Modified Block Newton method for the lambda modes problem

[EN] To study the behaviour of nuclear power reactors it is necessary to solve the time dependent neutron diffusion equation using either a rectangular mesh for PWR and BWR reactors or a hexagonal mesh for VVER reactors. This problem can be solved by means of a modal method, which uses a set of dominant modes to expand the neutron flux. For the transient calculations using the modal method with a moderate number of modes, these modes must be updated each time step to maintain the accuracy of the solution. The updating modes process is also interesting to study perturbed configurations of a reactor. A Modified Block Newton method is studied to update the modes. The performance of the Newton method has been tested for a steady state perturbation analysis of two 2D hexagonal reactors, a perturbed configuration of the IAEA PWR 3D reactor and two configurations associated with a boron dilution transient in a BWR reactor.This work has been partially supported by the Spanish Ministerio de Educación y Ciencia under projects ENE2008-02669 and MTM2007-64477-AR07, the Generalitat Valenciana under project ACOMP/2009/058, and the Universidad Politécnica de Valencia under project PAID-05-09-4285.González Pintor, S.; Ginestar Peiro, D.; Verdú Martín, GJ. (2013). Modified Block Newton method for the lambda modes problem. Nuclear Engineering and Design. 259:230-239. https://doi.org/10.1016/j.nucengdes.2011.06.045S23023925

Environmental assessment of different integrated biorefinery scenarios using walnut shells as a source for lignin production

Nowadays, the waste or loss of food produced along the supply chain is equivalent to approximately 33% of the total (FAO, 2013). However, the food sector can also contribute to solving the environmental problems it generates. The valorisation of food waste, with the aim of obtaining value-added compounds, represents a paradigm challenge within the framework of sustainable development. One of the products of high added value of greatest interest to the scientific community is lignin, due to its use as a source for obtaining chemical products. These lignin-based compounds must be competitive with petroleum derivatives from an economic and environmental aspect (Fernández-Rodríguez et al., 2021). In recent years, soda and organosolv processes have been placed at the centre of the biomass fractionation process spectrum. These processes make it possible to solubilise the lignin without altering its initial structure to any great extent (Fernández-Rodríguez et al., 2021). In the walnut processing industry, large quantities of shells are produced as by-products (approximately 400g per kilo of processed walnuts) which are either discarded or burned as fuel (Jahanban- Esfahlan et al., 2020). Nevertheless, under a circular economy approach, these wastes can be valorised to obtain lignin, due to their high lignin content by mass (approximately 40% of the total) (Jahanban-Esfahlan et al., 2020). Therefore, this study aims to environmentally analyse two different sequences of lignin extraction through the valorisation of walnut shells, considering the Life Cycle Assessment methodology. Lignin production involves the following steps: autohydrolysis, delignification, solid cleaning and precipitation. In the organosolv process, an ethanol/water mixture (70/30, v/v) is used at 200°C in a solid/liquid ratio of 1:6 while the soda process is carried out at 121°C using a 7.5% NaOH solution by weight as reagent in the same solid/liquid ratio as in the organosolv method (Fernández-Rodríguez et al., 2021). The valorisation system based was simulated with the use of Aspen Plus® software (Aspentech, 2020) and 100 kg of walnut shells were taken as the biomass input stream. The environmental study considered one kilogram of lignin as the target product, under a cradle-to-gate approach. The inventory is based on data taken from the simulation software. The environmental results suggest that the scenario based on the organosolv process presents the worst environmental profile for all impact categories mainly due to the total thermal energy required in the plant, requiring approximately five times more energy in this scenario than in the soda scenario. In addition, it is observed that the main equipment consuming the most thermal energy is the distillation column at the final stage of the valorisation process to recover the solvent for recirculation and the equipment for heating the large quantities of water needed in the autohydrolysis stage. As future work, it is proposed to reuse the internal streams of the valorisation plant to reduce the loads generated by the energy requirement as well as the use of renewable energy sources instead of using the national energy grid. -Aspentech, 2020. Aspen Plus. URL https://www.aspentech.com/products/engineering/aspen-plus/ (accessed 3.31.20). -FAO, 2013. Food wastage footprint: Impacts on natural resources - Summary report. -Fernández-Rodríguez, J., Erdocia, X., Alriols, M.G., Labidi, J., 2021. Techno-economic analysis of different integrated biorefinery scenarios using lignocellulosic waste streams as source for phenolic alcohols production. J. Clean. Prod. 285. https://doi.org/10.1016/j.jclepro.2020.124829 -Jahanban-Esfahlan, A., Jahanban-Esfahlan, R., Tabibiazar, M., Roufegarinejad, L., Amarowicz, R., 2020. Recent advances in the use of walnut (: Juglans regia L.) shell as a valuable plant-based bio-sorbent for the removal of hazardous materials. RSC Adv. 10, 7026–7047. https://doi.org/10.1039/c9ra10084

Encompassing health and nutrition with the adherence to the environmentally sustainable New Nordic Diet in Southern Europe

The partnership for sustainable and healthy food is a challenge shared by governments, food industry, environmental science, and the health service. At the European level, the application of policies based on the Mediterranean-style eating pattern is recommended. In this regard, attention is being paid to the New Nordic Diet (NND), which shares many similarities with the Mediterranean one but comprises typical foods from Nordic countries. Therefore, it could be transferred to anywhere in the world, including Spain, where it would coexist with the recommendations of the Mediterranean Diet (MD) and the southern European Atlantic Diet (SEAD). The main objective of this study is to propose the modelling of the health, economic, environmental and nutritional indicators of the southern version of NND (SNND) and to compare, when possible, the results with those of the alternatives. The environmental metrics for SNND, carbon footprint (CF) and water footprint (WF), were estimated at 3.58 kg CO2·person−1·day−1 and 3528 L·person-1·day-1 respectively, a slightly worse environmental profile than for MD. In relation to economic metrics, the updated cost index to 2019 was 4.30 €·person−1·day−1, similar to MD and lower than for SEAD. The overall dietary quality score was 126, a higher result than the baseline (100), but worse than those identified for SEAD and MD. In terms of health outcomes, NND showed benefits that reduce non-communicable diseases such as the risks of type 2 diabetes mellitus (T2D) by 31%, colorectal cancer (CRCA) by 35% and cardiovascular disease (CVD) by 7%. Compliance with the NND was also associated with a weight loss of 1.83 kg per person following the diet. Epidemiological evidence supported greater weight loss when following the NND, but greater reductions in the CVD risk when adhering to MD. The dissemination through educational campaigns of these recommended dietary patterns and the incorporation in the dietary guidelines of simple indicators of nutritional quality, environmental impacts and health, easily understood by a wide audience, is one of the most important challenges of public and environmental healthC.C–F would like to show her gratitude to the Spanish Ministry of Science, Innovation and Universities (Grant reference FPU 19/06648). S.G-G. would also give thanks to the Spanish Ministry of Economy and Competitiveness (Grant reference RYC-2014-14984). C.C., S.G.-G., G.F. and M.T.M. belong to the Galician Competitive Research Group GRC 2013–032 and to Cross-disciplinary Research in Environmental Technologies (CRETUS Research Center, ED431E 2018/01). All these programs are co-funded by Xunta de Galicia and FEDER (EU)S

Carbon footprint and nutritional quality of different human dietary choices

Apart from industrial activities, our eating habits also have a significant environmental cost associated with crop cultivation, manufacturing processes, packaging, refrigeration, transport cooking and waste management. In a context of growing social awareness of the role of different dietary choices in the environment, the review of different alternatives on the road to a healthy and sustainable diet should integrate relevant information on the nutritional quality of different eating habits. Since dietary choices have an effect on environmental sustainability and human health, a literature review on different dietary choices has been conducted to determine the differences in carbon footprint and nutritional quality identifying the main hotspots trying to give advice towards the identification of sustainable diets. After applying a set of criteria for reference selection, 21 peer-reviewed studies have been analysed in detail, allowing the comparison of 66 dietary scenarios. We identified that the so-called Mediterranean and Atlantic diets present high nutritional scores and low carbon footprints. On the contrary, the dietary choices identified in northern and Western Europe, as well as in the United States, have the highest carbon footprints, highlighting the contribution of dairy products as a basic source of high-quality nutrients and protein. Broadly speaking, dietary choices rich in vegetables (e.g., vegan, vegetarian as well as Indian and Peruvian) have a better environmental profile than those rich in meat (mainly ruminant meat). In line with these findings, the shift in meat consumption habits from beef and veal to chicken, pork and poultry, the introduction of alternative foods to animal protein (e.g. quinoa) and the consumption of olive oil as a major source of vegetable oil may be compatible with a healthier and more environmentally friendly diet. However, the complete elimination of meat and dairy products from the daily diet may not be feasible in case the supply of some micronutrients (e.g., calcium and vitamin D) is not guaranteed. Limitations were identified in the consulted studies related to the consideration of the different system boundaries, as well as underlying uncertainties related to data sources. Therefore, efforts should be made to develop consistent and agreed-upon methods for estimating both the carbon footprint and nutritional quality scoresThis research has been supported by a project granted by Xunta de Galicia (project ref. ED431F 2016/001). Dr. S. González-Garcia would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for financial support (Grant reference RYC-2014-14984). The authors belong to the Galician Competitive Research Group GRC 2013-032 as well as to CRETUS (AGRUP2015/02), co-funded by Xunta de Galicia and FEDER (EU)S

Is the Paleo diet safe for health and the environment?

It is no secret that the world is facing the challenge of transitioning to healthy diets, which link human and planetary health and the economy. Among the wide variety of diets, Palaeolithic diet has become so popular in social media. The main goal of this study is to evaluate the environmental and health sustainability of the Paleo diet, incorporating the health dimension to the economic, nutritional, and environmental indicators. Results were compared with those of the other dietary patterns in Spain: Mediterranean Diet (MD), Southern European Atlantic Diet (SEAD) and the Spanish Dietary Guidelines (NAOS). It was concluded that the Paleo diet is a diet low in carbohydrates (24.5% of energy intake) and high in protein (29.6% of energy intake), cholesterol (835 mg·day−1) and polyunsaturated fatty acids (15.3% of energy intake). The diet quality score was 260, a result above the recommended. Regarding the health assessment of the food categories that contribute most to the Paleo diet, vegetables and fruits were associated with a lower risk of cardiovascular disease (CVD), type 2 diabetes mellitus (T2D), colorectal cancer (CRCA), obesity and stroke. The opposite result was observed for red meat. Fish and seafood, as well as poultry, were associated with a relative risk higher than one for T2D and obesity, but not for CVD, CRCA or stroke. Based on the economic assessment, a higher dietary cost was estimated for Paleo diet (8.6 €·person−1·day−1). The environmental metrics in terms of carbon footprint (CF) and water footprint (WF) were estimated in 5.44 kg CO2·person−1·day−1 and 3499 L·person−1·day−1 respectively, a worse environmental profile than that of MD, SEAD and NAOS. Environmental and health sustainability assessments can help policy makers set targets for improving dietary guidelines at national level. They are recognized as a very useful tool to guide citizens towards the most appropriate dietC.C.-F. would like to express her gratitude to the Spanish Ministry of Science, Innovation and Universities for financial support (Grant reference FPU 19/06648). S.G.-G. would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for financial support (Grant reference RYC-2014-14984). C.C-F, S.G.-G., G.F. and M.T.M. belong to the Galician Competitive Research Group GRC 2013-032 and to CRETUS Strategic Partnership (AGRUP2015/02). All these programs are co-funded by FEDER (EU)S

Driving commitment to sustainable food policies within the framework of American and European dietary guidelines

Diet and nutrition are essential factors in promoting good health throughout life. Their role as determinants of chronic non-communicable diseases is widely recognized. Additionally, the demand for food involves relevant environmental burdens that have to be taken into account on the way to achieving the Sustainable Development Goals. As an important part of nutrition policy, food-based dietary guidelines (FBDGs) have been revised. The key question is: Are environmental considerations being incorporated into them? To address this issue, we modeled and compared both the main environmental indicators in terms of carbon footprint (CF) and water footprint (WF), and nutritional quality (according to the Nutrient Rich Diet index, NRD9.3 and a health gain score) of dietary guidelines from Northern and Southern Europe and America. Particularly, the FBDGs compared were Dutch Dietary Guidelines (DDG), New Nordic Diet (NND), Spanish Strategy for Nutrition, Physical Activity and Obesity Prevention (NAOS), Mediterranean Diet (MD), Italian Dietary Guidelines (IDG) and American Dietary Guidelines (DGA). The IDG and MD offered the best profiles from a climate change perspective (2.04 and 2.21 kgCO2eq·day−1). Overall, DGA had the highest CF (2.98 kgCO2eq·day−1). WF presented greater fluctuations, not only due to daily-recommended amounts, but also because of different climate conditions and production systems of the reference countries. Hence, WF ranged from 1760 L·person−1·day−1 in IDG to 3181 L·person−1·day−1 in NAOS. Finally, the nutritional value of MD, which had the highest NRD9.3 (477) and health gain score (178), has been demonstrated when the comparison was made with DDG, the one with the lowest health gain score (97) and DGA, the worst in terms of NRD9.3 (391). To go ahead of the FBDGs that bet on all dimensions of sustainability, multi-criteria analysis is needed. Nutrition and environmental performance are not the only aspects of the problem; economy and sociocultural variables should be consideredC.C.-F. would like to express her gratitude to the Ministry of Science, Innovation and Universities for financial support (Grant reference FPU 19/06648). S.G.-G. would like to express her gratitude to the Ministry of Economy and Competitiveness for financial support (Grant reference RYC-2014-14984). C.C-F, S.G.-G., G.F. and M.T.M. belong to the Galician Competitive Research Group (GRC ED431C 2017/29) and to the Cross-disciplinary Research in Environmental Technologies (CRETUS Research Center, ED431E 2018/01). All these programs are co-funded by FEDER (EU)S

Environmental comparison of banana waste valorisation strategies under a biorefinery approach

Banana wastes can be valorised in bioethanol due to its high content in cellulose (more than 30% of total on a dry basis) and hemicelluloses (25% of total). Large amount of these wastes is generated during the banana cultivation and harvesting stage. This study proposes the use of, beside conventional acid sulphuric, different organic acids (tartaric, oxalic and citric) during acid pretreatment step, to suppress the unwanted compounds formation and improve bioethanol production. Instead, bioethanol production generates a solid waste flow that is managed in an anaerobic digestion plant, obtaining biogas, to be converted into energy, and digestate, considered as a potential biofertiliser. Life cycle assessment methodology is used to analyse the environmental profiles of four valorisation scenarios to produce bioethanol from banana peel waste. According to the results, reported per kilogram of bioethanol, the citric acid-based scenario has the worst environmental profile due to the background processes involved in the acid production (around 55% for most impact categories). Conversely, the oxalic acid-based scenario has the best environmental profile, with a decrease of around 20% and 35%, depending on the impact category, compared to the citric acid scenario. The energy requirements production (mostly thermal energy) is the main hotspot in numerous subsystems regardless of the scenario (ranging from 30% to 50% depending on the impact category). Therefore, the use of renewable energy sources to satisfy energy requirements combined with an energy optimisation of the valorisation strategies through the reuse of some internal steams, is proposed as improvement activitiesThis research has been partially supported by the SENSE project granted by FEDER/Spanish Ministry of Science, Innovation and Universities, Spanish National Research Agency (CTQ2016-75136-P) and by the project Enhancing diversity in Mediterranean cereal farming systems (CerealMed) funded by PRIMA Programme and FEDER/Ministry of Science and Innovation – Spanish National Research Agency (PCI2020-111978). B. Santiago thanks to the Spanish Ministry of Science, Innovation and Universities for financial support (Grant reference BES-2017-081715). The authors belong to the Galician Competitive Research Group GRC 2013-032 and to CRETUS Strategic Partnership (AGRUP2015/02). All these programmes are co-funded by Xunta de Galicia and FEDER (EU)S

Identifying the sustainability route of asparagus co-product extraction: from waste to bioactive compounds

Rutin is a flavonol glycoside that is found in greater proportion in asparagus stalks. Considering the possibility of valorization of solid waste from the food industry, this research aims to evaluate and compare the environmental profile of the different schemes of rutin asparagus extraction. Specifically, Soxhlet, pressurized liquid and supercritical fluid extractions, all of them using ethanol as the extracting agent. The environmental analysis is conducted according to the Life Cycle Assessment methodology under a mass and economic allocation. The results, under economic allocation, show that the scenario based on pressurized liquid extraction have the best environmental profile. However, when mass allocation is considered, the pressurized liquid-based scenario is the worst choice. Consequently, the choice of the solvents will influence the Soxhlet extraction performance. In this regard, ethanol, methanol and ethyl acetate are selected. The solvent comparison identifies ethyl acetate as the extraction agent with the worst environmental profileThis research has been partially supported by the SENSE project granted by FEDER/Spanish Ministry of Science, Innovation and Universities, Spanish National Research Agency (CTQ2016-75136-P) and by the project Enhancing diversity in Mediterranean cereal farming systems (CerealMed) funded by PRIMA Programme and FEDER/Ministry of Science and Innovation – Spanish National Research Agency (PCI2020-111978). B. Santiago thanks to the Spanish Ministry of Science, Innovation and Universities for financial support (Grant reference BES-2017-081715). Dr. S. González-Garcia would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for financial support (Grant reference RYC-2014-14984). The authors belong to the Galician Competitive Research Group GRC 2013-032 and to CRETUS Strategic Partnership (AGRUP2015/02). All these programmes are co-funded by Xunta de Galicia and FEDER (EU)S

Formulation of Laccase Nanobiocatalysts Based on Ionic and Covalent Interactions for the Enhanced Oxidation of Phenolic Compounds

Oxidative biocatalysis by laccase arises as a promising alternative in the development of advanced oxidation processes for the removal of xenobiotics. The aim of this work is to develop various types of nanobiocatalysts based on laccase immobilized on different superparamagnetic and non-magnetic nanoparticles to improve the stability of the biocatalysts. Several techniques of enzyme immobilization were evaluated based on ionic exchange and covalent bonding. The highest yields of laccase immobilization were achieved for the covalent laccase nanoconjugates of silica-coated magnetic nanoparticles (2.66 U mg−1 NPs), formed by the covalent attachment of the enzyme between the aldehyde groups of the glutaraldehyde-functionalized nanoparticle and the amino groups of the enzyme. Moreover, its application in the biotransformation of phenol as a model recalcitrant compound was tested at different pH and successfully achieved at pH 6 for 24 h. A sequential batch operation was carried out, with complete recovery of the nanobiocatalyst and minimal deactivation of the enzyme after four cycles of phenol oxidation. The major drawback associated with the use of the nanoparticles relies on the energy consumption required for their production and the use of chemicals, that account for a major contribution in the normalized index of 5.28 × 10−3. The reduction of cyclohexane (used in the synthesis of silica-coated magnetic nanoparticles) led to a significant lower index (3.62 × 10−3); however, the immobilization was negatively affected, which discouraged this alternativeThis work was financially supported by the Spanish Ministry of Economy and Competitiveness (CTQ2013-44762-R and CTQ2016-79461-R, program co-funded by FEDER). The authors belong to the Galician Competitive Research Group GRC 2013-032, program co-funded by FEDER. Yolanda Moldes-Diz thanks the Spanish Ministry of Economy and Competitiveness for her predoctoral fellowshipS

Linking environmental sustainability and nutritional quality of the Atlantic diet recommendations and real consumption habits in Galicia (NW Spain)

Today's society is increasingly aware of food consumption patterns. Under the perspective that real consumption trends are often not in line with healthy recommendations, this research focuses on the study of the environmental and nutritional sustainability of two types of food consumption habits present in the northern Atlantic area of Spain (Galicia). The main objective is, therefore to detect the existing deviations between the current Galician diet (GD) and the traditional and increasingly relevant Recommended Atlantic Diet (RAD), allowing verifying whether current consumption patterns ensure an optimal and sustainable nutritional profile. In this sense, the carbon footprint from a Life Cycle Assessment perspective has been estimated as environmental indicator of both dietary patterns and, the nutritional quality has been determined by the Nutrient Rich Diet 9.3 index and the Health gain score. The carbon footprint of both dietary models is moderately high compared to recommended diets such as the Mediterranean one. Comparing the two scenarios, the associated greenhouse gas emissions are about 15% higher for GD than for RAD, mainly due to the higher intake of beef and dairy products. On the other hand, nutritional quality is comparatively higher for RAD than for GD, associated with higher consumption of vegetables and fruits. An additional objective of this work has been to consider a sensitivity analysis to determine the effect of replacing beef with alternative sources. Having in mind this study, it can be concluded that the real consumption pattern in Galicia is far from the recommended one, with worse environmental and nutritional quality. The promotion of social awareness policies to guide consumers in the choice a healthier and more environmentally sustainable dietary pattern should be advisable for regional decision-makers as well as for those who wish to promote adherence to the Atlantic diet in other regions and countriesThis research has been supported by a project granted by Xunta de Galicia (project ref. ED431F 2016/001). Dr. S. González-Garcia would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for financial support (grant reference RYC-2014-14984). The authors belong to the Galician Competitive Research Group GRC 2013-032 as well as to CRETUS (AGRUP2015/02), co-funded by Xunta de Galicia and FEDER (EU)S