A carregar...
6 resultados
Resultados da pesquisa
A mostrar 1 - 6 de 6
- Pegada de carbono de sistemas de tratamento de águas residuais urbanasPublication . Serafini, Laís Fabiana; Feliciano, Manuel; Bortoli, Marcelo; Costa, CláudioAs águas residuais urbanas são resultado do uso da água para fins domésticos e industriais, que, se não forem tratadas, se tornam um problema ambiental, contaminando solos e recursos hídricos. Para serem devolvidas ao ambiente, estas águas precisam passar por uma série de etapas de tratamento. As Estações de Tratamento de Águas Residuais (ETARs) são responsáveis pela diminuição do potencial poluidor dessas águas residuais e, desta forma, são vistas como infraestruturas que beneficiam o ambiente. Todavia, durante o tratamento, os processos envolvidos transformam os constituintes da água residual em quantidades não negligenciáveis de Gases de Efeito Estufa (GEE) para atmosfera, que acabam por contribuir para as alterações climáticas. Os principais GEE associados às emissões das ETARs são o CO2, CH4 e N2O, os quais são igualmente emitidos em maior quantidade pela atividade antrópica. Este estudo teve como objetivo principal avaliar a pegada de carbono associada à fase de exploração de uma (ETAR), localizada no norte de Portugal, adotando uma abordagem metodológica de Análise do Ciclo de Vida (ACV). Além disso, com o intuito de propor um conjunto de medidas conducentes à redução das emissões de GEE da ETAR em estudo, procedeu-se também à avaliação de um conjunto de cenários alternativos. Após a definição dos objetivos e do âmbito de estudo, preparou-se uma ficha de inventário de dados e de informação a obter junto dos responsáveis da ETAR, bem como de um conjunto de outras fontes de informação disponíveis. O inventário foi organizado com base na metodologia adotada pelo Painel Intergovernamental sobre as Alterações Climáticas, a qual separa a contribuição das emissões associadas a 3 âmbitos distintos – emissões diretas, indiretas internas e indiretas externas para a situação atual e para um conjunto de cenários alternativos relacionados com alterações do processo de tratamento, implementação de energias renováveis e gestão das lamas produzidas na ETAR. A pegada de carbono foi depois estimada para todas as situações com recurso a uma ferramenta em Excel, adaptada da aplicação informática “Cálculo da pegada de carbono das estações de tratamento de águas residuais suecas” (SVU 12-120). A pegada de carbono obtida foi de 1,3 kg CO2e/m3 de água residual tratada. Os resultados mostram que os processos biológicos de tratamento da fase líquida da ETAR constituem a fonte direta mais relevante de GEE, seguindo-se fontes indiretas relacionadas com o uso de energia e com a gestão de lamas. A avaliação dos cenários estudados permitiu obter reduções da pegada até 26%, motivadas sobretudo pela implementação de energias renováveis e pela alteração do tratamento das águas residuais.
- The Composting of Water Hyacinth: A Life Cycle Assessment PerspectivePublication . Serafini, Laís Fabiana; Arrobas, Margarida; Rodrigues, M.A.; Feliciano, Manuel; Miguens, Filomena; Oliveira, Verónica; Santos, Daniela; Díaz de Tuesta, Jose Luis; Gonçalves, ArturWater hyacinth is an invasive species that causes eutrophication in lentic waters. While mechanical removal is effective,it generates hazardous waste with biological contamination risk. Composting is a safe waste treatment option, inhibiting seeds and yielding agriculturally suitable compost. Life cycle assessment evaluated the environmental impacts of six composting piles using eight different by-products (potato peel, cattle manure, wood chip, rice straw, potato leftovers, olive pomace and biochar), all formulations containing water hyacinth. The worst environmental performances were the M2 pile (water hyacinth + olive pomace + cattle manure + potato leftovers) which achieved the highest AP (47.33 kg SO2 eq.) and EP (10.56 kg PO4³− eq.), while M3 (water hyacinth + olive pomace + rice straw + potato leftovers) had the highest GWP (816.51 kg CO2 eq.) and OLD (2.99E-11 kg R11 eq.). The biological composting process contributed the most to the overall increase in the impact categories for all piles due to air emissions (CH4 and N2O). M3 and M5 (water hyacinth + wood chip) had the worst performance in fossil fuel consumption due to distances travelled from by-products and energy use in the maintenance of composting piles. Concerning packaging, Big Bags with polypropylene had a greater impact than polyethylene bags (50 kg capacity). Evaluating the potential avoidance of mineral fertilisers, M3 compost showed potential for reducing TSP fertiliser production by 46%. Overall, M4, which incorporated a mixture of water hyacinth, olive pomace, wood chips and biochar, was the most favourable option from an environmental point of view.
- Systematic review and meta-analysis on the use of LCA to assess the environmental impacts of the composting processPublication . Serafini, Laís Fabiana; Feliciano, Manuel; Rodrigues, M.A.; Gonçalves, ArturFollowing the industrial revolution, major economic and populational growth took place, and, therefore, solid waste generation increased exponentially. Nowadays, waste management still generates major impacts because the current wide offer of waste management strategies includes many solutions that produce suboptimal results, such as landfill or waste incineration. From a circular economy perspective, composting is a potentially sustainable option to treat the organic fraction of solid waste and has the advantage of recycling many organic compounds that can be reintroduced into the natural processes. This study aimed to provide a meta-analysis using the Life Cycle Assessment (LCA) method to evaluate the impacts of composting by performing a systematic literature review of the diversity of approaches and assessing environmental impacts. The results of the impact assessment were highly dependent on the choices made over the system boundary and the functional units. The most cited environmental impacts were GlobalWarming Potential, Acidification Potential, Eutrophication Potential, Photochemical Oxidation Potential, and Ozone Layer Depletion, as gaseous emissions from the transport and decomposition represent the main contributors to these categories. Using a smaller dataset and evaluating the use of the CML method and the most cited impacts categories, it was found that In-vessel Composting and Home Composting were considered the best environmental options among the studied composting methods. Composting environmental impacts were also highly related to the use of non-renewable energy sources, which puts composting at a disadvantage when compared with the use of anaerobic digestion. Such results emphasize the benefits of using these waste management technologies as complementary instead of substitutes.
- The Composting of Water Hyacinth: A Life Cycle Assessment PerspectivePublication . Serafini, Lais Fabiana; Arrobas, Margarida; Rodrigues, Manuel Ângelo; Feliciano, Manuel; Miguens, Filomena; Oliveira, Verónica; Santos, Daniela; Díaz de Tuesta, Jose Luis; Gonçalves, ArturWater hyacinth is an invasive species that causes eutrophication in lentic waters. While mechanical removal is effective, it generates hazardous waste with biological contamination risk. Composting is a safe waste treatment option, inhibiting seeds and yielding agriculturally suitable compost. Life cycle assessment evaluated the environmental impacts of six composting piles using eight different by-products (potato peel, cattle manure, wood chip, rice straw, potato leftovers, olive pomace and biochar), all formulations containing water hyacinth. The worst environmental performances were the M2 pile (water hyacinth + olive pomace + cattle manure + potato leftovers) which achieved the highest AP (47.33 kg SO2 eq.) and EP (10.56 kg PO4³− eq.), while M3 (water hyacinth + olive pomace + rice straw + potato leftovers) had the highest GWP (816.51 kg CO2 eq.) and OLD (2.99E-11 kg R11 eq.). The biological composting process contributed the most to the overall increase in the impact categories for all piles due to air emissions (CH4 and N2O). M3 and M5 (water hyacinth + wood chip) had the worst performance in fossil fuel consumption due to distances travelled from by-products and energy use in the maintenance of composting piles. Concerning packaging, Big Bags with polypropylene had a greater impact than polyethylene bags (50 kg capacity). Evaluating the potential avoidance of mineral fertilisers, M3 compost showed potential for reducing TSP fertiliser production by 46%. Overall, M4, which incorporated a mixture of water hyacinth, olive pomace, wood chips and biochar, was the most favourable option from an environmental point of view.
- Life cycle approach as a tool for assessing municipal biowaste treatment units: a systematic reviewPublication . Serafini, Lais Fabiana; Praça, Paulo; González-Andrés, Fernando; Gonçalves, ArturBiowaste is an increasingly relevant environmental issue worldwide, causing significant environmental, economic and social impacts. Effective strategies are crucial to mitigate impacts, maximising biowaste’s valorisation. This article presents a systematic literature review on using life cycle assessment (LCA) to evaluate municipal biowaste treatment facilities. The primary objective was to analyse how LCA is applied to assess the environmental efficiency of mechanical and biological treatment involving composting and anaerobic digestion (AD)-based systems. The article addressed the methodological heterogeneity across previous LCA studies, identifying critical gaps and challenges regarding standardisation and result comparability. It underscores the importance of accurately considering environmental indicators and emission factors, as these significantly affect overall LCA outcomes. Results show that most publications focus on Europe and Asia, highlighting a research gap in regions like Africa. The organic fraction municipal solid waste is the predominant feedstock, and 1 tonne of biowaste was the frequently used functional unit, reflecting the upstream impacts of waste. The most recurrent system boundary was the cradle-to-grave, offering a comprehensive analysis as it covers all stages of biowaste treatment from collection to disposal. The studies highlight the environmental benefits of AD-based systems through energy production compensations, particularly in reducing global warming potential, compared with other treatment operations such as landfills. While replacing mineral fertilisers with digestate and compost is very well discussed, it raises concerns about heavy metal content and nutrient availability. Therefore, selective collection of organic waste is crucial to improve compost quality and AD efficiency, though it increases transportation costs.
- Enhancing team engagement and notoriety for youth: strategies for gdbPublication . Rodrigues, Pedro; Afonso, Patrício; Ali, Asfand; Rodrigues, Carolina; Ramos, Frederico; Serafini, Lais Fabiana; Afonso, Carlos; Pereira, Fernando A.The proposed action plan of the co-creation challenge seeks to increase the engagement and visibility of a sports team, with particular emphasis on attracting young people and diverse audiences. The central issue addressed is the lack of engagement, which has resulted in declining relevance, motivation, and revenue streams for the team. The proposed solution adopts a multi-faceted approach comprising a digital marketing plan, the organisation of an open day, and the hosting of e-sports tournaments. These strategies are intended to bridge the gap between younger audiences and the team, create new revenue streams, engage e-sports players, and promote diversification into other sports. This initiative represents an important step towards revitalising the team’s presence and appeal within a rapidly evolving sports and entertainment landscape.