SAAP, torneiras eficientes e diferentes proporções de coberturas verdes (50%-70%) também mostraram reduções no consumo (30-60%) e economias financeiras entre 25% e 60%. As CC apresentaram maior eficiência na captação de água, com 93,84% no CESMaria e 94,65% no CESé, enquanto as CV reduziram a captação para 70%-90% devido à retenção de água pela vegetação. As CV retiveram entre 18,8% e 37,5% da água da chuva, com volumes variando de 154,2 m3 a 362,0 m3. Conclui-se que a implementação de medidas de eficiência hídrica promove uma gestão sustentável dos recursos hídricos, alinhando benefícios econômicos e ambientais. Essas práticas reduzem o consumo de água, os custos operacionais, contribuindo para a conservação dos ecossistemas fluviais e costeiros. A adoção dessas tecnologias em edifícios educacionais pode servir de modelo para outras instituições, fortalecendo a resiliência hídrica e a sustentabilidade.
- A low power photovoltaic water pumping system based on a DC-DC step-up converter and standard frequency convertersPublication . Fey, Alice Nogueira; Leite, Vicente; Romaneli, Eduardo Felix RibeiroPhotovoltaic Water Pumping Systems (PVWPS) are a solution to supply water to populations living in arid and remote regions. One problem is that these systems are usually sold as closed kits and with solar energy dedicated equipment. This situation makes it difficult to replace damaged equipment for others that would be available on the market. Also, solar dedicated equipment are more expensive than the general-purpose ones. Another issue is the oversizing of the photovoltaic string in terms of power, when installing low power PVWPS that employ conventional AC water pumps. The oversizing occurs in order to achieve the voltage requirements of these pumps (rated with less than 1kW). In the interest of solving these problems, this work proposes a solution for a low power PVWPS. The proposed system employs a maximum of 4 photovoltaic modules; a DC-DC step-up converter; a standard frequency converter and an 1HP AC water pump. It was designed and tested a 750W DC-DC step-up converter with a static gain of 3.44 for composing the proposed solution. The whole set of the low power PVWPS was tested in a laboratory environment and showed a full day of operation. The present work was held in cooperation with the company VALLED.
- On-site power generation using biogas in sewage treatment plants: a techno-economic assessment of a brazilian uasb facilityPublication . Pérez, Nestor Proenza; Adrião Cabral, Edilson; Bimestre, Thiago Averaldo; Loures, Carla Almeida; Yepes Maya, Diego M.; Ribeiro, Luís FrölénSmall sewage treatment plants (STPs) in developing regions often flare the biogas produced in their upflow anaerobic sludge blanket (UASB) reactors, giving away a cost-effective energy source. This study tests whether on-site biogas-to-energy can pay for itself in approximately 2 years, even in plants treating less than 30 l s(-1). A small-scale STP in Angra dos Reis, Brazil (25 L/s), was studied, with an average biogas flow of 9.7 m(3)/h; electricity generation was modeled for an engine generator unit with an efficiency of 30%. The techno-economic results show that the actual system would generate 125 MWh/year at a levelized cost of 0.017-0.023 USD/kWh, covering 47% of the plant's electricity demand. At a discount rate of 8%, the net present value was + 9.3 k US$, and the simple payback period was 2 years for the initial investment. Additionally, extrapolating the results to account for future expansion of the sewage treatment plant based on the total population in the region served by the system reveals even more promising results, with a suggested payback period of 1 year and 1 month of operation, covering approximately 57% of electricity demand. Scaling this retrofit to the approximately 18,000 comparable UASB-based STPs worldwide at low capital cost could reduce electricity bills by approximately 40% and avoid similar to 450 tons of CO2-eq. per plant per year through methane capture and displacement of electricity from the grid. These results confirm that decentralized biogas power generation on a small scale is not only technically feasible, but also financially attractive and ecologically beneficial for operators of sewage and wastewater treatment plants and municipalities.
- On‐site power generation using biogas in sewage treatment plants: a techno‐economic assessment of a brazilian UASB facilityPublication . Pérez, Nestor; Cabral, Edilson; Bimestre, Thiago; Loures, Carla; Maya, Diego; Ribeiro, Luís FrölénSmall sewage treatment plants (STPs) in developing regions often flare the biogas produced in their upflow anaerobic sludge blanket (UASB) reactors, giving away a cost-effective energy source. This study tests whether on-site biogas-to-energy can pay for itself in approximately 2 years, even in plants treating less than 30 l s−1. A small-scale STP in Angra dos Reis, Brazil (25 L/s), was studied, with an average biogas flow of 9.7 m3/h; electricity generation was modeled for an engine generator unit with an efficiency of 30%. The techno-economic results show that the actual system would generate 125 MWh/year at a levelized cost of 0.017–0.023 USD/kWh, covering 47% of the plant’s electricity demand. At a discount rate of 8%, the net present value was + 9.3 k US$, and the simple payback period was 2 years for the initial investment. Additionally, extrapolating the results to account for future expansion of the sewage treatment plant based on the total population in the region served by the system reveals even more promising results, with a suggested payback period of 1 year and 1 month of operation, covering approximately 57% of electricity demand. Scaling this retrofit to the approximately 18,000 comparable UASB-based STPs worldwide at low capital cost could reduce electricity bills by approximately 40% and avoid ~ 450 tons of CO2-eq. per plant per year through methane capture and displacement of electricity from the grid. These results confirm that decentralized biogas power generation on a small scale is not only technically feasible, but also financially attractive and ecologically beneficial for operators of sewage and wastewater treatment plants and municipalities.
- 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.
- Rainwater harvesting with conventional or green roofs?Publication . Silva, Flora; Calheiros, Cristina; Albuquerque, António; Lopes, Jorge; Geraldes, Ana MariaThe present approach aims to evaluate the technical and financial feasibility of a rainwater harvesting system for an industrial building in Northeast Portugal, considering the existing conventional roof (scenario 1) and the adaptation of a green roof to the existing roof (scenario 2). In this evaluation, the impact of the two scenarios on the water savings of the building was considered. The expected water savings were 64.47% and 59.43% for scenarios 1 and 2, respectively. Therefore, the expected reduction in the annual water bill was €3867.07 + VAT (scenario 1) and €3564.63 + VAT (scenario 2). For scenario 1, considering a reservoir of 70 m3 for non-potable purposes, such as washing the floor of the building and use in industrial machinery, and an initial investment of 41,109.13 € + VAT, the single payback is 11.29 years. The single payback for Scenario 2 largely exceeded the lifetime of the green roof. However, financial incentives could be proposed to implement green roofs in this building typology, as they are considered interesting solutions to reduce the negative externalities of industrial settlements.
- Removal/recicling microcontaminants and plastic pollution in waters and soils through physical, chemical and/or biological processesPublication . Dominguez, Joaquin R.; Gomes, Helder T.; Augusto, Paulo A.; García, Juan; Hodaifa, Gassan; Álvarez-Torrellas, Silvia; Peres, José A.; Minhalma, Miguel; Charas, AnaThis special issue of the journal brings together research presented at three international environmental conferences held in Lisbon (2024). It highlights the field’s shift toward integrated and sustainable approaches, addresses global challenges (climate, water, pollution, energy), and includes studies on environmental remediation, circular economy, and new technologies. It also emphasizes the journal’s role in scientific dissemination.