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- Local waste agroforestry managment - biomass to energy analysis with LCAPublication . Brás, Isabel; Ferreira Silva, Maria Elisabete; Ferreira, José; Raimondo, Roberta; Saetta, Rafaella; Fabricino, MassimilainoTo enable the protection of forests against rural fires are foreseen a set of measures for plan-ning and intervention, reduction their risk and impacts. Forest residues collecting centers are being created in Portugal, to reduce undesired thermal charge in nature and for biomass further valorization. Keeping this in mind, one of the strategies is the energy recovery from these residues in bi-omass power plants that were built in strategic locations. The biomass is mostly natural residu-al forest, agricultural and garden wood and green materials The present work aims to study its environmental impact. The Life Cycle Assessment methodology, using SimaPro 9.3.0.3 PhD software, was applied to identify the burden of this process and the environmental categories most relevantly affect-ed. Data achieved showed the importance of the valorization of residual biomass for energy production, reduction the impact categories of abiotic depletion due to fossil fuels, global warming, human toxicity and eutrophication.
- Study of a solar energy drying system—Energy savings and effect in dried food qualityPublication . Pereira, Carlos; Tavares, A.P.; Cardão, P.; Castro, A.; Ferreira Silva, Maria Elisabete; Ferreira, D.W.; Lopes, S.; Brás, I.It is estimated that in Portugal per year, 132 kg/person of food is wasted due to imperfections in weight, shape and due to their perishability, resulting in foods that cannot be marketed. Solar drying can be used to extend food life. However, it usually does not meet the current productivity and quality requirements of the dried product. Solar energy is renewable, very available in Portugal, which can make an important contribution to reducing the specific energy consumption and carbon footprint intensity associated with drying. This work aims to optimize the drying process using a solar dryer with electric support. The conditions of temperature and humidity in the dryer and their influence on the physical and chemical properties of blueberries and raspberries were studied, namely the ash, protein, fat, sugars, total phenolic compounds content and antioxidant capacity. It was concluded that the blueberries and raspberries, after drying underwent slight changes in some chemical parameters, namely the reduction of fats and phenolic compounds. The results of the drying tests showed a strong dependence on atmospheric conditions. Under the most favorable conditions, it was possible to record reductions in electricity consumption of 35%.
- Forest waste composting—operational management, environmental impacts, and applicationPublication . Ferreira Silva, Maria Elisabete; Saetta, Raffaella; Raimondo, Roberta; Costa, José Manuel; Ferreira, José; Brás, IsabelIn Portugal, the number of fres and the size of burnt areas are rising dramatically every year, increasing with improper management of agroforestry wastes (AFRs). This work aims to study the composting of these wastes with minimal operational costs and understand the environmental impact and the compost application on burnt soil. Thus, a study of life cycle assessment (LCA) was carried out based on windrow composting processes, considering the avoided environmental impacts associated with the end-product quality and its application as an organic amendment. Three composting piles were made with AFRs from the Residual Biomass Collection Centre (RBCC) in Bodiosa (Portugal). Sewage sludges (SS) from an urban wastewater treatment plant were used as conditioning agent. One pile with AFRs (MC) and another with AFRs and SS (MCS) were managed according to good composting practices. Another pile with the AFRs was developed without management (NMC), thus with a minimal operational cost. Periodically, it was measured several physical and chemical parameters according to standard methodologies. Eleven environmental impacts of compost production, MC and MCS, were analyzed by a LCA tool, and their efect on the growth of Pinus pinea was evaluated, using peat as reference. Composting evolution was expected for both piles. Final composts, MC and MCS, were similar, complying with organic amendment quality parameters. Compost NMC, with no operational management, showed the highest germination index. Piles MC and MCS showed similar environmental impacts, contributing to a negative impact on global warming, acidifcation, and eutrophication. Greater growth was obtained with application of MCS, followed by MC, and fnally, peat. Composting is a sustainable way to valorize AFRs wastes, producing compost that could restore burnt soils and promote plant growth and circular economy.
- Influence of Different Agro-Food Waste on Ammonia and Greenhouse Gas Emissions during CompostingPublication . Pereira, José; Costa, Telma; Figueiredo, Vítor; Marques, Francisco; Perdigão, Adelaide; Brás, Isabel; Ferreira Silva, Maria Elisabete; Ferreira Wessel, DulcineiaComposting is one of the best organic waste management techniques, with zero waste; however, it generates environmental impacts. The objective of this study was to evaluate the emission of NH3, N2O, CO2, and CH4 from the composting of olive, elderberry, and grape agro-food waste. The experiment was carried out using reactors receiving straw as control and three treatments receiving mixtures of straw and olive, elderberry, or grape wastes. The gas emissions were measured for 150 days, and the composition of the mixtures and composts was determined. The results showed NH3 and CH4 emissions were reduced by 48% and 29% by the Olive and Elderberry treatments, while only NH3 loss was reduced by 24% by the Grape treatment. Nitrous oxide, CO2, and GWP emissions were reduced by 46%, 32%, and 34% by the Olive treatment, while these losses were not reduced by the Elderberry or Grape treatments. It can be concluded olive waste can effectively reduce NH3 and GWP, while elderberry and grape wastes are also effective in reducing NH3, but not GWP. Thus, the addition of agro-food waste appears to be a promising mitigation strategy to reduce gaseous losses from the composting process.
- Carbon Footprint of Tourism Sector in Portugal Calculator DevelopmentPublication . Fernandes, Marco; Neves, Pedro; Araújo, Patrícia; Brás, Isabel; Ferreira Silva, Maria ElisabeteA carbon footprint (CF) calculator was developed to apply to a Portuguese touristic accommodation to contribute to a sustainable touristic activity. Although some calculators are available online, they are related to the country reality or use outdated emission factors. A calculator based on national emission factors is important. The calculator was developed in Microsoft Excel (version 365) and is based on the CO2e emissions resulting from electricity, water, fuels and food use, laundry and waste production. The calculator development involved: study the accommodation emission sources, selection the environmental indicators, determination of the emission factors and development of the CF formulas. Total CF calculation was made considering the partial CF per component, a monthly and annual comparison of each indicator’s emissions contribution using graphs. The emissions amount per overnight stay, per room, per area, were also assessed and these values were transformed into global hectare (gha). Avoided emissions calculation gives the information about the efforts in CF reduction, and two indicators were considered: electricity production from renewable energy sources and the amount of separated waste for recycling. It was considered reforestation measures to achieve carbon neutrality. This calculator incorporates four components not often used: water, laundry, waste, food, and avoided emissions.
- Valorisation of Forest and Agriculture Residual Biomass—The Application of Life Cycle Assessment to Analyse Composting, Mulching, and Energetic Valorisation StrategiesPublication . Brás, Isabel; Ferreira Silva, Maria Elisabete; Raimondo, Roberta; Saetta, Raffaella; Mignano, Vincenzo; Fabbricino, Massimiliano; Ferreira, JoséThe treatment of agricultural and forest residues (AFRs) has become an important issue nowadays, both to avoid improper management and for their enhancement. In the study area of Viseu (Portugal), the AFRs are taken to a Residual Biomass Collection Centre. These are valorised in a Biomass Power Plant to produce electricity. Two further processes could be implemented to valorise this biomass: mulching and composting. This study aims to understand the best strategy to enhance this type of biomass residual considering their environmental performance. The Life Cycle Assessment (LCA) was applied considering a cradle-to-grave approach. Different processes of all the technologies were analysed, and the data collected enabled a comparison of 11 environmental impact categories. The results show that composting is the best alternative, except for global warming and ozone layer depletion, and energy valorisation has the greatest impact on five of the considered categories. In the three processes, impacts are mainly associated with the production and shredding phases of the residual biomass, rather than the transportation stages, due to the short distances covered. In all cases, the value of the final product generates market consequences in terms of electricity and fertiliser production. In line with the aim of the study, its outcomes may provide scientific support to local decision makers in defining best practices in the management of the AFRs.
- Avaliação de impacte ambiental da gestão de resíduos da produção de uma bancada com base na abordagem de ACVPublication . Silva, Luiza; Ferreira Silva, Maria Elisabete; Brás, Isabel; Domingos, Idalina; Ferreira Wessel, Dulcineia; Ferreira, JoséIntroduction: Consumerism has led to an increase in environmental problems, and for this reason, sustainable solutions must be the priority when designing new products or services. Life Cycle Assessment (LCA) is one of the most important analytical tools available for choosing the best decision when it comes to sustainability. Objective: The focus of this study was to apply an LCA to the management of wastes from a kitchen/bathroom countertop production. The waste management scenarios studied were landfill (current practice) and waste recycling. The panel consists of a ceramic layer on a lamellar panel substrate, formed by glassliner and PVC, which is intended to be resistant to water, scratches and impacts. The residues generated from the panel production are glassliner and PVC plastics and ceramics. Methods: The LCA methodology was followed and the EPD 2018 method available in the SimaPro software was chosen to quantify the environmental impacts of waste management. The environmental impact categories studied were eutrophication, global warming, photochemical oxidation, ozone layer depletion, abiotic depletion and acidification. Results: The results showed that the two plastic wastes are the main contributors to acidification, eutrophication and global warming. However, for photochemical oxidation and water scarcity, the ceramic component residue is the main contributor. Comparing the two scenarios, waste recycling reduces the impacts in all environmental impact categories, in comparison with landfill. Conclusion: Recycling the residues from the production of panels brings improvements in environmental impacts in all categories analyzed.
- Avaliação do efeito da recirculação de lixiviados num aterro sanitário.Publication . Brás, Isabel; Ferreira, Bruna Sofia; Ferreira Silva, Maria ElisabeteIntrodução: O aterro sanitário é uma técnica que aplica princípios de engenharia para confinar os resíduos numa menor área possível, reduzindo o seu volume. Deste tratamento resultam nomeadamente a produção de lixiviados, pelo que se impõe o estudo da sua recirculação.Objetivos: Fornecer uma perspetiva da prática do efeito da recirculação de lixiviados e de questões técnicas que o diferenciam dos aterros convencionais, tendo por base o aterro sanitário de Bigorne.Métodos: Efetuou-se o levantamento de diversos parâmetros físicos e químicos durante um período de 10 anos exploração do aterro, seguindo-se o respectivo tratamento estatístico.Resultados: A análise dos dados mostrou que a produção de lixiviados diminui com o início da recirculação de lixiviados, assim como a condutividade, após um aumento gradual, a carência bioquímica de O2 (CBO5) e carência química de O2 (CQO). Por sua vez, a concentração de azoto amoniacal tende a permanecer elevada e o pH aumenta para valores com caracter básico. As concentrações dos elementos minerais apresentaram um perfil variável. O chumbo e manganês tendem a diminuir, enquanto as concentrações dos elementos crómio, sódio e potássio tendem a aumentar. Quanto aos restantes elementos minerais (zinco, cobre, ferro, níquel, magnésio e cálcio), verifica-se que as suas concentrações tendem a se manter constantes. A maioria das correlações efetuadas entre a idade do aterro, o caudal recirculado e os elementos minerais não evidenciou correlações significativas. Salienta-se apenas a correlação significativa positiva entre o caudal recirculado com o crómio e potássio, evidenciando o efeito do caudal no aumento da concentração destes elementos minerais no interior do aterro.Conclusões: Estudar os mecanismos que controlam o comportamento de aterros com recirculação de lixiviados, permite o desenvolvimento de ferramentas de gestão adequadas às especificidades dos aterros.
- Selective collection of bio-waste in a non-intensive urban region – Producers’ characterizationPublication . Brás, Isabel; Maia, S.; Simões, Luís; Rabaça, Teresa; Ferreira Silva, Maria ElisabeteThe European circular economy targets and waste policies have gradually focused on bio-waste, which is considered one of several key waste streams and is urgently needed to develop strategies for their selective collection. In non-intensive urban regions, a selective collection is a challenge due to the dispersion of bio-waste producers. This work intended to characterize the bio-waste producers, in Planalto Beirão region (Portugal) and define strategies for their management. Planalto Beirão is a non-intensive urban region in the center of Portugal composed of 19 municipalities. The methodology involved collecting data from non-domestic bio-waste producers in Portuguese databases. The data of non-domestic producers were divided into 4 categories: HORECA sector (hotels, restaurants and coffee shops), Food commerce (wholesale and retail sale), Tea houses and Social services (education and activities in social support with and without accommodation). The analyzed data from the 4 categories of non-domestic bio-waste producers indicated that hotels, restaurants and coffee shops represented 46% of producers, followed by Food commerce, Social services and Tea houses with 33%, 17% and 4%, respectively. Viseu was determined as the municipality with the highest potential to implement a successful selective collection of bio-waste. In the Planalto Beirão region, the selective collection from non-domestic bio-waste producers must be done door-to-door, in higher-density areas. In rural areas, valorization should be introduced locally by the producers or the community.
- Comparative Life Cycle Assessment of Conventional Concrete to Ash ConcretePublication . Ferreira, José; Ferreira Silva, Maria Elisabete; Domingos, Idalina; Silva, Luiza; Brás, IsabelIn the present work, the environmental impacts of the concrete made with woody fly ash that presented compressive strength like the conventional concrete were evaluated and compared using the Life Cycle Assessment methodology. The impact assessment method used was the “CML-IA baseline” implemented in SimaPro software. The results showed that concrete with fly ash had a lower impact than conventional concrete in all the impact categories under study and may be classified as an eco-material (eco-concrete) considering that the environmental issues that are minimized are waste reduction, reduce of landfill problems and resource saving by the utilization of recycled materials.