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The aim of this study was to assess the social impacts of microalgae-based systems for wastewater treatment and bioproducts recovery by using the Social Life Cycle Assessment (S-LCA) tool. In particular, two systems were analysed: 1) a system treating urban wastewater, and 2) another system treating wastewater from the food industry. Moreover, these alternatives were compared to 3) a system for bioproducts production from microalgae grown in a standard growth medium. The recovered bioproducts in all the systems considered were: natural pigments, biogas and digestate, which can be reused as biofertilizer. Results showed that the scenario using standard growth medium was the one showing the best results in all impacts and stakeholder categories (up to 24-fold lower impacts depending on the impact category). This was mainly due to: i) the simplicity of the system, which consequently improves health and safety for workers; ii) the absence of contaminants which consequently improves health and safety, acceptability and olfactory impact for both consumers and the local community; iii) the presence of well-established legislation, regulatory frameworks, and full-scale deployment, which benefit value chain actors and society. Overall, this study also identified several social factors hindering a transition towards a circular bioeconomy in the microalgae-based systems for the wastewater treatment and resource recovery sector. [Display omitted] • Social Life Cycle Assessment of microalgae-based systems was carried out. • Microalgae-based systems recovered natural pigments, biofertilizer and biogas. • Microalgae-based systems using wastewater and standard growth medium were compared. • Scenario using standard growth medium showed up to 24-fold lower impact. • Bottlenecks for full-scale deployment of microalgae-based systems were identified. [ABSTRACT FROM AUTHOR]

Apart from the importance of Social Sciences and Humanities (SSH) in and of themselves, the potential contribution that they can make to Science, Technology, Engineering and Mathematics (STEM) is huge. Even though some STEM fields have already incorporated SSH elements in their research and education, there are still other disciplines that have not yet approach the intersection between them and SSH. Among these is civil engineering (CE), which has traditionally been set as purely technological and has lacked the inclusion of SSH elements in it. Nonetheless, it is indispensable that engineers have knowledge in SSH to allow them to make decisions more perceptively, realistically and critically. Ultimately, this social understanding can lead them to design and plan solutions that are more socially sustainable. However, there are still no clear guidelines on how to include aspects from social sciences and humanities at the higher education level. This article analyses perceptions, the real status and possible barriers for the incorporation of SSH in the studies of CE. Besides, it analyses and discusses the different methodologies in which engineering students can be introduced to these topics. A triangulation method that combined the use of qualitative and quantitative data was used. Surveys to students, researchers, professors and practitioners were carried out (n=583). Besides, accreditation criteria and CE syllabuses of 100 faculties were reviewed. The analyses showed a dissent between individual perceptions, collective reality and legislative frameworks. Even though the survey responses showed a common agreement concerning the inclusion of SSH, only a minority of CE schools have introduced SSH in their curricula. Besides, accrediting bodies have not yet introduced this as a specific requirement in their criteria. The barriers detected in the incorporation of SSH in CE curricula were: (1) resistance to change, (2) external influences on the curricula, (3) lack of guidelines, (4) misconceptions on what SSH in relation to CE involves. It is necessary to gradually incorporate both hard social skills and soft skills from the beginning of the degree courses and to do so in a transversal way in most of the subjects if professionals and researchers that are capable of designing socially sustainable activities are needed. [ABSTRACT FROM AUTHOR]

The first, and probably the most determining, decision that engineering teams need to make when facing the structural design of any infrastructure is the choice of both an appropriate material and the suitable structural typology for its components. Each component is required to satisfy technical and functional aspects imposed by standards and stakeholder. Currently, the aspects that are most frequently considered in decision-making processes are economic. Nevertheless, environmental and social criteria are also required if one aims at making sustainability-based decisions. In this regard, to the best of the authors' knowledge, very few tools or studies exist that can support decision-makers. The few that do exist, are rather limited, either because they fail to incorporate many relevant factors in the sustainability assessment of a project or because they only evaluate environmental and social impacts of a project as a whole. Although a global assessment is useful to gain a holistic understanding of impacts of a project and to compare them to other projects, it does not necessarily help engineering teams understand the impact of fundamental decisions made when designing individual structural components. Therefore, the aim of the present research paper is to develop a new method for the sustainability analysis of building structural components which has been specifically oriented to beams and girders. This is done by means of the Integrated Value Model for the Evaluation of Sustainability method, which is known by its Spanish acronym, MIVES (Modelo Integrado de Valor para una Evaluación Sostenible). This method draws on multi-attribute utility theory and that allows building an integrated value model as an approach for multi-criteria decision-making. The developed model has been applied to assess the sustainability of different alternatives of beams and trusts to support the non-accessible roof of a sports hall in Vila-seca, Spain. Different material types and structural typologies are analysed. The findings show that the most sustainable alternatives are timber and reinforced concrete trusses, which are actually two options that are seldom used in practice. • A model to evaluate the sustainability of structural elements is developed. • MIVES is proved to be an adequate sustainability assessment tool in these cases. • Girders and trusses made of timber, concrete and steel are analysed. • Timber and concrete trusses achieve the highest global sustainability indexes. [ABSTRACT FROM AUTHOR]

While economic and environmental aspects of civil engineering have attracted the greatest attention among contemporary academy, its social side has frequently been set aside. However, the social impact that infrastructures have is huge and its analysis and understanding are fundamental. At the same time, social aspects such as culture or human behaviour can have significant effects during the different stages of the lifecycle of infrastructures. Therefore, a better understanding of the connections between civil engineering and society can help to better adapt infrastructures to their contexts, as well as minimise their negative impacts; as a result, this understanding can bring about infrastructures that are more socially sustainable. The scarce studies that have assessed the connection between society and civil engineering have considered this relationship as unidirectional. The real scenario is not so simple. The analysis of this relationship needs to be interdisciplinary, and it is in this context that this paper addresses the analysis of infrastructures and of social sciences from a sociotechnical point of view. We draw on the interrelationships found to propose a conceptual framework with the main objective of providing both practitioners and academics with tools to carry out more sustainable and context-adapted decisions. We classify the fields of civil engineering and social sciences into several different subfields, namely six for infrastructures (transport, water, energy, environment, urban planning and buildings) and twelve for social sciences (culture and history, behaviour and mind, communication and interaction, socioeconomics, juridical sciences, life and health, politics, social problems, social groups, ethics and philosophy, arts and education and innovation). Afterwards, we review the existing literature at the intersection between the various categories. We conclude proposing a framework that can support decisions and actions made at different levels and working areas. The framework includes guidelines for a more holistic consideration of the interaction between infrastructures and society in key activities whereby an improved understanding of the effect of this relationship is often required. The guidelines provide a description of different key areas and can be applied to a wide variety of actions ranging from the development of university curricula to the social impact assessment of projects. Image 1 • The dual relationship between civil engineering and social sciences is studied. • Politics and vulnerability are the most studied social areas in civil engineering. • Transport is the most studied civil engineering area from a social perspective. • Infrastructure projects should consider social aspects during all their lifecycles. • A framework and future research directions are proposed. [ABSTRACT FROM AUTHOR]

The design of building foundations has usually been based on tradition, local practice, experience, and structural design codes. Safety is invariably considered the main factor and environmental criteria (or, in general, sustainability) is seldom given due consideration. However, similar safety indicators can be achieved with different variables and a minimum safety factor must always be ensured. The main objective of this study is, from an environmental perspective, to assess the influence of the construction system (cast-in-situ or precast), foundation type (rigid or flexible), and structural code (EC-2 or EHE-08) in the case of a concrete shallow foundation (CSF), using Life Cycle Assessment (LCA). Applying this methodology, the materials (concrete and steel) yielded the highest impacts in all categories, at around 95% for cast-in-situ CSFs and at around 85% for precast CSFs, both in relation to global warming. Consequently, optimization of the amount of these materials is crucial when considering the particular variables selected in this study. The results showed that cast-in-situ and flexible CSFs at moderately shallow depths (and therefore with less steel reinforcement) and precast CSFs with considerable reductions in concrete volumes (due to sloped shapes) had lower environmental impacts. In addition, cast-in-situ CSFs constructed in accordance with the EHE-08 structural code showed lower impacts, while precast CSFs complying with the EC-2 code were environmentally preferable. However, a specific study might be required for specific factors in each case (loads, soil type, structural settlement, among others). Relevant environmental effects associated with the three variables should therefore be given specific consideration in the development of structural design codes and future constructions. [ABSTRACT FROM AUTHOR]

This paper focuses on the sustainability analysis of different constituent materials for sewerage pipes by using a specific multi - criteria decision making (MCDM) method based on the value analysis and the multi-attribute utility theory. The scientific added value of this research consists of developing a method that minimizes the subjectivity involved in the process of quantification and comparison of different alternatives of materials to construct sewerage pipelines. In this context, a requirements tree is defined to derive a non-dimensional sustainability index for each alternative. The method is also supported by use of value functions and weights assigned to each criteria and indicator part of this requirements tree. These value functions were established during seminars and questionnaires solved by specialists and senior managers from the Spanish public sector. Besides, the weights were derived from the use of an Analytical Hierarchical Process. The model is used to assess the sustainability of 8 alternatives including rigid reinforced and non-reinforced concrete pipes as well as flexible polypropylene, polyethylene, polyvinyl chloride and glass-fibre reinforced polyester pipes. Nominal diameters of 400, 800, 1200 and 2000 were chosen as those representatives for urban and rural sewerage networks. The conclusions obtained from the research confirm that the sustainability indexes are similar for diameters of 400 mm and below, independently of the material. In addition, it has been also concluded that concrete solutions are clearly better in terms of sustainability for wider diameters with respect to the other alternative materials. [ABSTRACT FROM AUTHOR]

Vertical farming is emerging as an effective measure to grow food in buildings and can increase food production in urban areas in a more sustainable manner. This study presents a comprehensive environmental assessment of food production in an integrated rooftop greenhouse (i-RTG) – an innovative vertical farm consisting of a rooftop greenhouse connected to a building – and considers rainwater, residual heat (energy), residual air (CO 2 ) and food from an industrial ecology perspective. This synergistic connection preserves resources and improves conditions in the greenhouse and the building. The goal of the study is to show the feasibility of the system and to calculate the environmental impacts from its whole life cycle, from infrastructure to end of life, by comparing these impacts with those of conventional production. The results show that the system is feasible and produced 30.2 kg/m 2 of tomato over 15.5 months. The synergy with the building allows the cultivation of winter-fall crops without supplying heating and maintained an average temperature 8 °C higher than that outdoors. Moreover, rainwater was used to irrigate the crops, reducing consumption from the water supply network by 80–90%. The environmental assessment showed that the operation of the i-RTG has more impacts than the infrastructure (structure of the greenhouse, rainwater harvesting system and equipment) due to the use of fertilisers, which account for 25% of the impacts in four of the six impact categories studied. Regarding the infrastructure, the greenhouse structure and rainwater harvesting system of the building have substantial environmental impacts (over 30% in four of the six impact categories). Comparison with a conventional greenhouse demonstrates that the i-RTG has a better environmental performance, showing between 50 and 75% lower impacts in five of the six impact categories (for instance, 0.58 kg of CO 2 equivalent per kg of tomato vs. 1.7 kg), mainly due to the reduced packaging and transport requirements. From this study, it was concluded that optimisation of the amount of infrastructure material and management of the operation could lead to even better environmental performance in future i-RTG projects. [ABSTRACT FROM AUTHOR]

Stormwater management is essential to reducing the occurrence of flooding events in urban areas and to adapting to climate change. The construction of stormwater Best Management Practices (BMPs) entails a series of life cycle environmental impacts but also implies avoided burdens, such as replacing urban infrastructure after flooding. The aim of this paper is to integrate flood damage prevention into the life cycle assessment (LCA) of BMPs for quantifying their net environmental impact (NEI) and environmental payback (EP) from a consequential LCA standpoint. As a case study, the application of a filter, swale and infiltration trench (FST) in a Brazilian neighborhood was assessed considering a high-intensity rainfall event. The potential avoided impacts were related to cars and sidewalks that were not destroyed due to flooding. In terms of CO 2 eq. emissions, the environmental investment related to the FST was recovered when the destruction of one car or 84 m 2 of sidewalk was prevented. The NEI of the FSTs resulted in significant impact reductions (up to 700%) with respect to not accounting for the avoided products. This approach can be implemented to any type of BMP, and more accurate estimations can be made with data for different events and different types of material damage. [ABSTRACT FROM AUTHOR]

The granite production chain is high energy and water intensive with low resource efficiency. This paper focus on characterizing the potential for environmental improvement of the granite production chain by promoting the optimization of sawing technology, the implementation of rainwater harvesting (RWH) and the material recovery of wasted granite (sludge). The environmental performance of multi-blade gangsaw (MBGS) and diamond multi-wire saw (DMWS) technologies is compared by mean of life cycle assessment. Results demonstrate that DMWS technology contribute 30% of water savings, 40% of energy savings and 80% of material savings per square meter of polished granite tiles (60 x 40 x 2 cm) production. These resource savings contribute together to reduce the product's environmental footprint by 35% to 80%. The potential for RWH is analyzed using Plugrisost® simulation software based on system dynamics. RWH depends on the relationship between rainfall, catchment surface and tank size according to the industrial process’s water demand. The results demonstrate major potential to satisfy over 50% of the systemś daily water requirements using rainwater stored in rainwater tanks of varying capacity. RWH is a sustainable strategy for industrial water cycle management. A comprehensive review of literature reveals a range of technically feasible alternatives to promote material recovery of granite sludge. The ceramic industry is one promising industrial endpoint with which to avoid waste landfilling and contribute to mineral, energy and water savings. This by-product synergy could also serve as starting point for springboarding exchanges with other industrial agents, becoming a global extension of resource efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Until now, few studies had focused on the environmental impact of the construction phase of a drinking water transport and distribution network (DWTDN). Using the life cycle assessment (LCA) methodology, this article compares the environmental impact of pipes made of different materials as constructive solutions for the DWTDN. Two pipe diameters (90 and 200 mm) commonly used in small to medium-sized cities are analysed. The results show that polyvinyl chloride (PVC), high density polyethylene (HDPE) and low density PE have similar environmental impacts in the case of 90 mm pipe diameter. In the case of 200 mm pipe diameter, ductile iron (DI) and glass fibre reinforced polyester show higher environmental impacts than HDPE and PVC, which in the case of DI are between 3 and 11 times higher than those of HDPE for all the midpoint impact categories. Regarding the different construction phases, installation has a higher percentage of environmental impact for 90 mm pipe diameter (40–68% for HDPE in all the impact categories) than for 200 mm pipe diameter (24–57% for an HDPE) due to the difference in the amount of material required for the manufacture of the pipe. The assessment methodology was applied to calculate the environmental burdens derived from a case study. The impact of the different elements of the case study network has been added to obtain the global impact. The potential reduction of the environmental impacts of the case study has been calculated substituting the whole actual network by less impacting constructive solutions. A potential reduction of between 6 and 16% of the impact has been found for the case study, although the savings might be greater in networks with greater abundance of more impacting pipe materials such as DI. This methodology allows the improvement of the network and the design of more eco-efficient DWTDN. [Copyright &y& Elsevier]

Abstract: A life cycle assessment to evaluate the environmental impact of urban sewage sludge use as alternative fuel or raw material in clinker production was carried out. In order to quantify in detail the overall environmental impact of both scenarios, the sewage sludge treatment process and the transport to cement facilities for both alternatives were considered. The substitution ratio of fuel (petcoke) and raw material (limestone) was fixed between 5 and 15% according to the cement production plant limitations. Both scenarios show CO2 savings when compared to the clinker production without substitution. The mid-point and end-point analysis were favourable to the fuel substitution with savings ranging from 3 to 7% compared to the raw material substitution and also to base case without substitution. The influence of the amount of sewage sludge used for both scenarios indicates that fuel substitution reduced the CO2 emissions when the amount of substitution is increased, while other mid-point and end-point categories were proportionally favourable to the fuel substitution scenario. Additionally, the influence of the substituted material characteristics showed that low heating value (fuel substitution) and CaO addition in lime stabilized sludge (raw material substitution) are critical parameters in terms of environmental impact in clinker production. The fuel substitution represents a significant environmental improvement compared to the raw material substitution scenario and clinker production without substitution. [Copyright &y& Elsevier]

Abstract: A cement manufacturing company located in Catalonia (Spain) has upgraded its cement production plant. The new cement production line (L6) has replaced the former lines (L3, L4 and L5) which have been operating for 30 years. The new line production L6 has been designed and constructed taking into account the best available techniques (BAT) for the cement industry. The significant improvements achieved with the new plant are related to the energy efficiency of the new kiln system which represents less amount of fossil fuel and to less emission to the atmosphere per kg of clinker produced. Life-cycle assessment (LCA) methodology has been used for the quantification and evaluation of the environmental impacts of the new production line (L6) considering the designed goals proposed and those achieved at first trimester of 2011 compared to the former production lines. To reduce uncertainty this manuscript presents a cradle-to-gate life-cycle assessment of both scenarios. Analysis using SimaPro 7.2 software shows that new production line (L6) provides a significant reduction of the environmental impact for global warming (5%), acidification (15%), eutrophication (17%) and cumulative exergy demand (13%). The damage assessment also confirmed that new production line (L6) reported a significant reduction impact for the human health (11%), ecosystem quality (11%) and resources (14%) damage compared to the former lines. [Copyright &y& Elsevier]

There is great potential to reduce the environmental impact of the building sector, which is now an area of immense importance, through the optimisation of construction materials and components. This study assesses both the design and the construction of Concrete Deep Foundations (CDFs), which are widely used in construction, from an environmental perspective considering the following variables: (i) grade of prefabrication, i.e., fully cast in situ, partly prefabricated, and fully prefabricated; (ii) compressive strength of cast-in-situ concrete; and (iii) building design codes, i.e., current Spanish codes (EHE-08 and CTE), Eurocode with the Spanish annexes, and Eurocode with the United Kingdom annexes. In addition, the results of Dynamic Load Tests (DLTs) and the economic cost of several CDFs are evaluated. Geotechnical and structural designs of CDFs are carried out along with their life-cycle assessment. Some of the main findings include: (i) partially and fully prefabricated CDFs and conducting DLTs reduced the environmental impact in most categories (by up to 44% for global warming emissions) compared to the fully cast-in-situ CDFs, although they were 12–37% more expensive; (ii) changing the compressive strength of the concrete (in piles and cap) in fully cast-in-situ CDFs from 25 to 35 MPa reduced the environmental impact by up to 14–17% in all categories and economic costs by up to 12%; and, (iii) CDFs with bored piles resulted in the lowest environmental burden when designed with Eurocode and UK annexes (11–31% less impact), as did CDFs with driven piles designed with current Spanish codes (11–18% less impact). The study variables and sensitivity analysis showed a significant effect on the results and should be considered in future construction, research, and building codes. • The prefabrication of Concrete Deep Foundations (CDFs) reduces environmental impact and increases the economic cost. • Increasing the compressive strength of concrete reduces environmental impact and cost. • Conducting Dynamic Load Tests on driven piles reduces environmental impact and cost. • CDFs with bored piles are environmentally better designed with Eurocode with UK annexes. • CDFs with driven piles are environmentally better designed with current Spanish codes. [ABSTRACT FROM AUTHOR]