Recent developments in Life Cycle Assessment

Life-Cycle Environmental Impacts of Additive-Related Chemicals in Polyvinyl Chloride Plastics and the Mitigation Potential

Plastic additive-related chemicals, particularly in polyvinyl chloride (PVC) plastics, have become a key issue in plastic pollution. Although addressing plastic pollution through the life-cycle approach is crucial, the environmental impacts of typical plastic additive-related chemicals in PVC plastics during the cradle-to-gate stage remain unexplored. Consequently, managing the life-cycle environmental impacts of these additives remains challenging. Herein, the environmental impacts of 23 typical plastic additive-related chemicals and six PVC plastic products were evaluated throughout the cradle-to-gate life-cycle stage using a life cycle assessment-material flow analysis (LCA-MFA) coupled model. The results indicate that plastic additives significantly contribute to the environmental impacts of PVC plastic products across various end point indicators, ranging from 8.7 to 40.6%. Additionally, scenario analysis (SA) reveals that conventional strategies for addressing plastic pollution may not be highly effective in mitigating the environmental impacts associated with plastic additives. Specifically, compared to primary polymers, these additives exhibit 4 to 13% lower mitigation potential under the same policy scenarios. However, technical adjustment strategies targeting additives show a mitigation potential of 12 to 39%, suggesting that guiding the plastic additive industry toward green transformation is a key strategy for reducing environmental impacts.

Integrated energy informatics technology on microalgae-based wastewater treatment to bioenergy production: A review

The production of renewable biofuel through microalgae and green technology can be a promising solution to meet future energy demands whilst reducing greenhouse gases (GHG) emissions and recovering energy for a carbon-neutral bio-economy and environmental sustainability. Recently, the integration of Energy Informatics (EI) technology as an emerging approach has ensured the feasibility and enhancement of microalgal biotechnology and bioenergy applications. Integrating EI technology such as artificial intelligence (AI), predictive modelling systems and life cycle analysis (LCA) in microalgae field applications can improve cost, efficiency, productivity and sustainability. With the approach of EI technology, data-driven insights and decision-making, resource optimization and a better understanding of the environmental impact of microalgae cultivation could be achieved, making it a crucial step in advancing this field and its applications. This review presents the conventional technologies in the microalgae-based system for wastewater treatment and bioenergy production. Furthermore, the recent integration of EI in microalgal technology from the AI application to the modelling and optimization using predictive control systems has been discussed. The LCA and techno-economic assessment (TEA) in the environmental sustainability and economic point of view are also presented. Future challenges and perspectives in the microalgae-based wastewater treatment to bioenergy production integrated with the EI approach, are also discussed in relation to the development of microalgae as the future energy source.

Footprints in the scan: reducing the carbon footprint of diagnostic tools in urology

PURPOSE OF REVIEW

There is an ever-growing focus on climate change and its impact on our society. With healthcare contributing a sizeable proportion of carbon emissions, the sector has a duty to address its environmental impact. We highlight the recent progress, current challenges, and future prospects for reducing the carbon footprint in diagnostic urology, specifically for imaging, without compromising patient care.

RECENT FINDINGS

The review is separated into four key areas of recent research: the design of a green radiology department, considering both infrastructural as well as behavioural changes that promote sustainability; individual scanners, where we provide an update on recent technological advancements and changes in behaviour that may enhance sustainable use; responsible resource allocation, where it is important to derive the maximal benefit for patients through the smallest use of resources; the recent research regarding single versus reusable urologic endoscopes as a case example.

SUMMARY

We offer an overview of the present sustainability landscape in diagnostic urology with the aim of encouraging additional research in areas where existing practices may be challenged. To protect the environment, attention is drawn to both more simple steps that can be taken as well as some more complex and expensive ones.

Life Cycle Assessment and Net Energy Analysis of an Integrated Hydrothermal Liquefaction-Anaerobic Digestion of Single and Mixed Beverage Waste and Sewage Sludge

The conversion of biomass to bioenergy is one of the approaches to creating a sustainable society. In this study, the life cycle assessment and the net energy analysis of converting mixed sewage sludge and beverage waste into bioenergy via a combined hydrothermal liquefaction-anaerobic digestion (HTL-AD) system was carried out. Primary sludge (PS), winery rose lees (RL), brewery Trub (BT), the mixture of brewery trub and primary sludge (BTPS) and the mixture of winery rose lees and primary sludge (RLPS) were the feedstocks considered. Efficient energy utilization [in form of net energy ratio (NER)], and environmental emissions were evaluated. The NER of BT (2.07) and RL (1.76) increased when mixed with PS (3.18) to produce BTPS (3.20) and RLPS (2.85). Also, the HTL phase of the combined HTL-AD system produced a greater NER than the AD phase in BT, BTPS, and PS and vice-versa in RL and RLPS. Six environmental impact categories were studied namely global warming, terrestrial acidification, ionizing radiation, terrestrial ecotoxicity, human carcinogenic toxicity, and human non-carcinogenic toxicity. RL produced the greatest environmental impact while BTPS produced the least impact, thus indicating the advantage of feedstock combination. This study shows that the combination of feedstocks for bioenergy production in an HTL-AD system does not only increase the quality and quantity of products but also increases the overall NER as well as reducting the environmental impacts. The study also proved that an integrated HTL-AD system is an energy efficient system with greater resource utilization and less environmental footprint than the constituent systems.

Quantifying carbon footprint of salmon fillet processed in Vietnam: impact of transportation and improvement opportunities

The carbon footprint of a product represents the amount of greenhouse gas (GHG) emissions released during its production, transportation, and consumption and is calculated as carbon dioxide equivalent (CO2-eq). It should be integrated into different existing and future seafood awareness campaigns to create more holistic yardsticks by which consumers, retail businesses, and producers can assess the environmental impacts of seafood. This study used the life cycle assessment (LCA) method for the first time to quantify the carbon footprint of salmon fillet products processed in Vietnam for export. The carbon footprint of 1-kg salmon fillet at the factory gate ranges between 7.20 and 15.05 kg CO2-eq, depending on transportation modes of head-on-gutted (HOG) salmon from Norway to Vietnam. Transportatiton by airfreight doubled carbon footprint of salmon fillet products processed in Vietnam compared to sea freight. Feed and electricity were identified as the two most respective contributing factors during the stage of cultivation, processing fresh salmon in Norway, and the stage of salmon fillet processing in Vietnam. They accounted for about 95% and 50% of the total carbon footprint in these stages of the production chain, respectively. To reduce the carbon footprint of the salmon fillet products processed in Vietnam, the company should (i) make a careful production plan to use sea freight transportation instead of airfreight and (ii) use more electricity from renewable energy sources. Furthermore, the carbon footprint of these products can be reduced by improving the cultivation process via changing feed ingredients and enhancing the feed conversion ratio (FCR).

Modulation of cell death mechanisms via α-Ag2WO4 morphology-dependent factors

The cytotoxic of α-Ag2WO4 synthesized in different morphologies (cuboidal (AW-C), hexagonal rod-like (AW-HRL) and nanometric rod-like (AW-NRL) was analyzed to understand the impact of morphological modulation on the toxicity of 3 T3 cell lines in the dark and when photoactivated by visible light. Pathways of toxicity were examined, such as parameters and electrostatic interaction, uptake, ion release and ROS production. Cytotoxicity was observed for all samples after reaching concentrations exceeding 7.8 μg/mL. Uptake tests demonstrated that the samples were not internalized by cells, likely due to their negative surface charge. AW-NRL exhibited autophagy in the absence of light and during photoactivation, primarily attributed to its ability to generate singlet oxygen. Analyzing intercellular ROS and RNS production, AW-HRL induced an increase in NO through exposure to photo-generated hydroxyl radicals, while AW-NRL showed increases only at non-photoactivated concentrations and AW-C did not exhibit increases. Interestingly, in the dark, these cells showed a low propensity for apoptosis, with late apoptosis and necrosis being more pronounced. When photoactivated, this behavior changed, revealing predominantly apoptotic and late apoptotic cell death. There is a need for an understanding of how morphology can alter the biological properties of α-Ag2WO4 to predict and optimize its effects on cellular responses.

Advances in Chromatographic Analysis of Phenolic Phytochemicals in Foods: Bridging Gaps and Exploring New Horizons

Chromatographic analysis of phenolic phytochemicals in foods has significantly advanced over the past decade (2014-2024), meeting increasing demands for precision and efficiency. This review covers both conventional and advanced chromatographic techniques used for detecting phenolic phytochemicals in foods. Conventional methods like High-Performance Liquid Chromatography, Ultra High-Performance Liquid Chromatography, Thin-Layer Chromatography, and Gas Chromatography are discussed, along with their benefits and limitations. Advanced techniques, including Hydrophilic Interaction Liquid Chromatography, Nano-LC, Multidimensional Liquid Chromatography, and Capillary Electrophoresis, are highlighted for their innovations and improved capabilities. The review addresses challenges in current chromatographic methods, emphasizing the need for standardized and validated procedures according to the Food and Drug Administration, European Cooperation for Accreditation of Laboratories, and The International Organization for Standardization guidelines to ensure reliable and reproducible results. It also considers novel strategies for reducing the environmental impact of chromatographic methods, advocating for sustainable practices in analytical chemistry.

Comparative life cycle assessment of various hydrogen supply methods from Australia to the Republic of Korea in environmental and economic aspects

With the increasing importance of decarbonization to prevent global climate change, hydrogen supply has received considerable attention from several countries, including Korea and Japan, due to the growing demand for the implementation of a hydrogen economy. This study conducted a comprehensive analysis on hydrogen supply methods from Australia to the Republic of Korea in environmental and economic aspects using a life cycle assessment (LCA). The blue hydrogen produced in Australia was considered for import to the Republic of Korea via ocean shipping. The study analyzed the holistic environmental effects in the life cycle of hydrogen ocean transport for various types of hydrogen storage methods (CH2, LH2, LOHC, LNH3, and LNG), as well as alternative marine fuels (MGO, LNG, LPG, CH2, LH2, LNG-LH2, MeOH, and LNH3) for ship transportation. Environmental impact performance was presented in terms of global warming potential (GWP), acidification potential (AP), photochemical ozone creation potential (POCP), eutrophication potential (EP), and particulate matter (PM). For the environmental results, sensitivity studies were conducted to analyze the effects of operating distance and cargo tank size when shipping hydrogen via ocean transport. Additionally, the GWP results of the transportation of green hydrogen and ammonia were compared with those of blue hydrogen and ammonia transport. A cost analysis was performed for the overall processes of hydrogen ocean transport, and the results were included in the study with the estimated hydrogen price for each transportation method.

Industrialization Mitigates Greenhouse Gas Intensity in China's Dairy Sector yet May Prove Insufficient to Offset Emissions from Future Production Expansion

China's dairy farming is undergoing a critical transition from extensive to industrial systems. To achieve sustainable milk production within China's dual-carbon goals, understanding the multidimensional impacts of industrialization on greenhouse gas (GHG) emissions is imperative. This study comprehensively analyzed the implications of China's dairy industrialization on GHG emissions and explored future mitigation potential. Results indicated that industrial systems exhibited lower methane but higher carbon dioxide intensities, with net GHG intensity lower than other systems. During 2002-2020, China's milk production increased by 165%, while GHG emissions increased by 105% to 50.27 Tg CO2eq, accompanying an industrialization rate increased from 16% to 75%. The industrialization progress played a mitigating effect on GHG primarily through intensification within individual production systems before 2008 and transformation between systems post-2008. However, the industrialization's effect was relatively modest compared to other socio-economic factors. By 2030, 11.8 Tg CO2eq will be triggered by predicted milk production growth, but only 0.6 Tg can be offset by system transformation. Integrating measures to improve feed, herd, and manure management on industrial farms could decouple GHG emissions from milk production and achieve a carbon peak before 2030. We suggest transforming to improved industrial systems as a necessary step toward sustainable livestock production.

Life cycle assessment and cost analysis of an innovative automatic system for sorting municipal solid waste: A case study at Milan Malpensa airport

With the recent advancement in artificial intelligence, there are new opportunities to adopt smart technologies for the sorting of materials at the beginning of the recycling value chain. An automatic bin capable of sorting the waste among paper, plastic, glass & aluminium, and residual waste was installed in public areas of Milan Malpensa airport, a context where the separate collection is challenging. First, the airport waste composition was assessed, together with the efficiency of the manual sorting performed by passengers among the conventional bins: paper, plastic, glass & aluminium, and residual waste. Then, the environmental (via the life cycle assessment - LCA) and the economic performances of the current system were compared to those of a system in which the sorting is performed by the automatic bin. Three scenarios were evaluated: i) all waste from public areas, despite being separately collected, is sent to incineration with energy recovery, due to the inadequate separation quality (S0); ii) recyclable fractions are sent to recycling according to the actual level of impurities in the bags (S0R); iii) fractions are sorted by the automatic bin and sent to recycling (S1). According to the results, the current separate collection shows a 62 % classification accuracy. Focusing on LCA, S0 causes an additional burden of 12.4 mPt (milli points) per tonne of waste. By contrast, S0R shows a benefit (-26.4 mPt/t) and S1 allows for a further 33 % increase of benefits. Moreover, the cost analysis indicates potential savings of 24.3 €/t in S1, when compared to S0.

Trends and emerging research directions of sustainable aviation: A bibliometric analysis

This study aims to conduct a bibliometric analysis to determine trends and emerging research directions of sustainable aviation between 2001 and 2023. 726 studies indexed in the Web of Science were examined through VOSviewer software. Science mapping and performance analyses were implemented to demonstrate a systematic quantitative review and the characteristics of the research area. Moreover, by using co-occurrence of keywords, citation, bibliographic coupling, co-authorship, and co-citation analyses, the trends of the research area were revealed in detail. Findings indicated that the publications on sustainable aviation literature were mainly conducted between 2020 and 2023. Research areas of the publications were mainly on "engineering" and "energy fuels". In terms of number of the publications, "International Journal of Sustainable Aviation Fuel" was the most productive source and Heyne was the most productive author. Co-occurrence analysis demonstrated that "sustainable aviation fuel" was the most frequently used keyword. Furthermore, sustainable aviation research has shifted in focus toward more challenging and technology-oriented research over time. Citation analysis indicated that the most cited author was Heyne, the most cited study was Ma et al.'s study on "Aviation biofuel from renewable resources: routes, opportunities and challenges" and the most cited sources was "Energy". Among countries, the U.S.A was the most cited country and Chinese Academy of Sciences was the most cited organization. Bibliographic analysis showed that Heyne was the author with the highest connection strength. Co-authorship analysis demonstrated that Washington State University was the most collaborative organization. Finally, co-citation analysis of cited references indicated that fundamental subjects and related references were mainly sustainable aviation fuel, production of sustainable aviation fuel and its use in aviation studies. It is anticipated that results of this study would contribute to sustainable aviation research and ensure guidance and new perspectives for future research topics and directions on sustainable aviation.

A life cycle assessment of the laboratory-scale oxidative liquefaction as the chemical recycling method of the end-of-life wind turbine blades

According to the latest reports, estimated values of 50,000-66 000 t of end-of-life wind turbine blades (WTB) are expected to be decommissioned in Europe in 2025-2030, posing a significant threat from the environmental and waste management perspectives. This study aims to present the preliminary Life Cycle Assessment (LCA) with sensitivity and uncertainty analysis of the lab-scale oxidative liquefaction process of the WTB, as the original method to recover the high-quality glass fibers with simultaneous production of the secondary chemicals: phenols, ketones, acids, and fatty acids, from the oxidation of the epoxy resin from the polymer matrix. The LCA is based on the experimental results of the oxidative liquefaction process carried out on a laboratory scale using a Parr 500 ml batch reactor, at two different conditions sets for the functional unit (FU) of 1 kg of treated WTB. Each of the analyzed scenarios resulted in higher impact indicators compared to the landfilling. The highest quality fibers were obtained at 350 °C and 40 wt % H2O2 content resulted in 5.52 ± 1.20 kgCO2 eq Climate change impact and 97.8 ± 20.6 MJ of Resource use, fossil per kg of recycled WTB. The lowest quality fiber recovered in char, yet well separated from the matrix obtained at 250 °C and the lowest H2O2 content resulted in 0.0953 ± 0.487 kgCO2 eq Climate change impact and 8.84 ± 7.90 MJ of Resource use, fossil per kg of recycled WTB. The hot spot and sensitivity analysis indicated, that the oxidizer for the process - hydrogen peroxide, when acquired as a shelf product causes a significant burden on the whole process, with sensitivity ratios on the total impact indicators varying across the categories from 0.56 to 0.99. Substitution of H2O2 with theoretical 0-input oxidizer allowed to significantly lower environmental load of the recycling process, which in all of the analyzed scenarios presented environmental benefits compared to landfilling with recovery of the glass fiber and secondary chemicals.

Microcapsules of Poly(butylene adipate-co-terephthalate) (PBAT) Loaded with Aliphatic Isocyanates for Adhesive Applications

This work introduces the encapsulation of hexamethylene diisocyanate derivatives (HDI, TriHDI, and PHDI) with the biodegradable polymer poly(butylene adipate-co-terephthalate) (PBAT) through a solvent evaporation method. These microcapsules (MCs) were then employed in adhesive formulations for footwear. Moreover, MCs containing PHDI were produced in a closed vessel, demonstrating the potential for recovering and reusing organic solvents for the first time. The MCs were achieved with an isocyanate payload reaching up to 68 wt %, displaying a spherical shape, a core-shell structure, and thin walls without holes or cracks. The application of MCs as cross-linking agents for adhesives was evaluated following industry standards. The adhesives' strength surpassed the minimum requirement by a significant margin. Creep tests demonstrated that the formulation with MCs exhibits superior thermostability. Furthermore, the formulation with MCs-PHDI presented the best results reported to date for this type of system, as no displacement was observed in the bonded substrates. Environmental assessment indicates that adhesives with MCs have higher global warming potential (+16.2%) and energy consumption (+10.8%) than the standard commercial adhesives, but under alternative realistic scenarios, the differences can be insignificant. Therefore, adhesive formulations incorporating MCs promise to be on par with traditional adhesive systems regarding environmental impacts while providing benefits such as improved and safe handling of isocyanates and excellent bonding effectiveness.

Environmental impact of dietary patterns in 10 European countries; a cross-sectional analysis of nationally representative dietary surveys

BACKGROUND

Changing dietary patterns is essential to reducing the substantial environment impact of agriculture and food production systems. We performed a cross-country comparison of dietary patterns and their associated environmental impact in Europe, including by sociodemographic factors.

METHODS

We analyzed pooled cross-sectional dietary records collected during 2010-18 from 10 European countries using the European Food Safety Authority (EFSA) Comprehensive European Food Database (16 508 adults; aged 18-79 years). Each food consumed was mapped to the corresponding environmental impact data using the SHARP Indicators Database, which provides greenhouse gas emission (GHGE) and land use (LU) values of approximately 900 foods. Total diet-associated environmental impact was calculated for each person and averaged across multiple days. Multivariable linear regression models were used to compare diet-associated GHGE and LU between population subgroups (gender, age, education and diet type) with country-level fixed effects.

RESULTS

The mean dietary GHGE and LU per capita ranged from 4.0 kgCO2/day and 5.0 m2*year/day in Spain to 6.5 kgCO2eq/day and 8.2 m2*year/day in France. Diet-related GHGE and LU (per kg/food) were lower among females (2.6 kgCO2eq/day, B = -0.08, P < 0.01; 3.2 m2*year/day, B = -0.11, P < 0.01), older population aged 66-79 (2.6 kgCO2eq/day, B = -0.03, P < 0.01; 3.4 m2*year/day, B = -0.4, P < 0.01), people following vegetarian diets (1.7 kgCO2eq/day, B = -0.07, P < 0.01; 2.0 m2*year/day, B = -0.07, P < 0.01), and higher among individuals with secondary education (2.7 kgCO2eq/day, B = 0.05, P < 0.01; 3.6 m2*year/day, B = -0.05, P < 0.01).

CONCLUSIONS

Environmental footprints vary substantially across countries, dietary patterns and between different sociodemographic groups in Europe. These findings are crucial for the development of country-specific food policies aimed at promoting environmentally sustainable diets.

Evaluating the environmental impacts of smart vineyards through the Life Cycle Assessment

This study aimed to assess the environmental effectiveness of vineyards utilising on-site weather stations integrated with a decision support system (DSS), and to identify the critical hotspots in smart farms that have already obtained integrated or organic certification. For this purpose, Life Cycle Assessment (LCA) methodology was applied. The research comprised three smart farms employing on-site weather stations and a traditional farm without advanced technologies, which served as a benchmark. The analysis revealed variations in environmental footprints driven by differences in farm management practices and soil characteristics. The results highlighted that smart farms, in compliance with integrated or organic certifications, focus on reducing inputs such as agrochemicals or water consumption. However, these reductions could shift the environmental burden to other impacts, such as those related to machinery use, which remained the most critical aspect across all vineyards considered. In some smart farms, critical issues involve other aspects, such as irrigation and fertilisation. The lack of awareness about the potential environmental impacts of the adopted technical options could make smart farms more impactful than traditional farms. Interestingly, this study found that solely implementing advanced technologies could fall short of achieving ecological objectives. This study emphasises the significance of utilising LCA as a valuable tool to support farmers in making informed decisions while adopting technological strategies to achieve environmentally sustainable goals.

Life cycle assessment of secondary use and physical recycling of lithium-ion batteries retired from electric vehicles in China

With the rapid development of the global new energy vehicle industry, how to minimize the environmental impact of the recovery has become a common concern and urgent concern. China is a major production and consumption market for electric vehicles, there are no specific and extensive resource and environmental assessment system for batteries. In this paper, the retired Electric vehicles lithium-ion batteries (LIBs) was the research object, and a specific analysis of the recycling treatment and gradual use stages of power batteries were based on life cycle assessment. Different battery assessment scenarios were established according to the development of battery recycling in China. The results showed that the secondary use has the optimal performance compared to the full-component physical, pyrometallurgical and hydrometallurgy recycling. The results showed that direct recycling has a GWP of 0.037 kg-CO2 eq·kg LIB-1, which is lower than others. Secondary use of LIB accounts for the most emission reductions with Global warming (GWP) as 12.134 kg-CO2 eq·kg LIB-1. The secondary use has the greatest impact on the assessment results, especially in dynamic scenarios. Through a comprehensive comparison of different recycling technologies, the secondary use, increasing the recycling rate, reducing resource, energy consumption and pollution emissions.

Dynamic life cycle assessment of commercial and household food waste: A critical global review of emerging techniques

DLCA has been applied to several food waste streams, however, to date no critical assessment of its strengths, weaknesses, opportunities, and threats (SWOT) is available in the scientific literature. Accordingly, the present review aims to provide a comprehensive overview of the available literature on DLCA and its application to Household and Commercial Food Waste (HCFW) by providing critical assessment and perspectives for future research. The Population, Intervention, Comparison, and Outcome (PICO) framework for literature review was employed, with just 12 relevant studies identified between 1999 and 2022, highlighting a dearth of research on DLCA of food waste and the need for further research. Identified studies exhibit significant variations with respect to DLCA methodology, boundary settings, and data quality and reporting, with more attention typically given to combining conventional LCA with dynamic characterization models, thus making it difficult to draw conclusive findings or identify consistent trends. Additionally, most identified studies employed DLCA for a specific case study and comparison with traditional LCA outcomes was typically ignored; just one study presented the projected impact from both LCA and DLCA for the entire life cycle of a product. Employed functional/reference units ranged from specific quantities such as 1 kg of refined crystals or syrup, 1 g L-1 Sophorolipid solution, and 1 kg of dry food with packaging material, to broader indicators like 1 kg of biofuel or 1 MJ of primary energy. Monte Carlo simulation was the most frequently employed method for uncertainty analyses within identified studies. Sensitivity analyses were conducted in just 4 studies, but it was not always clearly reported. While DLCA is undoubtedly a more realistic approach to impact assessment, and thus likely more accurate, a need exists for increasingly standardized and regulated versions of DLCA for global and multi-criteria practices.

Designing a sustainable reverse logistics network for used cell phones based on offline and online trading systems

Unsustainable production and consumption are driving a significant increase in global electronic waste, posing substantial environmental and human health risks. Even in more developed nations, there is the challenge of low collection rates. In response, we integrate offline and online trading systems and design a material efficiency strategy for used cell phones. We propose a new multi-objective optimization framework to maximize profit, carbon emissions reduction, and circularity in the process of recycling and treatment. Considering multi-period, multi-product, multi-echelon features, as well as price sensitive demand, incentives, and qualities, we established a new multi-objective mixed-integer nonlinear programming optimization model. An enhanced, Fast, Non-Dominated Solution Sorting Genetic Algorithm (ASDNSGA-II) is developed for the solution. We used operational data from a leading Chinese Internet platform to validate the proposed optimization framework. The results demonstrate that the reverse logistics network designed achieves a win-win situation regarding profit and carbon emission reduction. This significantly boosts confidence and motivation for engaging in recycling efforts. Online recycling shows robust profitability and carbon reduction capabilities. An effective coordination mechanism for pricing in both online and offline channels should be established, retaining offline methods while gradually transitioning towards online methods. To increase the collection rate, it is essential to jointly implement a transitional strategy, including recycling incentives and subsidy policies. Additionally, elevating customer environmental awareness should be viewed as a long-term strategy, mitigating the cost of increasing collection rates during the market maturity stage (high collection rates).

Towards a sustainable environment and carbon neutrality: Optimal sizing of standalone, green, reliable, and affordable water-power cogeneration systems

Today, the limited sources of freshwater supply are a significant concern. Exploiting alternative sources, especially seawater, has been the focus, but purifying it is energy-intensive. Integrating desalination with renewable energy is a proposed solution, but it comes with high costs and environmental risks during construction. Hence, this study presents a framework to enhance the modeling, optimization, and evaluation of green water-power cogeneration systems to achieve the sustainability goals of cities and societies. An improved division algorithm (DA) determines the optimal component sizes based on criteria like minimal energy demand, reduced environmental and resource damage, low total life cycle cost (TLCC), and high reliability. Optimization considers varying loss of power supply probability (LPSP) levels (0 %, 2 %, 5 %, and 10 %). The environmental assessment utilizes a life cycle assessment (LCA) approach with IMPACT 2002+ and cumulative energy demand (CED) calculations. The study models the green cogeneration systems based on weather conditions, water demand, and power requirements of Al Lulu Island, Abu Dhabi, UAE. The system comprises photovoltaic panels, wind turbines, tidal generators, and backup systems (fuel cells). Results reveal that TLCC ranges from $186,263 to $486,876 for the highest LPSP. The solar-tidal-based configuration offers the lowest TLCC ($186,263) while substituting solar with wind energy increases TLCC by 160 %. The wind-tidal-based configuration has the lowest specific environmental impact (1020 mPt/yr) and cumulative energy demand (39.06 GJ/yr) for the highest LPSP. In contrast, the solar-tidal-wind-based configuration inflicts the most damage, with 62.63 GJ/yr and 1794 mPt/yr for the highest LPSP. The finding indicates that the DA is faster (100 iterations) than the genetic algorithm (1000 iterations), particle swarm optimization (400 iterations), and artificial bee swarm optimization (300 iterations). The study underscores the solar-tidal-based configuration as the optimal choice across multiple criteria, offering a promising solution for freshwater supply and environmental sustainability on Al Lulu Island.

Life cycle analysis of common landfill final cover systems focusing on carbon neutrality

Carbon emissions from landfill construction and management have become a global concern. Life cycle analysis (LCA) has been widely used to assess the environmental impacts of engineered infrastructures over their lifetimes. LCA has also been applied to landfill leachate and gas management, but rarely to landfill final cover systems. This paper reports the results of an LCA of the following landfill final cover systems: compacted clay cover, geomembrane cover, cover with capillary effects (CCBE), dual capillary barrier cover, three-layer landfill cover system using natural soils, three-layer cover using recycled concrete aggregate (RCA) and biochar-amended three-layer landfill cover system using RCA. The LCA assessment of landfill cover considers the cost, carbon emissions and carbon sequestration during the production, construction and operation phases. The effects of landfill cover on global warming, freshwater eutrophication, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity and fossil resource scarcity are also evaluated. In addition, the sensitivities of cost and carbon emission to the use of electric-powered machines and transportation distance are analysed. It is revealed that the three-layer cover system using RCA and biochar has the lowest unit cost and carbon emission of all of the covers, up to 88 % and 66 % lower, respectively, than those of the other six covers. In addition, this cover system has the highest carbon sequestration rate, with a value of 47.9 kg CO2/(y·m2), four times higher than that of the compacted clay cover. Finally, this sustainable cover mitigates global warming and reduces adverse environmental impacts by up to 82 %. Therefore, the biochar amended three-layer cover system using RCA without geomembrane offers the greatest economic benefits, performs effectively in terms of the pursuit of carbon neutrality and promotes sustainable development.

Waste LCA and the future

Life cycle assessment (LCA) models quantifying the environmental aspects of waste management have become an integral part of waste management decision-making over the last two decades and have provided ample knowledge on both environmental benefits and drawbacks in the way we handle waste. Waste management and LCA modelling of waste management systems will soon be challenged by profound changes necessary in our societies and sectors to meet sustainable development goals. Foreseen changes in energy, material, and nutrient provision will directly and indirectly affect waste management in terms of its operation and goals. This study reflects on anticipated changes in society and industrial sectors and how these changes may affect waste management and LCA modelling of waste management systems in terms of waste input, the modelling of technologies and systems and exchanges of energy, materials, and nutrients, as well as how it may affect impact assessment and the interpretation of results. The study provides practical recommendations for LCA modelling of future waste management systems, which will hopefully lead to robust assessments that can support decision-making in an evolving society subject to great changes.

Modular life cycle assessment approach: Environmental impact of rainwater harvesting systems in urban water systems

The environmental assessment of urban water systems through life cycle analysis can be facilitated by using a modular approach. This study aimed to use such an approach to assess the impact of implementing rainwater harvesting systems in buildings in the urban environment during their lifespan, from manufacture to disposal. For this purpose, urban systems were divided into components (water treatment plant, potable water distribution, consumer water use, wastewater collection and wastewater treatment plant). The impacts were quantified using the ReCiPe 2016 H impact assessment method, which considers eighteen impact categories. A case study was carried out in the Belém river basin in central Curitiba, southern Brazil, to validate the method. The results showed a reduction of environmental impacts of up to 23.0 % on water treatment plants, up to 19.0 % on potable water distribution and up to 11.3 % on wastewater treatment plants with the implementation of rainwater harvesting systems. The consumer component was the most significant contributor in eight and seven impact categories in the scenarios with and without rainwater harvesting, respectively. Despite the increased infrastructure materials, the results showed potential for environmental impact reduction with rainwater harvesting, mainly in urban water systems' operation process (energy and chemicals consumption). By analysing the total impacts, implementing rainwater harvesting reduced the impacts in eleven out of eighteen impact categories analysed (up to 11.0 % reduction). The principal reductions occurred in ozone depletion, ionising radiation and water use. Finally, the modular life cycle assessment approach proved to be a comprehensive analysis, which can aid in the analysis and decision-making for different scenarios.

From plastic waste to potential wealth: Upcycling technologies, process synthesis, assessment and optimization

Global plastics production has doubled since the beginning of 21st century. Efficient technology is called for plastics waste valorization. The current review provides an overview of the main waste plastic chemical upcycling technologies to produce value-added products. Various technologies including gasification and pyrolysis are under reviewed. However, several review literatures have paid attention to the details and experimental progress in these chemical upcycling techniques. In this review, we attempt to conclude the progress in a multi-scale systems-by-systems perspective. After a brief overview of the current state-of-the-art chemical upcycling techniques, larger-scale process synthesis, assessment, and optimization methodologies to address the sustainability and environmental issues are summarized. Techno-economic analysis and life cycle assessment are selected as two powerful tools for process assessment. Three particular application scenarios of optimization methodologies including experimental design, process synthesis and supply chain management are consequently introduced. Very little work on review articles have summarized the plastic waste-to-wealth process in the systems engineering perspective. Review results show that (1) gasification and pyrolysis offer promising avenues for the conversion of plastic waste into valuable products. These technologies can be integrated with other subsystems to enhance the economic and environmental performance of the overall system. (2) Response surface methodology is commonly used in experimental design and parameter optimization. It allows researchers to systematically investigate the effects of various parameters and optimize process conditions to maximize desired outputs. (3) Superstructure optimization frameworks are valuable tools for process synthesis and pathway selection in plastic waste conversion. However, the potential superstructure is pre-defined. (4) Green supply chain and multi-objective supply chain frameworks can be applied to the design of plastic waste recycling networks, taking into account both economic and environmental considerations.

Environmental problem shifting from climate change mitigation: A mapping review

Climate change mitigation will trigger major changes in human activity, energy systems, and material use, potentially shifting pressure from climate change to other environmental problems. We provide a comprehensive overview of such "environmental problem shifting" (EPS). While there is considerable research on this issue, studies are scattered across research fields and use a wide range of terms with blurred conceptual boundaries, such as trade-off, side effect, and spillover. We identify 506 relevant studies on EPS of which 311 are empirical, 47 are conceptual-theoretical, and 148 are synthetic studies or reviews of a particular mitigation option. A systematic mapping of the empirical studies reveals 128 distinct shifts from 22 categories of mitigation options to 10 environmental impacts. A comparison with the recent IPCC report indicates that EPS literature does not cover all mitigation options. Moreover, some studies systematically overestimate EPS by not accounting for the environmental benefits of reduced climate change. We propose to conceptually clarify the different ways of estimating EPS by distinguishing between gross, net, and relative shifting. Finally, the ubiquity of EPS calls for policy design which ensures climate change mitigation that minimizes unsustainability across multiple environmental dimensions. To achieve this, policymakers can regulate mitigation options-for example, in their choice of technology or location-and implement complementary environmental policies.

Waste-to-energy and waste-to-hydrogen with CCS: Methodological assessment of pathways to carbon-negative waste treatment from an LCA perspective

A growing global population and rising living standards are producing ever greater quantities of waste, while at the same time driving ever-larger demand for energy, especially electricity, or new emerging markets, such as hydrogen in more industrialised countries. A key solution to these challenges of waste disposal, rising energy and hydrogen demand is BECCS (Bioenergy with Carbon Capture and Storage); the generation of bioenergy - in the form of electricity (WtE) or hydrogen (WtH2), as well as heat - from the thermochemical processing of waste. The addition of carbon capture and storage (CCS) to WtE or WtH2 has the potential to make waste a zero or even negative emissions energy source, thus contributing to the removal of greenhouse gases from the atmosphere. This work undertakes a pre-screening of different BECCS configurations based on state of the art technologies and then performed an assessment of representative cases in UK for WtE and WtH2, necessary to understand if novel waste thermal treatment processes may become potential alternatives or improvements to current WtE plants when retrofitted with CCS. A systematic and comprehensive examination of different key Life Cycle Assessment methodological aspects reveals the importance of the functional unit and allocation approach in determining the preferred pathway in a specific context.

Evaluating the Ecological Footprint of Landfills: A Framework and Case Study of Fargo, North Dakota

There is growing interest in better understanding the environmental impacts of landfills and optimizing their operation. Accordingly, we developed a holistic framework to calculate a landfill's Ecological Footprint (EF) and applied that to the Fargo, North Dakota, landfill. Parallelly, the carbon footprint and biocapacity of the landfill were calculated. We calculated the EF for six scenarios (i.e., cropland, grazing land, marine land, inland fishing ground, forest land, and built land as land types) and six operational strategies typical for landfills. Operational strategies were selected based on the variations of landfill equipment, the gas collection system, efficiency, the occurrence of fugitive emissions, and flaring. The annual EF values range from 124 to 213,717 global hectares depending on land type and operational strategy. Carbon footprints constituted 28.01-99.98% of total EF, mainly driven by fugitive emissions and landfill equipment. For example, each percent increase in Fargo landfill's fugitive emissions caused the carbon footprint to rise by 2130 global hectares (4460 tons CO2e). While the landfill has biocapacity as grazing grass in open spaces, it remains unused/inaccessible. By leveraging the EF framework for landfills, operators can identify the primary elements contributing to a landfill's environmental impact, thereby minimizing it.

Life Cycle Assessment of a large commercial kelp farm in Shandong, China

The environmental benefits of seaweed cultivation have gained a lot of attention, both in policy strategies and by private companies. Sustainability evaluations of seaweed farming have however focused on a very small part of global production of seaweed - on European cultivations at research and pilot-scales although Asia stands for 99 % of global production with China alone producing 60 %. In this study, we use Life Cycle Assessment (LCA) to evaluate the environmental performance of a 400-hectare Chinese kelp farm with a yearly harvest of 60,000 tons. Primary data from the farm was used to assess impacts up until harvest for the functional unit of 1 ton of fresh-weight kelp. Included in the LCA were impact on climate change, acidification terrestrial and marine eutrophication, and use of land water and energy. In addition, we calculated nutrient uptake. Further, we extracted inventory data of four published LCA studies of farmed kelp and recalculated environmental impacts, applying the same background data and method choices with the aim to compare the effects of scale and cultivation system. The results of the hotspot analysis showed that the plastic ropes and buoys dominated impacts on climate change, freshwater and marine eutrophication, and energy consumption. Consequently, the most effective improvement action was recycling after use. The yearly harvest of the Chinese farm was 1000-4000 times larger than previously evaluated farms compared. Results suggest that streamlined and mature production in the large-scale Chinese kelp farm led to lower electricity and fuel consumption compared to small-scale production, thus placing the Chinese farm with a climate impact of 57.5 kg CO2 eq. per ton fresh-weight kelp on the lower end when comparing the carbon footprint. There was a large variation in carbon footprints, which implies that the kelp cultivation sector has considerable room for optimization.

Nutritional, environmental and economic impacts of ultra-processed food consumption in Australia

OBJECTIVE

To quantify the full life cycle impacts of ultra-processed foods (UPF) for key environmental, economic and nutritional indicators to identify trade-offs between UPF contribution to broad-scope sustainability.

DESIGN

Using 24-h dietary recalls along with an input-output database for the Australian economy, dietary environmental and economic impacts were quantified in this national representative cross-sectional analysis. Food items were classified into non-UPF and UPF using the NOVA system, and dietary energy contribution from non-UPF and UPF fractions in diets was estimated. Thereafter, associations between nutritional, environmental and economic impacts of non-UPF and UPF fractions of diets were examined using a multi-dimensional nutritional geometry representation.

SETTING

National Nutrition and Physical Activity Survey 2011-2012 of Australia.

PARTICIPANTS

Respondents (n 5344) aged > 18 years with 1 d of 24-h dietary recall data excluding respondents with missing values and outlier data points and under reporters.

RESULTS

Australian diets rich in UPF were associated with reduced nutritional quality, high greenhouse gas emissions, energy use, and increased employment and income associated with the food supply chains. The environmental and economic impacts associated with the UPF portion of diets become more distinct when the diets are standardised to average protein recommendation.

CONCLUSION

Increased consumption of UPF has socio-economic benefits, but this comes with adverse effects on the environment and public health. Consideration of such trade-offs is important in identifying policy and other mechanisms regarding UPF for establishing healthy and sustainable food systems.

Production of chemicals and utilities in-house improves the environmental sustainability of phytoplankton-based biorefinery

Life cycle assessment was used to evaluate the environmental impacts of phytoplanktonic biofuels as possible sustainable alternatives to fossil fuels. Three scenarios were examined for converting planktonic biomass into higher-value commodities and energy streams using the alga Scenedesmus sp. and the cyanobacterium Arthrospira sp. as the species of interest. The first scenario (Sc-1) involved the production of biodiesel and glycerol from the planktonic biomass. In the second scenario (Sc-2), biodiesel and glycerol were generated from the planktonic biomass, and biogas was produced from the residual biomass. The process also involved using a catalyst derived from snail shells for biodiesel production. The third scenario (Sc-3) was similar to Sc-2 but converted CO2 from the biogas upgrading to methanol, which was then used in synthesizing biodiesel. The results indicated that Sc-2 and Sc-3 had a reduced potential (up to 60 % less) for damaging human health compared to Sc-1. Sc-2 and Sc-3 had up to 61 % less environmental impact than Sc-1. Sc-2 and Sc-3 reduced the total cumulative exergy demand by up to 44 % compared to Sc-1. In conclusion, producing chemicals and utilities within the biorefinery could significantly improve environmental sustainability, reduce waste, and diversify revenue streams.

Circular economy and its implementation in cement industry: A case point in Pakistan

The cement industry contributes substantially to world emissions. Sustainable and circular practices are adopted globally to mitigate such emissions. Developing countries like Pakistan lack adaptation to circular and sustainable practices. The study proposes an alternative mix of coal and crop residues that can be used for cement production. The study aims to find the best mixtures of coal with crop residue for combustion purposes in cement industries. The Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) are implemented for the environmental and economic viability of the proposed material mixtures. Moreover, the study seeks to explore risks associated with the implementation of circular practices in the cement industry of a developing country. The study adopts Modified Safety Improvement Risk Assessment (SIRA) for assessing the risks. The results suggest that the partial replacement of coal with bagasse is the most viable mixture with lower environmental emissions and is economically feasible among other alternate mixtures. In terms of risk assessment, there is a lack of governmental support for adopting circular economy (CE) practices and profit uncertainties of these CE practices.

Identifying and prioritizing sustainability indicators for China's assessing demolition waste management using modified Delphi-analytic hierarchy process method

Addressing the sustainability issues arising from construction and demolition waste management (DWM) has gained little traction due to the lack of incentives, stringent regulations, and systematic guidance. This study aims to empower systematic decision-making concerning DWM alternative selection by developing a sustainability assessment framework by coupling a modified Delphi method with the multicriteria decision analysis technique. First, the study identifies a comprehensive inventory of indicators across three dimensions of sustainability in the context of DWM. Next, the study combines a modified Delphi method with the analytic hierarchy process to validate and prioritize the selected sustainability indicators. For the first time, insights regarding the DWM sustainability indicators from China's construction industry practitioners' perspectives are elicited using a mixed method comprising online semistructured interviews and two rounds of questionnaire surveys. Experts participating in the research are mostly based in Guangzhou and Shenzhen, where local governments exhaust all efforts in promoting carbon-neutral and sustainable development. The findings reveal that eight sustainability indicators were regarded as the determinants for the sustainability performance of DWM, with the global warming potential (32%), energy efficiency (16.1%) and land use (13.5%) receiving the highest preference scores (weights) based on the experts' judgment. Notably, the economic factors like the total cost (6.54%) appeared not highly prioritized by the local experts as typically did in the previous studies from developing countries.

Achieving decent living standards in emerging economies challenges national mitigation goals for CO2 emissions

Emerging economies, low- and middle-income countries experiencing rapid population and GDP growth, face the challenge of improving their living standards while stabilizing CO2 emissions to meet net-zero goals. In this study, we quantify the CO2 emissions required for achieving decent living standards (DLS) in emerging economies. The results show that, compared to other regions, achieving DLS in emerging Asian and African economies will result in more additional CO2 emissions, particularly in the DLS indicators of Mobility and Electricity. Achievement of DLS in emerging economies will result in 8.6 Gt of additional CO2 emissions, which should not jeopardize global climate targets. However, a concerning trend arises as more than half of the emerging economies (62 out of 121) will face substantial challenges in aligning their expected emission growth for achieving DLS with their national emission mitigation targets.

Microbial Desalination Cell for Sustainable Water Treatment: A Critical Review

In view of increasing threats arising from the shortage of fresh water, there is an urgent need to propose sustainable technologies for the exploitation of unconventional water sources. As a derivative of microbial fuel cells (MFCs), microbial desalination cell (MDC) has the potential of desalinating saline/brackish water while simultaneously generating electricity, as well as treating wastewater. Therefore, it is worth investigating its practicability as a potential sustainable desalination technology. This review article first introduces the fundamentals and annual trends of MDCs. The desalination of diverse types of solutions using MDCs along with their life cycle impact assessment (LCIA)  and economic analysis is studied later. Finally, limitations and areas for improvement, prospects, and potential applications of this technology are discussed. Due to the great advantages of MDCs, improving their design, building materials, efficiency, and throughput will offer them as a significant alternative to the current desalination technologies.

Assessment of building materials in the construction sector: A case study using life cycle assessment approach to achieve the circular economy

The construction sector plays a significant role in contributing to greenhouse gas (GHG) emissions, necessitating effective and practical solutions. This study addresses the underutilization of Life Cycle Assessment (LCA) in the construction sector and demonstrates its benefits as a decision-making tool for mitigating embodied carbon. The research focuses on a G+2 building in Dubai, UAE, conducting LCA during the construction phases to assess embodied carbon levels. Results indicate that the careful selection of construction materials and involvement of LCA at the early stages of construction resulted in a 26 % reduction in the building's embodied carbon. The study recognizes the limitations of LCA but emphasizes its value and recommends future research to enhance its coverage of sustainability aspects. The findings highlight the construction sector's potential to overcome anthropogenic challenges through green solutions. Policymakers' support is crucial for implementing strategies that reduce the construction industry's carbon footprint and embrace a circular economy. The study contributes to the literature by bridging the gap in understanding the application of LCA in construction decision-making. It emphasizes the importance of transitioning to sustainable practices and circularity in the construction sector. By using LCA as a tool, construction professionals can make informed choices to reduce embodied carbon. This study underscores the urgency for adopting greener practices in the construction sector, leading to a more sustainable and low-carbon future.

Design of a syringe extension device (Chloe SED®) for low-resource settings in sub-Saharan Africa: a circular economy approach

Underfunded healthcare infrastructures in low-resource settings in sub-Saharan Africa have resulted in a lack of medical devices crucial to provide healthcare for all. A representative example of this scenario is medical devices to administer paracervical blocks during gynaecological procedures. Devices needed for this procedure are usually unavailable or expensive. Without these devices, providing paracervical blocks for women in need is impossible resulting in compromising the quality of care for women requiring gynaecological procedures such as loop electrosurgical excision, treatment of miscarriage, or incomplete abortion. In that perspective, interventions that can be integrated into the healthcare system in low-resource settings to provide women needing paracervical blocks remain urgent. Based on a context-specific approach while leveraging circular economy design principles, this research catalogues the development of a new medical device called Chloe SED® that can be used to support the provision of paracervical blocks. Chloe SED®, priced at US$ 1.5 per device when produced in polypropylene, US$ 10 in polyetheretherketone, and US$ 15 in aluminium, is attached to any 10-cc syringe in low-resource settings to provide paracervical blocks. The device is designed for durability, repairability, maintainability, upgradeability, and recyclability to address environmental sustainability issues in the healthcare domain. Achieving the design of Chloe SED® from a context-specific and circular economy approach revealed correlations between the material choice to manufacture the device, the device's initial cost, product durability and reuse cycle, reprocessing method and cost, and environmental impact. These correlations can be seen as interconnected conflicting or divergent trade-offs that need to be continually assessed to deliver a medical device that provides healthcare for all with limited environmental impact. The study findings are intended to be seen as efforts to make available medical devices to support women's access to reproductive health services.

Unveiling Sustainable Potential: A Life Cycle Assessment of Plant-Fiber Composite Microcellular Foam Molded Automotive Components

The development and utilization of new plant-fiber composite materials and microcellular foam molding processes for the manufacturing of automotive components are effective approaches when achieving the lightweight, low-carbon, and sustainable development of automobiles. However, current research in this field has mainly focused on component performance development and functional exploration, with a limited assessment of environmental performance, which fails to meet the requirements of the current green and sustainable development agenda. In this study, based on a life cycle assessment, the resource, and environmental impacts of plant-fiber composite material automotive components and microcellular foam molding processes were investigated. Furthermore, a combined approach to digital twinning and life cycle evaluation was proposed to conduct resource and environmental assessments and analysis. The research results indicate that under current technological conditions, resource and environmental issues associated with plant-fiber composite material automotive components are significantly higher than those of traditional material components, mainly due to differences in their early-stage processes and the consumption of electrical energy and chemical raw materials. It is noteworthy that electricity consumption is the largest influencing factor that causes environmental issues throughout the life cycle, especially accounting for more than 42% of indicators such as ozone depletion, fossil resource consumption, and carbon dioxide emissions. Additionally, the microcellular foam molding process can effectively reduce the environmental impact of products by approximately 15% and exhibits better overall environmental performance compared to chemical foaming. In future development, optimizing the forming process of plant-fiber composite materials, increasing the proportion of clean energy use, and promoting the adoption of microcellular foam injection molding processes could be crucial for the green and sustainable development of automotive components.

The thermodynamic and life-cycle assessments of a novel charging station for electric vehicles in dynamic and steady-state conditions

The current study performs the thermodynamic and life-cycle assessments (LCA) of a novel charging station in two system designs. The goal is to design an efficient charging station for electric vehicles with high efficiencies and low environmental impacts using Solid Oxide Fuel Cell (SOFC) technology. SOFC is considered a sustainable and environmentally friendly technology to generate electricity compared to combustion engines. To ameliorate the performance, the exhaust heat of the SOFC stacks will be recovered for hydrogen production in an electrolyzer. The system uses four SOFCs to charge the electric vehicles while the output heat is recovered by an Organic Rankine Cycle (ORC) to generate further electricity for hydrogen production in an electrolyzer. In the first design, it is assumed that the SOFC stacks will work full-load during the 24 h of the day, while the second design considers full-load operation for 16 h and part-load (30%) operation for 8 h. The second design of the system analyzes the possibility of integrating a [Formula: see text] lithium-ion battery stores the excessed electricity once the power load is low and acts as a backup in high power demands. Results of the thermodynamic analysis calculated the overall efficiencies of 60.84% and 60.67% for the energy and exergy, respectively, with the corresponding power and hydrogen production of 284.27 kWh and 0.17 g/s. It was observed that higher current density would increase the output of SOFC while reducing the overall energy and exergy efficiencies. In dynamic operation, the use of the batteries can well balance the change of the power loads and improve the dynamic response of the system to the simultaneous changes in the power demand. LCA results also showed that the 284.27kWh system leads to global warming (kg [Formula: see text] eq) of 5.17E+05, 4.47E+05, and 5.17E+05 using Solid Oxide Electrolyzer (SOE), Proton Exchange Membrane Electrolyzer (PEME), and Alkaline Electrolyzer (ALE), respectively. In this regard, the usage of PEME has the lowest impact on the environment in comparison to SOEC, and ALE. A comparison between the environmental impacts of different ORC's working fluids also suggested against the usage of R227ea while R152a showed promising results to be used in the system. The size and weight study also revealed that the battery benefits from the lowest volume and weight in comparison to the other components. Among the considered components in this study, the SOFC unit and the PEME have by far the highest volume.

Production in peatlands: Comparing ecosystem services of different land use options following conventional farming

Majority of Dutch peatlands are drained and used intensively as grasslands for dairy farming. This delivers high productivity but causes severe damage to ecosystem services supply. Peatland rewetting is the best way to reverse the damage, but high water levels do not fit with intensive dairy production. Paludiculture, defined as crop production under wet conditions, provides viable land use alternatives. However, performance of paludiculture is rarely compared to drainage-based agriculture. Here, we compared the performances of six land use options on peatland following a gradient of low, medium, and high water levels, including conventional and organic drainage-based dairy farming, low-input grasslands for grazing and mowing, and high-input paludiculture with reed and Sphagnum cultivation. For each land use option, we conducted environmental system analysis on model farm system defined by a literature based inventory analysis. The analysis used five ecosystem services as indicators of environmental impacts with a functional unit of 1-ha peat soil. Ecosystem services included biomass provisioning, climate, water, and nutrient regulation, and maintenance of habitat. Results showed that drainage-based dairy farming systems support high provisioning services but low regulation and maintenance services. Organic farming provides higher climate and nutrient regulation services than its conventional counterpart, but limited overall improvement due to the persistent drainage. Low-intensity grassland and paludiculture systems have high regulation and maintenance services value, but do not supply biomass provisioning comparable to the drainage-based systems. Without capitalizing the co-benefits of regulation and maintenance services, and accounting for the societal costs from ecosystem disservices including greenhouse gas emission and nitrogen pollution, it is not likely that the farmers will be incentivized to change the current farming system towards the wetter alternatives. Sustainable use of peatlands urges fundamental changes in land and water management along with the financial and policy support required.

Vineyard Pruning Extracts as Natural Antioxidants for Biodiesel Stability: Experimental Tests and Preliminary Life Cycle Assessment

The control of the oxidative stability of biodiesel and blends of biodiesel with diesel is one of the major concerns of the biofuel industry. The oxidative degradation of biodiesel can be accelerated by several factors, and this is most critical in the so-called second generation biodiesel, which is produced from low-cost raw materials with lower environmental impacts. The addition of antioxidants is imperative to ensure the oxidative stability of biodiesel, and these are considered products of high commercial value. The antioxidants currently available on the market are from synthetic origin, so the existence/availability of alternative antioxidants of natural origin (less dependent on fossil sources) at a competitive price presents itself as a strong business opportunity. This work describes and characterizes a sustainable alternative to synthetic antioxidants used in the biodiesel market developed from extracts of vineyard pruning waste (VPW), which are naturally rich in phenolic compounds with antioxidant properties. A hydrothermal extraction process was applied as a more efficient and sustainable technology than the conventional one with the potential of the extracts as antioxidant additives in biodiesel evaluated in Rancitech equipment. The VPW extract showed comparable antioxidant activity as the commercial antioxidant butylated hydroxytoluene (BHT) typically used in biodiesel. The stability of the biodiesel is dependent from the amount of the extract added. Further, for the first time, the assessment of the environmental impacts of using natural extracts to control the oxidative stability of biodiesel in the production process is also discussed as a key factor of the process environmental sustainability.

Sustainable management of food waste; pre-treatment strategies, techno-economic assessment, bibliometric analysis, and potential utilizations: A systematic review

Food waste (FW) contains many nutritional components such as proteins, lipids, fats, polysaccharides, carbohydrates, and metal ions, which can be reused in some processes to produce value-added products. Furthermore, FW can be converted into biogas, biohydrogen, and biodiesel, and this type of green energy can be used as an alternative to nonrenewable fuel and reduce reliance on fossil fuel sources. It has been demonstrated in many reports that at the laboratory scale production of biochemicals using FW is as good as pure carbon sources. The goal of this paper is to review approaches used globally to promote turning FW into useable products and green energy. In this context, the present review article highlights deeply in a transdisciplinary manner the sources, types, impacts, characteristics, pre-treatment strategies, and potential management of FW into value-added products. We find that FW could be upcycled into different valuable products such as eco-friendly green fuels, organic acids, bioplastics, enzymes, fertilizers, char, and single-cell protein, after the suitable pre-treatment method. The results confirmed the technical feasibility of all the reviewed transformation processes of FW. Furthermore, life cycle and techno-economic assessment studies regarding the socio-economic, environmental, and engineering aspects of FW management are discussed. The reviewed articles showed that energy recovery from FW in various forms is economically feasible.

Life cycle assessment of the hydrothermal carbonization process applied to the wet fraction mechanically separated from municipal mixed waste

The under-sieve fraction (USF), obtained as one of the output streams from the mechanical pretreatment of mixed municipal solid waste, is usually aerobically biologically stabilized before being landfilled. For its characteristics (i.e., moisture and organic content), the USF can be alternatively processed by hydrothermal carbonization (HTC), producing hydrochar to be used for energy production. Based on previous results obtained from laboratory HTC tests of the USF, this work is aimed at evaluating the sustainability of the proposed process from an environmental point of view by applying the Life Cycle Assessment. Various combinations of process parameters (temperature, time, and dry solid-to-water ratios) and two different utilization pathways for hydrochar (the whole amount produced in external lignite power plants or part of it used internally) are compared. The results indicate that environmental performances are mainly connected with process energy consumption: in general, the cases operating at the lowest dilution ratio and the highest temperature provide improved environmental indicators. Co-combusting all the produced hydrochar in external power plants provides better environmental performances than feeding a portion of it to the HTC itself: the avoided effects by displacing lignite are higher than the additional burdens from natural gas use. Then, alternative process water treatments are compared, showing that the burdens added by the process water treatments do not offset the benefits generated by the main HTC process for the major part of the considered environmental indicators. Finally, the proposed process indicates better environmental performances when compared to the conventional method of treating the USF, based on aerobic biostabilization and landfilling.

Environmental sustainability assessment of a polyester T-shirt - Comparison of circularity strategies

The considerable environmental burden of textiles is currently globally recognized. This burden can be mitigated by applying circular economy (CE) strategies to the commonly linear, short garment life cycles that end with incineration or landfill disposal. Even though all CE strategies strive to promote environmental sustainability, they might not be equally beneficial. Environmental data on different textile products is insufficiently available, which leads to complications when assessing and deciding on different CE strategies to be implemented. This paper studies the environmental impacts of a polyester T-shirt's linear life cycle through life cycle assessment (LCA) and evaluates the benefits attainable by adopting different CE strategies, and their order of priority, while noting uncertainty arising from poor data quality or unavailability. The LCA is complemented by assessing health and environmental risks related to the different options. Most of the linear life cycle's LCA-based impacts arise from use-phase washing. Hence, it is possible to reduce the environmental impact notably (37 %) by reducing the washing frequency. Adopting a CE strategy in which the shirt is reused by a second consumer, to double the number of uses, enables an 18 % impact reduction. Repurposing recycled materials to produce the T-shirt and recycling the T-shirt material itself emerged as the least impactful CE strategies. From the risk perspective, reusing the garment is the most efficient way to reduce environmental and health risks while washing frequency has a very limited effect. Combining different CE strategies offers the greatest potential for reducing both environmental impacts as well as risks. Data gaps and assumptions related to the use phase cause the highest uncertainty in the LCA results. To gain the maximum environmental benefits of utilizing CE strategies on polyester garments, consumer actions, design solutions, and transparent data sharing are needed.

Mitigating Ecotoxicity Risks of Pesticides on Ornamental Plants Based on Life Cycle Assessment

Ornamental plants such as floriculture and nurseries, have become increasingly popular, but their growth relies heavily on the use of many different types of pesticides. The widespread and inefficient use of these pesticides causes environmental pollution and damage to non-target organisms. Despite these impacts, there has been little research conducted on potential agrochemical pollution in the ornamental plant industry. To address this gap, a life cycle assessment (LCA) was conducted to evaluate the pesticide-related freshwater ecotoxicity impact of the US ornamental plant industry in comparison to that of major field crops. The study analyzed 195 pesticide active ingredients used in 15 major ornamental plant and four field crops. Results showed that the freshwater ecotoxicity per area (PAF m³ d/ha) of ornamental plants was significantly higher than that of field crops due to the high pesticide intensity (kg/ha) and ecotoxicity of insecticides and fungicides used in floriculture and nurseries. To mitigate environmental stress, minimizing the use of highly toxic pesticides is recommended. A ban on low-dose, high-toxicity pesticides could reduce pesticide-driven ecotoxicity by 34% and 49% for floriculture and nursery plants, respectively. This study is among the first to quantify the pesticide-driven ecotoxicity impacts of horticultural ornamental plants and proposes feasible ways to reduce these impacts, thus making the world more sustainable while still preserving its beauty.

Life cycle energy consumption, environmental impact, and costing assessment of coal to ethylene glycol processes via dimethyl oxalate and formaldehyde

The popularization of conventional dimethyl oxalate to ethylene glycol (DMOtEG) has kept ongoing in the past decade in China. Recently, a northern China factory in construction attracts attention using alternative formaldehyde to ethylene glycol (FtEG) route. Thus, a question arises about the individual comparative advantages of these two processes. So, this paper conducts a systematic modeling analysis of DMOtEG and FtEG, and the life cycle assessment is performed by SimaPro v9 to compare their impact. The results indicate the inferiority of life cycle energy consumption and life cycle cost of FtEG to those of DMOtEG due to the high energy consumption and pollutant emissions. Moreover, most impact categories of FtEG are worse than the DMOtEG as global warming, and photochemical oxidant formation potential. Despite this, FtEG still wins for better potentials in ozone formation, fine particulate matter formation, and terrestrial acidification because of less nitride emissions. In addition, the decrease in energy consumption and external cost will significantly decrease the life cycle cost under controllable catalyst costs of FtEG. These results describe the impact categories of DMOtEG and FtEG and provide a basis to help decision-makers develop coal to ethylene glycol processes.

Analyzing the relationship between product waste footprints and environmental damage - A life cycle analysis of 1,400+ products

A major problem for the circular economy is monitoring improvements in environmental sustainability. Measuring how much waste reduction efforts contribute to the decrease of environmental impact is difficult, because knowledge on whether life cycle waste amounts correlate with environmental damage is limited. In this article, product waste footprints are used to explore structural similarities and differences in associations with environmental damage. Using the waste flows linked to the production system of 1487 reference products from the Ecoinvent database, we found significant regression equations with R² of 0.75-0.89 between product waste footprints and potential impact on ecosystem diversity, human health and resource availability using log-transformed variables. For each 1 % increase in solid waste, potential impact on the environment increased by 0.75-0.84 %. This strong association between pre-consumer waste and environmental damage is particularly important for advocating for circular economy efforts at the point of consumption, where life cycle waste is invisible to consumers.

The environmental cost of unwarranted variation in the use of magnetic resonance imaging and computed tomography scans

BACKGROUND

Pollution is a major threat to global health, and there is growing interest on strategies to reduce emissions caused by health care systems. Unwarranted clinical variation, i.e. variation in the utilization of health services unexplained by differences in patient illness or preferences, may be an avoidable source of CO2 when related to overuse. Our objective was to evaluate the CO2 emissions attributable to unwarranted variation in the use of MRI and CT scans among countries of the G20-area.

METHODS

We selected seven countries of the G20-area with available data on the use of CT and MRI scans from the organization for Economic Co-operation and Development repository. Each nation's annual electric energy expenditure per 1000 inhabitants for such exams (T-En_ex-1000) was calculated and compared with the median and lowest value. Based on such differences we estimated the national energy and corresponding tons of CO2 that could be potentially avoided each year.

RESULTS

With available data we found a significant variation in T-En_ex-1000 (median value 1782 kWh, range 1200-3079 kWh) and estimated a significant amount of potentially avoidable emissions each year (range 2046-175120 tons of CO2). In practical terms such emissions would need, in the case of Germany, 71900 and 104210 acres of forest to be cleared from the atmosphere, which is 1.2 and 1.7 times the size of the largest German forest (Bavarian National Forest).

CONCLUSION

Among countries with a similar rate of development, unwarranted clinical variation in the use of MRI and CT scan causes significant emissions of CO2.

Comparing two types of mainstream disposable lunch boxes by LCA and exploring the possibility of converting carbon dioxide into products

Background

A disposable lunch box is an important cause of "white pollution". Many people consider that the disposable polylactic acid (PLA) lunch box is more environmentally friendly than the disposable paper pulp lunch box and can substitute for the latter.

Objective

We can determine whether PLA tableware is more environmentally friendly than paper tableware by analyzing the product life cycle of two tableware types. At the same time, as a continuous compound, carbon dioxide has significant commercial value. Carbon dioxide materials' applications range from beverages to cosmetics and building materials. The future application of carbon dioxide in the field of lunch boxes is discussed in this paper.

Methods

In this paper, the production stages of the two types of disposable lunch boxes were compared and surveyed using the life cycle assessment (LCA) method.

Conclusion

The results reveal that the main impact of the two types of lunch boxes is resource damage; the PLA lunch box is not better than the paper type; the production stage of the disposable PLA lunch box poses greater damage to the environment in all aspects than the paper type.

Discussion

Against the background of carbon neutrality and based on the constantly mature carbon dioxide conversion technology, the author explored the possibility of making products from carbon dioxide and proposed to make product designs based on carbon dioxide.

Life cycle cost analysis of solar energy via environmental externality monetization

Evaluating the embodied environmental impact of solar photovoltaic (PV) technology has been an important topic in addressing the sustainable development of renewable energy. While monetization of environmental externality is a remaining issue, which should be carried out in order to allow for an easy-to-understand comparison between direct economic and external cost. In this study, the environmental impact of solar PV power is monetized through conversion factors between midpoint and endpoint categories of life cycle analysis and the monetization weighting factor. Then, the power generation capacity and generation life of PV and coal-fired power plants are assumed to be consistent in order to compare the total cost of PV and coal-fired power generation. Results show that the cost of PV technology is higher than coal-fired form the base year from 2026 until 2030, taking into account environmental external costs and production costs. However, by 2030, the total cost of coal-fired power will be higher than that of solar PV. The life span cost per kWh is $3.55 for solar PV and $116.25 for coal-fired power. Although solar PV power seems more environmentally effective than coal-fired power in the life span, our results reveal the high environmental external cost of producing solar photovoltaic modules, which reminds us to pay more attention to the environmental impact when conducting cost-benefit analysis of renewable technologies. Without incorporating the environmental cost, the real cost of renewable technology will be underestimated.