With the rapid development of the construction industry, it is necessary to synthesize environment-friendly functional polymers, especially when developing “green” construction industry types. Herein ...a novel solid-state polycarboxylate superplasticizer (PCE) with low energy-consumption was designed and synthesized. In industrial application, solid-state PCE has exhibited better cement paste fluidity and concrete slump compared to liquid-state PCE. A life cycle assessment (LCA) of the PCE synthesis, the packaging materials used, and the transportation of the PCE were conducted based on the ReCiPe method. The results indicated that liquid-state PCE has a far greater environmental impact at >60% than solid-state PCE, which is less significant at <40%. The inventory data that are associated with the production of the new polymer are disclosed for the first time to enrich the related database in this field. This study demonstrates the optimization of the state and synthesis technique of a functional polymer, improving the performance and lowering the environmental impacts involved in producing the polymer, while reducing the risks to human health and protecting the ecosystem at the same time.
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•A green chemistry and green technical processes for PCE are established.•Solvent-free system is a potential technique to achieve sustainability goals.•Low temperature synthesis of solid-state PCE show better application performance.•Normalization done to recommend best process options and lowest environmental impact.•A cradle-to-gate LCA of the synthesized PCE has been carried out.
Circular economy (CE) is aimed at redressing the negative impacts on the environment from linear economic models. CE should consider the economic and environmental dimensions; however, in most cases, ...these have been addressed separately. CE discourses have focused mainly on the environmental dimension and assumed that all material loops must be closed. Despite the calls to engage with CE, there has been extremely limited research on decision‐making for CE. The following steps were followed in the decision‐making for CE framework construction and design: (1) reviewing the literature; (2) considering economic data approaches; (3) accounting for material flows; (4) modifying the fungibility approach to focus on the environmental dimension; (5) considering environmental impacts; and, (6) selecting a decision tree format. This paper combines the economic fungibility (probability of recovery and price), environmental impacts fungibility (probability of recovery and environmental impacts) to develop the ‘Decision‐making tree for circular economy’ framework. The decision‐making tree for circular economy is aimed at providing guidance on which and how to close loops depending on economic considerations, environmental impact, and probability of recovery of materials. The CE decision‐making tree provides eight options to help decide which and how to close such loops, and help decide which material loops should be eliminated, closed, or remain open. Decision‐making is key to deciding which loops to close to engage with CE more efficiently.
Life cycle assessment was carried out for a conventional wooden furniture set produced in Mardan division of the Khyber Pakhtunkhwa province of Pakistan during 2018-19. Primary data regarding inputs ...and outputs were collected through questionnaire surveys from 100 conventional wooden furniture set manufacturers, 50 in district Mardan and 50 in district Swabi. In the present study, cradle-to-gate life cycle assessment approach was applied for a functional unit of one conventional wooden furniture set. Production weighted average data were modelled in the environmental impacts modelling software i.e., SimaPro v.8.5. The results showed that textile used in sofa set, wood preservative for polishing and preventing insects attack and petrol used in generator had the highest contribution to all the environmental impact categories evaluated. Total cumulative energy demand for wooden furniture set manufactured was 30,005 MJ with most of the energy acquired from non-renewable fossil fuel resources.
In spite of almost two decades of experience, Strategic Environmental Assessment's (SEA) foundations remain unclear to the point that the case for needing an instrument called ‘SEA’ could be ...questioned. The aim is to ask: what problems was SEA meant to solve, and what needs was it meant to address, by reflecting on the strengths and weaknesses of SEA thinking to date. I do so by organising the reasons and arguments offered by scholars and practitioners under three ‘lines of argumentation’ related to the strategic dimension of SEA, its methods and purpose. I explore how each line of argumentation affects the concept of (the purpose and role) and approach to (the procedures, methods and tools) SEA. The problematisation of these arguments and their evolution makes a case for the urgent acknowledgment of misleading simplifications. From this analysis I propose a number of promising fields of inquiry that could help respond to the growing expectations attached to SEA and strengthen its ‘strategic’ dimension: revisiting the concept of assessment in SEA, promoting strategies for the introduction of SEA, and strengthening the contribution of theory to SEA practice.
Tidal energy has the potential to form a key component of the energy production in a number of countries, including the UK. Nonetheless, the deployment of tidal energy systems is associated with ...potential environmental impacts as prime resource sites often coincide with unique ecosystems inhabited by sensitive organisms. Previous studies have generally focused on the hydrodynamic impact of tidal energy schemes, i.e. how schemes alter the flow dynamics and sedimentary transport processes. Whilst these efforts are key in understanding environmental impacts, there is no straightforward step for translating sediment to faunal changes. Species distribution models offer methods to quantitatively predict certain possible impacts of tidal energy extraction. The River Severn is a distinguished candidate region for tidal energy in the UK featuring sites under stringent ecological protection regulations. We examine the impact of a proposed Severn tidal barrage on 14 species via the linking of hydrodynamic modelling to species distribution models. Through a selection of species that are linked via a simple food web system we extrapolate changes in prey species to the respective predator species. We show that species at lower trophic levels would be adversely affected by the barrage, but higher trophic level organisms increase in possible habitable area. Once food web relationships are acknowledged this increase in habitat area decreases, but is still net positive. Overall, all 14 species were affected, with most gaining in distribution area, and only four losing distribution area within the Severn Estuary. We conclude that a large-scale tidal barrage may have detrimental and complex impacts on species distribution, altering food web dynamics and altering food availability in the Severn Estuary. The methodology outlined herein can be transferred to the assessment and optimisation of prospective projects globally to aide in the sustainable introduction of the technology.
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Graphene oxide (GO)-enhanced membranes are being developed to solve major limitations in both reverse osmosis (RO) and membrane distillation (MD) technologies, which include high electricity and ...thermal energy consumption. This study performed, for the first time, a life cycle assessment to determine the effects of using GO-enhanced membranes on the environmental impacts of seawater desalination via RO and MD. Four scenarios were evaluated and eighteen environmental impacts were quantified according to the ReCiPe impact assessment method. The average impacts for the RO-GO scenarios were lower than those of RO by 3–7 %. The reduction in the climate change impact was 3–8 %, which could avoid the release of 380–850 kt CO2 eq. per year globally if these membranes were used in current seawater RO systems. The MD-GO scenarios had, on average, 27–34 % lower impacts than the MD scenarios. Overall, the RO-GO systems were the most favourable, with lower impacts than MD-GO for most categories. However, using solar-thermal energy instead of natural gas in MD desalination would lead to 43–93 % lower impacts in nine categories than RO powered predominantly by fossil fuels. This includes climate change, which would be 64 % lower; however, freshwater ecotoxicity would be more than four-times higher. The results of this work indicate the potential environmental benefits of GO-enhanced membranes and discuss the future developments needed to improve the performance of RO and MD.
•Graphene oxide reduces environmental impacts of membrane distillation by 27–34 %.•The reduction is much smaller for reverse osmosis (3–6.8 %).•Still, that would avoid emissions of 380,000–850,000 t CO2 eq. per year globally.•Reverse osmosis has much lower impacts than membrane distillation.•However, using renewable heat would make membrane distillation a better option.
The objective of this study was to develop a novel methodology that enables pig diets to be formulated explicitly for environmental impact objectives using a Life Cycle Assessment (LCA) approach. To ...achieve this, the following methodological issues had to be addressed: (1) account for environmental impacts caused by both ingredient choice and nutrient excretion, (2) formulate diets for multiple environmental impact objectives and (3) allow flexibility to identify the optimal nutritional composition for each environmental impact objective. An LCA model based on Canadian pig farms was integrated into a diet formulation tool to compare the use of different ingredients in Eastern and Western Canada. By allowing the feed energy content to vary, it was possible to identify the optimum energy density for different environmental impact objectives, while accounting for the expected effect of energy density on feed intake. A least-cost diet was compared with diets formulated to minimise the following objectives: non-renewable resource use, acidification potential, eutrophication potential, global warming potential and a combined environmental impact score (using these four categories). The resulting environmental impacts were compared using parallel Monte Carlo simulations to account for shared uncertainty. When optimising diets to minimise a single environmental impact category, reductions in the said category were observed in all cases. However, this was at the expense of increasing the impact in other categories and higher dietary costs. The methodology can identify nutritional strategies to minimise environmental impacts, such as increasing the nutritional density of the diets, compared with the least-cost formulation.
The concepts of sustainability and circular economy (CE) have attracted enormous attention in the academic, business and political spheres. However, a systematic review of case studies concerning CE ...in the tourism industry remains lacking. The present study collected good environmental management practices and circular solutions related to energy, water and waste from tourist accommodations in Italy/Europe and China. Moreover, sustainable procedures were critically discussed within the strategic water-energy-waste-food-transport (WEWFT) nexus. When comprehensive data were available, good practices were also measured by Circular Indicators (CIs) and compared to benchmark values set by existing certification or labelling. CIs support the innovative, resilient and sustainable development and assessment of the tourism industry. Most of the strategies were focused on energy optimization and a lack of tangible data was depicted for food and waste management.
Climate change is exacerbating environmental pollution from crop production. Spatially and temporally explicit estimates of life-cycle environmental impacts are therefore needed for suggesting ...location and time relevant environmental mitigations strategies. Emission factors and process-based mechanism models are popular approaches used to estimate life-cycle environmental impacts. However, emission factors are often incapable of describing spatial and temporal heterogeneity of agricultural emissions, whereas process-based mechanistic models, capable of capturing the heterogeneity, tend to be very complicated and time-consuming. Efficient prediction of life-cycle environmental impacts from agricultural production is lacking. This study develops a rapid predictive model to quantify life-cycle global warming (GW) and eutrophication (EU) impacts of corn production using a novel machine learning approach. We used the boosted regression tree (BRT) model to estimate future life-cycle environmental impacts of corn production in U.S. Midwest counties under four emissions scenarios for years 2022–2100. Results from BRT models indicate that the cross-validation (R2) for predicting life cycle GW and EU impacts ranged from 0.78 to 0.82, respectively. Furthermore, results show that future life-cycle GW and EU impacts of corn production will increase in magnitude under all four emissions scenarios, with the highest environmental impacts shown under the high-emissions scenario. Moreover, this study found that changes in precipitation and temperature played a significant role in influencing the spatial heterogeneity in all life-cycle impacts across Midwest counties. The BRT model results indicate that machine learning can be a useful tool for predicting spatially and temporally explicit future life-cycle environmental impacts associated with corn production under different climate scenarios.
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•Machine learning demonstrated to be an efficient tool for projecting future life-cycle environmental impacts.•Life-cycle impacts are expected to be higher in future years compared to historical years.•Future life-cycle environmental impacts exhibited substantial spatio-temporal heterogeneity.•Precipitation and temperature played key roles in spatio-temporal heterogeneity of life-cycle impacts.•Top polluting counties were identified for potential environmental mitigation strategies.
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