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- Nexus água-nutrientes-energia: uma abordagem integrada no tratamento de efluentes suinícolasPublication . Oliveira, Margarida; Pena, L.; Fragoso, Rita; Duarte, ElizabethA preocupação com os impactes ambientais associados a explorações pecuárias de produção intensiva tem vindo a aumentar nos últimos anos. Em especial, a elevada concentração de azoto e fósforo dos efluentes suinícolas poderá induzir a poluição dos cursos de água, se a sua gestão não for adequada. Com a crescente procura por energias alternativas às fósseis, novas perspetivas têm sido aplicadas à gestão dos efluentes suinícolas, onde para além do tratamento e redução da carga contaminante dos efluentes, se dá importância à sua valorização. Neste trabalho, estudou-se a depuração dos efluentes suinícolas por Lemna minor e a valorização energética da biomassa produzida por co-digestão anaeróbia. Foram realizados ensaios experimentais comparativos do crescimento da Lemna minor em meio artificial sintético e em efluente suinícola simulando as condições da última lagoa de uma suinicultura. A eficiência de remoção de CQO nos ensaios de depuração foi de 60,0 ±1,0 %. A maior taxa de crescimento observada em efluente suinícola foi de 28,7 ± 2,3 g m-2 dia-1 e as taxas de absorção de nutrientes obtidas foram de 140 mg N m-2 dia-1 e de 3,5 mg P m-2 dia-1. A avaliação do potencial de valorização energética da biomassa foi considerado em ensaios de co-digestão anaeróbia, comparando os ensaios de digestão anaeróbia utilizando efluente suinícola como mono-substrato e a co-digestão, utilizando Lemna minor como co-substrato. Os resultados obtidos evidenciaram o aumento na taxa de produção de biogás e da produção específica de metano em 40% e 44%, respetivamente. Esta abordagem integrada baseada no nexus-água-nutrientes-energia revelou-se promissora para a gestão de efluentes suinícolas. Novos estudos deverão explorar os benefícios combinados e potenciais vantagens e desvantagens destas tecnologias em diferentes escalas.
- Potential of duckweed for swine wastewater nutrient removal and biomass valorisation through anaerobic co-digestionPublication . Pena, Luis; Oliveira, Margarida; Fragoso, Rita; Duarte, ElizabethOver the last decades, phytodepuration has been considered an efficient technology to treat wastewaters. The present study reports a bench scale depuration assay of swine wastewater using Lemna minor. The highest observed growth rate obtained in swine wastewater was 3.1 ± 0.3 gDW m−2 day−1 and the highest nitrogen and phosphorus uptake were 140 mg N m−2 day−1 and 3.47 mg P m−2 day−1, respectively. The chemical oxygen demand removal efficiency in the swine wastewater assay was 58.9 ± 2.0%. Furthermore, the biomass valorisation by anaerobic co-digestion with swine wastewater was assessed. Results showed a clear improvement in specific methane production rate (around 40%) when compared to mono-substrate anaerobic digestion. The highest methane specific production, 131.0 ± 0.8 mL CH4 g−1 chemical oxygen demand, was obtained with a mixture containing 100 g of duckweed per liter of pre-treated swine wastewater. The water-nutrients-energy nexus approach showed to be promising for swine waste management.
- Winery wastewater treatment : evaluation of the air micro-bubble bioreactor performancePublication . Oliveira, Margarida; Duarte, ElizabethThe wine sector has faced increasing pressure in order to fulfill the legal environmental requirements, maintaining a competitive position in a global market. The rising costs associated have stimulated the sector to seek sustainable management’s strategies, focussing on controlling the demand for water and improving its supply.Some EU Directives were implemented concerning water protection and management. These included in particular the Framework Directive in the field of water policy and environmental legislation about specific uses of water and discharges of substances.Several winery wastewater treatments are available, but the development of alternative technologies is essential to increase their efficiency and to decrease the investment and exploration costs.The main goals of the present paper are the comparison of different biological treatment systems, in particular fixed and suspended biomass, operating under aerobic conditions. Since the accurate design of the bioreactor is dependent on many operational parameters, aspects related to hydraulic retention time; oxygen mass transfer and contact time, energetic costs; sludge settling and production; response time during startup, flexibility and treated wastewater reuse, in crop irrigation, with the aim of closing the water cycle in the wine sector, will be addressed. A new treatment system will be presented as a case study, an air micro-bubble bioreactor (AMBB), that will highlight the advantages and constraints on its performance at bench-scale and full-scale, in order to fulfill the gaps associated with the implemented winery wastewater treatment systems. The data presented was collected during four years monitoring plan and used to develop a tool to support the selection of the best available technology. The present study will also contribute to the implementation of an integrated strategy for sustainable production in the wine sector, based on a modular and flexible technology that will facilitate compliance with environmental regulations and potential reuse for crop irrigation. This approach will contribute to the development of a bio-based economy in the wine sector that should be integrated in a Green Innovation Economy Cycle.
- Water and wastewater management for sustainable viticulture and oenology in South Portugal – a reviewPublication . Costa, Joaquim; Oliveira, Margarida; Egipto, R.; Cid, J. F.; Fragoso, Rita; Lopes, C. M.; Duarte, ElizabethAssessing sustainability of the wine industry requires improved characterization of its environmental impacts, namely in terms of water use. Therefore, quantification of water inputs and wastewater (WW) outputs is needed to highlight inefficiencies in wine production and related consequences for the environment. Water use and WW generation in irrigated viticulture and oenology remains insufficiently quantified for dry Mediterranean regions (e.g. South Portugal). This paper is focused on wine production under warm and dry climate conditions in the winegrowing region of Alentejo (South Portugal). This region experiences increasingly dry conditions, while the irrigated area keeps expanding, which puts exacerbates the pressure on existing local and regional water resources. Additionally, more erratic variation in climate conditions and the tendency for increasingly extreme climate events (e.g. heat waves) pose more challenges to Alentejo’s wine sector. We conclude that quantitative information on water use and management is not always easy to obtain or access, which hinders improved strategies and/or policies for water use at farm, winery and region-level. Up-to-date statistics and robust metrics can help to better characterize water use and WW flows for Alentejo’s wine region, while optimizing management in vineyards and wineries, in companies and region-wide. The paper is focused on a “Farm-Winery” scenario, which is the most common in South Portugal’s wine sector
- Integrated approach to winery waste: waste generation and data consolidationPublication . Oliveira, Margarida; Duarte, ElizabethThe winemaking process involves the generation of a significant amount of waste and wastewater. These residues should be addressed for recycling or treatment before being returned to environment. As each winery is unique in waste generation and disposal, plans for environmentally friendly waste management are not universal and should be tested for their effectiveness. In this study, a diagnostic was made during three years, in different wineries, throughout Portugal, in order to quantify and characterize the waste and the wastewater produced. The results showed that solid waste and wastewater are mainly produced during the harvest period, corresponding to 74% and 87%, respectively. One ton of processed grape approximately produce 0.13 t marc, 0.06 t lees, 0.03 t of stalks and 1.65 m3 of wastewater. No significant differences (P<0.05) were observed for grape marc, lees and wastewater ratios, between years or wineries. With respect to the stalk ratio, there was no effect of year but the winery significantly affected this ratio (P<0.05). During the study period the treated wastewater, since diluted, revealed suitable characteristics for irrigation representing an additional source of water. In this regard, the data acquisition and consolidation ensure the transfer of information and experience which constitute an essential step in a support decision tool design.
- Challenges for modern wine production in dry areas: dedicated indicators to preview wastewater flowsPublication . Oliveira, Margarida; Costa, J. M.; Fragoso, Rita; Duarte, ElizabethWine production is an important socio-economic activity in Mediterranean countries. This study is focused on wine production under warm and dry climate conditions in south Portugal, in two major wine-producing regions (Tejo and Alentejo), characterized by small to medium sized wineries. Vineyards have been expanding in this region of Portugal, where about 50–70% of the vineyards are irrigated, increasing regional water demand. The aim of this study is to propose an integrative approach for wine production, where a simple calculation model has been developed and validated to preview water consumption and wastewater production, as functions of winemaking periods and type of processed grapes. Results revealed a global ratio of 2.2 ± 0.45 and 2.1 ± 0.17 Lwater/Lwine. Concerning dedicated indicators, 60–75% of the wastewater was produced during Period I and the red wine production represented a 50–64% increase in water consumption. This tool will enable winemakers to calculate Global and Dedicated Indicators, based on their own parameters, which provide information on flow volumes and peak flows. In this context, it will be possible to identify improvements for wastewater treatment and management towards water reuse as a promising solution for the wine sector in the framework of the circular economy.
- Bioreator aeróbio de microbolhas: estudo de caso na indústria vinícolaPublication . Oliveira, Margarida; Duarte, ElizabethOs sistemas de tratamento aeróbio de águas residuais vinícolas são de uso comum, devido à sua eficiência e versatilidade mas, evidenciam um consumo de energia elevado, geram grande volume de lamas, têm custos de implantação elevados e não estão ainda totalmente otimizados. O presente estudo visa a conceção e otimização de um biorreator vertical aeróbio de microbolhas (AMBB), à escala piloto, destinado ao tratamento de águas residuais vinícolas. O desempenho do AMBB foi estudado e ajustado em diferentes condições operacionais (regime de alimentação, arejamento e carga orgânica), com base em variáveis de resposta, designadamente carência química de oxigénio (CQO), polifenóis e biomassa produzida, com vista à reutilização da água, diminuição da produção de lamas e do consumo energético e à recuperação de subprodutos vinícolas. Nos ensaios em descontínuo, a remoção de CQO foi de 98-99%, após 15 dias de tratamento, enquanto em regime contínuo essa remoção foi de 93-96%, para uma taxa de arejamento de 20 min h-1 e diferentes taxas de carga orgânica aplicadas. No período da segunda trasfega, a redução da taxa de arejamento (5 min h-1) não alterou significativamente a remoção de CQO, permitindo reduzir o consumo energético e os custos de funcionamento. Apesar da remoção de polifenóis ter sido menos eficiente, estes compostos foram recuperados por sedimentação e ultrafiltração. A biodegradabilidade das águas residuais produzidas em cada fase do processo de vinificação, incluindo um fluxo pouco estudado, decorrente da introdução no processo das melhores técnicas disponíveis, foi avaliada através de características físico-químicas, métodos respirométricos e parâmetros cinéticos, para prever o seu comportamento quando descarregadas no sistema de tratamento. No seu conjunto, os resultados revelaram que o AMBB é uma alternativa economicamente viável aos tratamentos convencionais.
- Water management toward regenerative wineriesPublication . Oliveira, Margarida; Saraiva, Artur; Lambri, M.; Rochard, J.; Fragoso, R.; Romanini, E.; Hipólito, P.; Ettore, C.; Duarte, ElizabethWine producers are now fully aware of the water-energy nexus, given the challenges created by climate change. By identifying potential environmental impacts of the wine industry, related to water and fossil energy use, wineries are taking action to improve their performance. This chapter reviews a set of technologies and strategies that can lead wineries to implement a regenerative approach, minimizing resources, recovering value from wastewater/waste, and replacing fossil energy with renewable sources. The approach is illustrated by presenting four case studies, located in three Mediterranean countries (France, Italy, and Portugal). The main conclusions are: (1) water and energy consumption ratios vary according to the wine type; (2) wastewater treatment systems tend to close the water cycle in countries facing severe water scarcity; and (3) the adoption of renewable energy in wineries is a reality today, but the adopted renewable energy depends on the region where it is located.