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CHANGE - Global Change and Sustainability Institute
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Partial replacement of concentrate in the lactating ewe's diet with silages of agro-industrial by-products
Publication . Jerónimo, Eliana; Cachucho, Liliana; Alves, Helder; Guerreiro, Olinda; Paulos, Kátia; Costa, Cláudia; Costa, João; Gomes, Sandra; Alvarenga, Nuno; Alves, Susana P.; Bessa, Rui J. B.; Santos-Silva, José; Dentinho, Maria Teresa P.; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; Elsevier BV
The purpose of this experiment was to evaluate the effect of partial replacement of concentrate feed with mixed ingredient silages (MIS) produced with agro-industrial by-products in the diets of lactating ewes on the body weight of ewes, growth performance of suckling lambs, composition and fatty acid (FA) profile of milk, and serum metabolites of the ewe. After lambing, 54 lactating ewes and their lambs were distributed to one of the following experimental diets (18 ewes/diet): C – concentrate diet; SPBG – concentrate and silage containing 200 g/kg sweet potato, 500 g/kg brewers grains and 300 g/kg alfalfa hay; and AHBG – concentrate and silage containing 200 g/kg almond hulls, 600 g/kg brewers grains and 200 g/kg alfalfa hay. Hay was provided ad libitum in all diets. In both silage diets (SPBG and AHBG) the concentrate and silage constitute 33.3 and 66.6 % DM of the diet, respectively. Every day, the ewes received the same amount of the diet, which was completely consumed. Lambs were weighed at birth and weekly during the 8 weeks of trial. In the last 4 weeks of the trial, individual milk samples were collected weekly and then pooled per each ewe for chemical analysis. At the end of the trial, a blood sample was collected from the ewes to analyse serum metabolites. SPBG and AHBG silage showed pH values of 4.00 and 4.29, respectively. Total N as NH3-N and as soluble-N varied from 3.23 to 5.23 and from 348 to 354 g/kg total N, respectively. The animals well accepted the silages. Partial replacement of concentrate with silage of agro-industrial by-products in lactating ewe diets did not affect the growth performance of suckling lambs and the composition of milk. Both silage dietary treatments changed the milk FA composition, reducing the short-chain FA (6:0–14:0), branched-chain FA, and 18:1 trans-10, and increasing the saturated FA 16:0, 18:0, 20:0, 22:0, 23:0 and 24:0 and 18:1 trans-11. Regarding serum metabolites, silage diets increased the urea concentration and decreased the β-hydroxybutyrate concentration. Results showed that ensiling is a good approach to preserving sweet potato, almond hulls, and brewers grains, producing a good quality feed that can be introduced to diets of lactating ewes without compromising animal performance.
Treated wastewater reuse for irrigation
Publication . Areosa, Inês; Martins, Tiago A. E.; Lourinho, Rita; Batista, Marcos; Brito, António G.; Amaral, Leonor; DCEA - Departamento de Ciências e Engenharia do Ambiente; CENSE - Centro de Investigação em Ambiente e Sustentabilidade; Elsevier
In an increasing water scarcity and climate-vulnerable global context, treated wastewater represents a vital alternative water source, thereby enhancing resource sustainability. Despite its potential, only roughly 2.5 % of the treated wastewater is reused in the European Union, with Portugal's reuse rate being only 1.2 % in 2022. Considering this framework, this study evaluates the feasibility of increasing wastewater reuse in Portugal by focusing on the Tagus River and Ribeiras do Oeste Basins. The regional assessment identified eight key wastewater treatment plants (WWTP) with significant potential for irrigation reuse in the agriculture and tourism sectors. Analysing costs, quality requirements, and technological options, this study considered five treatment lines, incorporating filtration and disinfection methods. The findings indicate that reclaimed water costs may range from 0.02€/m3 to 0.83€/m3, being competitive with other water sources and significantly lower than desalination processes (up to 1.66€/m3). Distribution investments and energy consumption are primary cost drivers, suggesting a relocation of WWTP closer to end-users as a cost-saving strategy. The proposed reuse projects could quadruple regional reuse rates and double the national rate, mitigating water needs for over 2000 ha of agricultural land and golf courses. This study underscores the importance of treated wastewater reuse in addressing water scarcity, advocating for WWTP decentralisation, strategic investments and policy interventions to achieve cost-effective goals. The methodologies and insights presented offer valuable guidance for other regions facing similar challenges, promoting a paradigm shift towards circular water resource management.
Xylitol Production by Debaryomyces hansenii in Extracted Olive Pomace Dilute-Acid Hydrolysate
Publication . Morais, Ana Rita C.; Duarte, Luís C.; Lourenço, Pedro; Torrado, Ivone; Brás, Teresa; Neves, Luísa A.; Carvalheiro, Florbela; LAQV@REQUIMTE; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
The extracted olive pomace (EOP) is an industrial lignocellulosic by-product of olive pomace oil extraction, currently mainly used for energy production through combustion. In this work, the hemicellulosic fraction of EOP was selectively hydrolyzed by diluted acid hydrolysis to obtain pentose-rich hydrolysates that can potentially be upgraded by Debaryomyces hansenii, targeting xylitol production. The monosaccharides and degradation by-products released along the pre-treatment were quantified and several detoxification methods for the removal of potentially toxic compounds were evaluated, including pH adjustment to 5.5, the use of anion-exchange resins, adsorption into activated charcoal, concentration by evaporation, and membrane techniques, i.e., nanofiltration. The latter approach was shown to be the best method allowing the full removal of furfural, 41% of 5-hydroxymethylfurfural, 54% of acetic acid, and 67% of the phenolic compounds present in the hydrolysate. The effects of the supplementation of both non-detoxified and detoxified hydrolysates were also assessed. The non-detoxified hydrolysate, under aerobic conditions, supported the yeast growth and xylitol production at low levels. Supplementation with the low-cost corn steep liquor of the nanofiltration detoxified hydrolysate showed a higher xylitol yield (0.57 g/g) compared to the non-detoxified hydrolysate. The highest xylitol productivity was found in hydrolysate detoxified with anionic resins (0.30 g/L·h), which was 80% higher than in the non-detoxified culture medium. Overall, the results showed that EOP dilute acid hydrolysates can efficiently be used for xylitol production by D. hansenii if detoxification, and supplementation, even with low-cost supplements, are performed.
Leveraging local environmental management in the scope of an administrative decentralization process
Publication . Arroyave, Lina Ortiz; Lopes, Rita; Santos, Rui; CENSE - Centro de Investigação em Ambiente e Sustentabilidade; Academic Press | Elsevier
Administrative decentralization has been widely promoted as a pathway to more responsive and context-sensitive governance; however, its implications for local environmental management remain underexplored. This study examines how to leverage local environmental management in the context of administrative decentralization in Portugal, focusing on coastal municipalities. Our findings reveal that despite formal administrative decentralization reforms, central government retains strong control through uniform competence structures that disregard regional specificities, limiting municipalities' capacity for local environmental management. Municipalities exhibit a preference for maintenance and operational tasks over strategic planning roles, reflecting constrained autonomy and resource limitations. Drawing on these insights, we propose a conceptual framework for strengthening local environmental management under administrative decentralization, highlighting four critical factors: (i) institutional capacity (political, human, and technical resources); (ii) financial and political autonomy; (iii) multi-level and cross-sectoral collaboration; and (iv) local political willingness to act proactively. This framework offers practical guidance for designing context-sensitive, participatory approaches to environmental governance, contributing to both theoretical debates and policy implementation. Our study underscores the importance of capacity-building and sustained stakeholder engagement to ensure decentralization reforms translate into effective local environmental outcomes.
Application of General Unified Threshold Models to Predict Time-Varying Survival of Mayfly Nymphs Exposed to Three Neonicotinoids
Publication . Lourenço, Vanessa S. C.; Figueiredo, Neusa L.; Daam, Michiel A.; CENSE - Centro de Investigação em Ambiente e Sustentabilidade; MARE - Centro de Ciências do Mar e do Ambiente; MDPI - Multidisciplinary Digital Publishing Institute
Pesticide exposure patterns tested in laboratory bioassays often do not match real-world pesticide exposure profiles in edge-of-field waterbodies. Toxicokinetic–toxicodynamic (TKTD) models are therefore increasingly used, as they allow for predictions of the toxic effects under actual time-variable field exposures. The TKTD models from the General Unified Threshold models of Survival (GUTS), for example, are considered ready for use by regulators for calculating the survival rates for any time-variable exposure profile. However, questions remain regarding their predictive power for compounds showing increased toxicity over time, such as neonicotinoid insecticides. The aim of the present study was therefore to compare the GUTS-predicted 28 d toxicity values of three neonicotinoids (imidacloprid, clothianidin, and thiamethoxam) for the common New Zealand mayfly genus Deleatidium spp. with those observed in a previously published study. Overall, the GUTS modeling results underestimated the toxicity values derived experimentally. From the three neonicotinoids, clothianidin showed the best fit between the estimated and observed 28 d LC50 (median-lethal-concentration) values. Shortcomings of the modeling exercise, future research needs, and implications for the application of GUTS models in regulatory risk assessment are discussed.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
LA/P/0121/2020