ESTiG - Artigos em Revistas Indexados à WoS/Scopus
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Percorrer ESTiG - Artigos em Revistas Indexados à WoS/Scopus por Objetivos de Desenvolvimento Sustentável (ODS) "06:Água Potável e Saneamento"
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- 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.
- Tracking urban impacto n the Fervença river via water quality indexPublication . Martins, Ramiro; Pietrobelli, JulianaWater quality is crucial for the survival of living organisms and their environment. The Water Quality Index (WQI) is commonly used to monitor and minimize pollution. This study utilized The WQI was used to evaluate the water quality of the Fervença River in Bragança, Portugal, from January to June 2022. Water samples were collected monthly at five locations along the river. The WQI, which is based on physical, chemical, and biological parameters, provides a comprehensive numerical assessment, ranging from 0 to 100. In general, points 1-4 exhibited a good WQI and showed similar results. However, at point 5, reduced WQI values were consistently observed in all sampling campaigns, indicating a likely connection with discharge from the nearby wastewater treatment plant. The winter season, which is typically characterized by higher rainfall in the region, experienced severe drought during the study period. Consequently, the influence of rainfall on the WQI parameters could not be evaluated as expected, particularly from January to March. Comparing the obtained results, it is evident that as the Fervença River flows through the city of Bragança, the water quality indices decrease in most campaigns, particularly after Point 5. This finding highlights the negative influence of cities on the river water quality. This study highlights the importance of assessing water quality. Points 1 to 4 demonstrated good water quality, whereas point 5 showed reduced quality, linked to the wastewater treatment plant. Drought and city influence affect river water quality, which is crucial for the survival of living organisms and their environments.