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•LCA & LCC combination provided key elements for sustainable waste policy-making.•High grade recycling can be more sustainable than low grade recycling.•Transports distances and price ...of recycled aggregates are the main environmental and economic drivers.•The most sustainable solution can be the one with highest economic cost.
Urgent solutions are needed in Europe to deal with construction and demolition waste (CDW). EU policy has contributed to significantly reducing the amount of CDW going to landfill, but most of the effort has been put in downcycling practices. Therefore, further policies are needed to stimulate high-quality recycling of CDW.
The present paper presents a combined life cycle assessment (LCA) and life cycle costing (LCC) methodologies to analyse the environmental and the economic drivers in four alternative CDW end-of-life scenarios in the region of Flanders, in Belgium. The four analysed alternatives are (i) landfilling, (ii) downcycling, (iii) advanced recycling and (iv) recycling after selective demolition.
LCA results show that landiflling is the scenario having the highest environmental impacts in terms of person equivalent (PE), followed by downcycling and recycling (-36%) and recycling after selective demolition (−59%). The decrease in environmental impacts is mostly due to the avoided landfilling of CDW and the recovery of materials from selective demolition. LCC results indicate that landfilling is the scenario bearing the highest total economic costs. This is due to the high landfill tax in Flanders. The recycling after selective demolition bears the second highest cost.
The increase of high-quality CDW recycling can significantly reduce the overall environmental impact of the system. Implementing a high landfill tax, increasing the gate fee to the recycling plant, and boosting the sales price of recycled aggregates are the most effective drivers to facilitate a transition towards a more sustainable CDW management system.
The paper demonstrates that the combined LCA and LCC results can highlight the environmental and economic drivers in CDW management. The results of the combined analysis can help policymakers to promote the aspects contributing to sustainability and to limit the ones creating a barrier.
Efficiency assessments of marine ingredient use in aquaculture are required to fully understand their contribution to global seafood supply and their impacts on all UN Sustainable Development Goals. ...Fish In: Fish Out (FIFO) ratios have become the principal metric used to ensure aquaculture does not negatively impact wild fish stocks. However, several approaches have been advocated to calculate the FIFO ratio and there have been criticisms that the different approaches employed lead to over- or under- estimates of the dependence of aquaculture on marine ingredients. Critically, FIFO does not align with Life Cycle Assessment as a measure of other environmental impacts. In this paper we present an alternative method to calculate the FIFO ratio based on the principle of economic allocation (economic Fish In: Fish Out – eFIFO) as commonly used in Life Cycle Assessments. Economic allocation acts as a proxy for the nutritional value of ingredients and places higher importance on the more limiting co-products generated and their relative demand. Substitution of marine ingredients by alternate feed ingredients has significantly reduced the amount of fishmeal and fish oil in aquafeed formulations for most farmed fish species, resulting in a continually decreasing FIFO ratio. Results show that most aquaculture species groups assessed in this study are net producers of fish, while salmon and trout aquaculture are net neutral, producing as much fish biomass as is consumed. Overall, global fed-aquaculture currently produces three to four times as much fish as it consumes. Tracking historical prices of fish oil against fishmeal, the relative higher price of fish oil leads to relatively higher allocation of fish to fish oil compared to fishmeal. This leads to relatively higher eFIFO for species with high fish oil requirements.
•Economic allocation is applied to the co-production of fishmeal and fish oil to assess the fish in: fish out (FIFO) ratio.•Economic allocation avoids double counting of fish resources.•Economic allocation gives a higher impact to the limiting feed ingredient, reflecting socio-economic drivers of fisheries.•The economic FIFO (eFIFO) ratio is compared to previously published FIFO ratios for the main aquaculture species groups.
This study presents a Life Cycle Assessment (LCA) of photovoltaic (PV) electricity production in Italy based on the composition of the current and future Italian PV scenario.
Using detailed and ...site-specific data, the actual composition of the Italian mix of PV technologies at the end of 2022 and those expected for 2030 were defined.
A new LCA modelling of the most relevant PV technologies was carried out using updated and reliable inventory data. The impact assessment was performed adopting the most relevant impact categories of Environmental Footprint Method v. 3.1.
The environmental profiles of the two Italian PV scenarios (PV Scenario_2021 and PV Scenario_2030) analysed in this study were compared with that of the PV scenario achievable using unaltered Ecoinvent v 3.9.1 datasets specific to Italian. The obtained results highlighted that the use of Ecoinvent datasets and hypothesis entails a significant overestimation of the environmental impacts of photovoltaic electricity production in Italy; showing higher impacts ranging from 70 % to 30 % (depending on the impact category considered) and the main key factors affecting the results were investigated. However, the wide impacts gaps pointed out the importance of conducting representative LCA studies of the fast-growing and evolving PV context of the countries, to provide reliable impact results to policy makers and to other researchers and who need to include the PV electricity generation in their studies.
Furthermore, the environmental performance analysis of the two Italian PV scenarios highlighted the higher sustainability of the PV electricity production in the next years (PV Scenario_2030) for all considered impact categories (except for land use). This improvement can be primarily attributed to the higher annual energy yield and the greater utilization of high-efficiency PV technologies, along with the expansion of ground-mounted PV plants.
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•The actual and future composition of Italian photovoltaic (PV) mix was determined.•A new LCA modelling of all PV technologies was conducted with updated inventory data.•Ecoinvent v 3.9.1 PV scenario showed higher impacts ranging from 70 % to 30 %.•Energy yield and module efficiency were the main key factors affecting LCA results.•Except for land use ground-mounted PV systems were more sustainable than rooftop ones.
The development of biofuels has been considered as an important countermeasure to abate anthropogenic CO2 emissions, suppress deteriorated atmospheric greenhouse effect, and mitigate global warming. ...To produce biofuels from biomass, thermochemical conversion processes are considered as the most efficient routes wherein torrefaction has the lowest global warming potential. Combustion is the easiest way to consume biomass, which can be burned alone or co-fired with coal to generate heat and power. However, solid biomass fuels are not commonly applied in the industry due to their characteristics of hygroscopic nature and high moisture content, low bulk density and calorific value, poor grindability, low compositional homogeneity, and lower resistance against biological degradation. In recently developing biomass conversion technologies, torrefaction has attracted much attention since it can effectively upgrade solid biomass and produce coal-like fuel. Torrefaction is categorized into dry and wet torrefaction; the former can further be split into non-oxidative and oxidative torrefaction. Despite numerous methods developed, non-oxidative torrefaction, normally termed torrefaction, has a higher potential for practical applications and commercialization when compared to other methods. To provide a comprehensive review of the progress in biomass torrefaction technologies, this study aims to perform an in-depth literature survey of torrefaction principles, processes, systems, and to identify a current trend in practical torrefaction development and environmental performance. Moreover, the encountered challenges and perspectives from torrefaction development are underlined. This state-of-the-art review is conducive to the production and applications of biochar for resource utilization and environmental sustainability. To date, several kinds of reactors have been developed, while there is still no obviously preferred one as they simultaneously have pros and cons. Integrating torrefaction with other processes such as co-firing, gasification, pyrolysis, and ironmaking, etc., makes it more efficient and economically feasible in contrast to using a single process. By virtue of capturing carbon dioxide during the growth stage of biomass, negative carbon emissions can even be achieved from torrefied biomass.
Within developing countries, wastewater treatment (WWT) has improved in recent years but remains a high priority sustainability challenge. Accordingly, life cycle assessment (LCA) studies have ...recently started to analyse the environmental impacts of WWT technologies on the specific context of less developed countries, mainly in China and India. This work presents a comprehensive review of this knowledge with the aim of critically analysing the main conclusions, gaps and challenges for future WWT-related LCAs in developing countries. The most commonly assessed technologies in the 43 reviewed articles are different variations of activated sludge and extensive treatments applied in decentralized systems; however, studies focused on advanced technologies or new sources of pollution (e.g. micropollutants) are still lacking. Goal and system boundaries are normally clearly defined, but significant stages for some technologies such as the construction and sludge management are frequently not included and functional units should be defined accordingly to specific conditions in developing countries. At the inventory level, a more concise description of sources and technical parameters would greatly improve the quality of the LCAs along with accountability of direct greenhouse gas emissions. Eutrophication and global warming are the two most commonly assessed impacts; however, the calculation of terrestrial ecotoxicity when the sludge is used for agricultural purposes, of water use and of the land use change impacts associated to extensive technologies should be encouraged. The estimation of more site-specific databases, characterization factors (especially for eutrophication) or normalization and weighting values combined with more affordable access to background databases and LCA software, would deeply increase the accuracy of WWT-related LCAs in developing countries. An increased usage of the uncertainty analysis should be encouraged to assess the influence of these gaps in the final interpretation of the results. The review finishes with a summary of the main challenges and research gaps identified and with specific guidelines for future researchers to avoid the most common shortcomings found in the reviewed studies.
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•First review of WWT-related LCAs in developing countries.•Lack of site-specific characterization factors and normalization/weighting data.•Less than a quarter of the studies include any kind of uncertainty analysis.•Direct GHG emissions and land use are main concerns for extensive treatments.•Future research should focus on advanced technologies or new sources of pollution.
•An economic and environmental assessment of agrivoltaic systems was performed.•Agrivoltaic systems minimise land occupation and stabilise crop yield.•Agrovoltaico has environmental performances ...similar to other photovoltaic systems.•The cost of power from Agrovoltaico is comparable to other photovoltaic systems.•Agrovoltaico contributes positively to 14 of the 17 sustainable development goals.
Agrivoltaic systems are photovoltaic (PV) technologies in which PV panels are mounted at a sufficient height from the ground to enable conventional cultivation practices underneath. Agrivoltaic systems not only preserve agricultural land, but also benefit crop production by improving water use efficiency and reducing water stress. For these positive attributes, the interest over agrivoltaic systems is increasing, but the lack of a thorough environmental and economic analysis of agrivoltaic systems is limiting their implementation. This work aims to fill this gap by modelling the environmental and economic performances of an innovative agrivoltaic system built on tensile structures (Agrovoltaico®) in the Po Valley. The life cycle assessment performed shows that Agrovoltaico systems have environmental performances similar to those of other PV systems in all the areas of environmental concern investigated (climate change, eutrophication, air quality and resource consumption). Agrovoltaico systems show a Levelized Cost Of Electricity comparable to those of ground or roof mounted PV systems, thanks to both the higher productivity of these sun tracking systems and the materials saved by mounting them on a tensile structure. Relying on tensile structures was economically safe and compatible with the current Italian net-metering approach adopted to incentivise PV systems. It is concluded that the economic and environmental costs of Agrovoltaico systems are comparable to those of other PV systems, though the reduced impact on land occupation and the stabilisation of crop production are relevant added values that should be properly valorised in a future energy system dominated by increasing human land appropriation and climate change.
Purpose
Building life cycle assessment (LCA) draws on a number of indicators, including primary energy (PE) demand and global warming potential (GWP). A method of constructing a composite index of ...weighted individual indicators facilitates their use in comparisons and optimization of buildings, but a standard for weighting has not been established. This study investigates the use of monetary valuation of building LCA results as a way to weigh, aggregate, and compare results.
Methods
A set of six recent German office buildings served as a case study. For these, standard LCA and life cycle cost (LCC) calculations were conducted. Monetary valuation models from the literature were investigated as a basis for evaluation. From these, maximum and minimum valuation was chosen and applied to the LCA results for the embedded impacts of the case study buildings. The buildings’ environmental costs (EC) were thereafter calculated and contributions of single impacts are analyzed. The EC—based on external costs—are subsequently compared with the life cycle costs (LCC)—based on market prices—of the respective buildings.
Results and discussion
Of the five standard environmental indicators used in Germany, GWP contributes approximately 80 to 95% of the overall EC. Acidification potential (AP) is the second largest contributor with up to 18%. Eutrophication (EP), photochemical oxidization (POCP), and ozone depletion potential (ODP) contribute less than 2.0%, 1.05%, and 2.4E−6% respectively. An additional assessment of the contribution of resource depletion to EC shows an impact at least as large as the impact of GWP. The relation between the EC and LCC strongly depends on the EC model used: if EC are internalized, they add between 1 and 37% to the life cycle costs of the buildings. Varying construction materials for a case study building shows that materials with low GWP have the potential to lower environmental costs significantly without a trade-off in favor of other indicators.
Conclusions
Despite their sensitivity to the monetary valuation model used, EC provide an indication that GWP and resource depletion—followed by AP—are the most relevant of the environmental indicators currently considered for the construction industry. Monetary valuation of environmental impacts is a valuable tool for comparisons of different buildings and design options and provides an effective and valuable way of communicating LCA results to stakeholders.
To shift towards low-fossil carbon economies, making more out of residual biomass is increasingly promoted. Yet, it remains unclear if implementing advanced technologies to reuse these streams really ...achieves net environmental benefits compared to current management practices. By integrating spatially-explicit resource flow analysis, consequential life cycle assessment (LCA), and uncertainty analysis, we propose a single framework to quantify the residual biomass environmental baseline of a territory, and apply it to the case of France. The output is the environmental threshold that a future large-scale territorial bioeconomy strategy should overpass. For France, we estimate the residual biomass baseline to generate 18.4 ± 2.7 MtCO2-eq·y−1 (climate change), 255 ± 35 ktN-eq·y−1 (marine eutrophication), and 12,300 ± 800 disease incidences per year (particulate matter formation). The current use of crop residues and livestock effluents, being essentially a return to arable lands, was found to represent more than 90 % of total environmental impacts and uncertainties, uncovering a need for more certain data. At present, utilizing residual streams as organic fertilizers fulfills over half of France's total phosphorus (P) and potassium (K) demands. However, it only meets 6 % of the nitrogen demand, primarily because nitrogen is lost through air and water. This, coupled with the overall territorial diagnosis, led us to revisit the idea of using the current situation (based on 2018 data) as a baseline for future bioeconomy trajectories. We suggest that these should rather be compared to a projected baseline accounting for ongoing basic mitigation efforts, estimated for France at 8.5 MtCO2-eq·y−1.
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•Step-wise method for assessing the impacts of residual biomass management strategies•Geo-quantified residual biomass potential coupled with bottom-up LCA, applied for France•The French residual biomass potential is estimated to range between 1664 and 2401 PJ·y−1.•Their current uses generate 18.4 MtCO2-eq·y−1, but heads towards 8.5 MtCO2-eq·y−1.•Only 6 % of the nitrogen content of residual streams is currently substituting synthetic fertilizer.
In response to the climate crisis and ever diminishing global carbon budget targets, managing carbon emissions, particularly during the post-occupancy phase in the building sector, is pivotal. This ...study presents a novel approach that uses a parametric Life Cycle Assessment (LCA) workflow that integrates the temporal dimension to align post-occupancy decision-making with carbon budgets. Applying this method to a French residential case study, this work explores optimization, sensitivity analysis, and different visualization techniques in hopes to inform building actors not only of which carbon mitigation measures to implement, but also when to execute them. The temporal aspect of decision-making proved to be extremely useful as a renovation plan for the remaining building life cycle is proposed. Interestingly however, similar optimization solutions emerged from static and dynamic LCAs despite very distinct Global Warming Potential values, suggesting a possible overlook of dynamic parameters. Findings also illuminate the complexity of conveying multifaceted decision-making information, emphasizing the importance of tailoring solutions. Nonetheless, the specificity of results necessitates further research across varied building typologies. This study is another step towards sustainable building management, underlining the urgency of adhering to carbon budgets.
Nanoscale zero valent iron (nZVI) is globally the main nanomaterial used in contaminated site remediation. This study aims to evaluate the sustainability of using nZVI in the nanoremediation of ...contaminated sites and to determine the factors that affect the sustainability of the use of nZVI in remediation. Five case studies of nZVI use on a pilot scale were selected. Life cycle analysis tools were used to evaluate environmental, economic, social impacts, and sustainability. The functional unit of the life cycle analyses was 1.00 m3 of remediated soil and groundwater. Case study of Brazil was the least sustainable, while case study of United States was the most sustainable. Only the modification of the functional unit results in variations in the sustainability index. Different factors influence the sustainability of nZVI in remediation, the main factor being the amount of nZVI used in the processes. Finally, this work contributes significantly to the state-of-the-art sustainable use of nZVI in remediation. This is a pioneering study in the detailed and comprehensive assessment of the sustainability of the use of nZVI in remediation. Through the analysis of case studies, it is possible to determine the main factors that influence the sustainability of the nZVI remediation life cycle.
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•Life cycle sustainability of nano scale zero valent iron (nZVI) in soil remediation.•Groundwater remediation with nZVI is more sustainable.•Unsaturated soils remediation with nZVI requires more amount of nZVI.•Amount of nZVI used in remediation affects sustainability.
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