Country-Specific External Costs of Abiotic Resource Use Based on User Cost Model in Life Cycle Impact Assessment

Abiotic resources are indispensable in society, but there are concerns regarding their depletion, scarcity, and increasing prices, resulting in potential economic damage in the future. To address these concerns, it is effective to consider the external costs of resource use. Although resource availability is different among mining sites, and local conditions are relevant in assessing resource scarcity, previous studies have assessed external costs and potential impacts of abiotic resource use globally. This study provides country-specific characterization factors (CFs) of abiotic resource use in life cycle impact assessment based on the user cost model, which represents the external costs of abiotic resource use to reflect country-specific resource scarcity. We demonstrate considerable variations in the CFs depending on the mining country, suggesting that the choice of mining country can affect external costs. The global external cost of abiotic resource use in 2020 was estimated at 1.9 trillion $, with a major contribution from the extraction of fossil fuels in the United States. Historical trends of the CFs and relevant parameters showed temporal fluctuations, emphasizing the importance of regularly updating the data underlying the calculation of the CFs. Country-level assessments of the external costs of resource use can contribute to discussions on the responsibilities of consuming countries by incorporating material footprint studies.

Environmental sustainability of diets among children and adolescents in the German DONALD cohort study: Age and time trends, and nutrient adequacy

BACKGROUND

Identifying diets beneficial for both human and planetary health has become increasingly important. However, to date, there is limited research on sustainable diets for children and adolescents, a vulnerable population group with specific nutritional needs.

OBJECTIVE

We aimed: to identify 1) the main determinants and 2) age and time trends of greenhouse gas emissions (GHGE), land use (LU), and water use (WU) of diets of children and adolescents, and 3) to analyze the associations of dietary GHGE, LU, and WU with nutrient adequacy.

METHODS

A total of 5,510 3-day-weighed dietary records (n=856; 6-17y; 48% ♀) of the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) study between 2000-2021 were analyzed. Values of GHGE (kgCO2eq), LU (m2 x year), and WU (L) determined by life cycle assessment were assigned to all recorded foods. For nutrient adequacy, the Mean Adequacy Ratio (MAR = ∑(nutrient intake / recommended intake) / number of nutrients) was used. Data were analyzed using polynomial mixed-effects regression models.

RESULTS

The main contributors to GHGE and LU were meat products (GHGE: 25.6%; LU: 32.8%), dairy products (22.2%; 17.7%), and sweets and pastries (14.0%; 14.3%); to WU, non-alcoholic beverages (24.3%), meat products (18.9%), and vegetables and fruits (17.7%). GHGE, LU, and WU per 1000kcal increased with age (p<0.01). GHGE and LU per 1000kcal increased between 2000-2010 and decreased thereafter in females (p<0.01) and males (GHGE only: p=0.02). No significant time trend was found for WU (p>0.05). A higher MAR was directly associated with GHGE/1000kcal (MAR: ß=0.011, 95%CI: 0.008-0.013, p<0.0001), LU/1000kcal (MAR: ß=0.009, 0.005-0.013, p<0.0001) and WU/1000kcal (MAR: ß=0.429, 0.325-0.533, p<0.0001).

CONCLUSION

Our findings underscore both the further need but also the capacity for change toward more environmentally sustainable diets. Yet, the trade-off between environmental sustainability and nutrient adequacy in diets of children and adolescents requires specific attention to dietary composition.

Teleconsultation for Preoperative Anesthesia Evaluation: Identifying Environmental Potentials by Life Cycle Assessment

Introduction: Teleconsultations for preoperative evaluation in anesthesiology proved to be feasible during the COVID-19 pandemic. However, widespread implementation of teleconsultations has not yet occurred. Besides time savings and economic benefits, teleconsultations in anesthesia may have the potential to reduce CO2 emissions. Methods: We conducted a life cycle assessment based on prospective surveys to assess the potential environmental benefits of preoperative anesthesia teleconsultations in comparison to the status-quo in-person consultations. Within 1 month, all patients presenting at the preoperative anesthesia clinic at RWTH Aachen University Hospital were asked about the distance traveled and mode of transportation to the hospital. The main outcome measure was the potential environmental benefit resulting from the implementation of teleconsultations. Results: In total, 821 out of 981 patients presenting at the anesthesia clinic participated in the survey. Most patients visited on an outpatient basis (62.9%) and traveled by car (81.7%). The median travel distance was 25 km [interquartile range 12-40]. If patients who came to the hospital solely for the anesthesia appointment had scheduled virtual appointments, the emissions of 3.03-ton CO2 equivalents (CO2-eq) could be avoided in the first month after implementation. The environmental impact associated with the production of teleconsultation equipment is outweighed by the reduction in patient travel. If all outpatient appointments were performed virtually, these savings would triple. Within 10 years, more than 1,300 tons CO2-eq could be avoided. Conclusion: Teleconsultations can mitigate the environmental impact of in-person anesthesia consultations. Further research is essential to leverage teleconsultations for preoperative evaluation also across other medical specialties.

The Impact of the Drying Process on the Antioxidant and Anti-Inflammatory Potential of Dried Ripe Coffee Cherry Pulp Soluble Powder

Coffee fruit cascara, which is the skin and pulp of the coffee cherry, has been authorized as a novel food for commercialization in the European Union. The present research assessed the feasibility of using spray drying to produce a soluble powder called instant cascara (IC), employing sun-dried ripe coffee cherry pulp as a raw material. Although there were no significant differences (p > 0.05) in the overall antioxidant capacity between the freeze-dried and spray-dried samples, after an in vitro simulation of the digestion process, the spray-dried sample was significantly (p < 0.05) more antioxidant. Both samples reduced physiological intracellular ROS and significantly decreased (p < 0.05) the secretion of the pro-inflammatory factor NO. Alkaloids and phenolic compounds were detected in intestinal digests. In conclusion, spray drying is a good technique for producing IC as its use does not affect its properties and causes less environmental impact than freeze drying, as calculated by life cycle assessment. Sensory analysis did not show significant differences between the commercial beverage and the IC beverage in the adult population. IC at 10 mg/mL was significantly less accepted in adolescents than the commercial beverage. Future work will include the reformulation of the IC beverage at 10 mg/mL, which has antioxidant and anti-inflammatory potential, to increase its hedonic acceptance in all consumer segments.

Toward Low-Carbon Rice Production in China: Historical Changes, Driving Factors, and Mitigation Potential

Under the "Double Carbon" target, the development of low-carbon agriculture requires a holistic comprehension of spatially and temporally explicit greenhouse gas (GHG) emissions associated with agricultural products. However, the lack of systematic evaluation at a fine scale presents considerable challenges in guiding localized strategies for mitigating GHG emissions from crop production. Here, we analyzed the county-level carbon footprint (CF) of China's rice production from 2007 to 2018 by coupling life cycle assessment and the DNDC model. Results revealed a significant annual increase of 74.3 kg CO2-eq ha-1 in the average farm-based CF (FCF), while it remained stable for the product-based CF (PCF). The CF exhibited considerable variations among counties, ranging from 2324 to 20,768 kg CO2-eq ha-1 for FCF and from 0.36 to 3.81 kg CO2-eq kg-1 for PCF in 2018. The spatiotemporal heterogeneities of FCF were predominantly influenced by field CH4 emissions, followed by diesel consumption and soil organic carbon sequestration. Scenario analysis elucidates that the national total GHG emissions from rice production could be significantly reduced through optimized irrigation (48.5%) and straw-based biogas production (18.0%). Moreover, integrating additional strategies (e.g., advanced crop management, optimized fertilization, and biodiesel application) could amplify the overall emission reduction to 76.7% while concurrently boosting the rice yield by 11.8%. Our county-level research provides valuable insights for the formulation of targeted GHG mitigation policies in rice production, thereby advancing the pursuit of carbon-neutral agricultural practices.

Environmental impacts of circularity strategies for social distancing plastic shields made of polymethyl methacrylate in the United States

One application of plastics that grew during the COVID-19 pandemic is for social distancing plastic shields, or protective barriers, made from polymethyl methacrylate (PMMA) such as transparent face guards. Although available for other applications, end-of-life impacts for barriers are currently lacking in the literature, and there is a need to fill in this gap to guide decisions. This study evaluated the end-of-life environmental impacts of PMMA barriers in the United States by using life cycle assessment. We evaluated five strategies including landfilling, waste-to-energy, mechanical recycling, chemical recycling and reuse. Data were sourced from literature and various life cycle inventory databases. The Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts (TRACI) was used as the life cycle impact assessment method. Landfilling exhibited the highest impact in all indicators and reuse demonstrated optimal results for global warming potential. A scenario analysis was conducted to explore a combination of strategies, revealing that the most promising approach involved a mix of 40% reuse, 20% mechanical recycling and 40% chemical recycling. Circular economy recommendations are proposed for managing these sources of plastic waste in the United States.

The carbon footprint of different modes of birth in the UK and the Netherlands: An exploratory study using life cycle assessment

OBJECTIVE

To compare the carbon footprint of caesarean and vaginal birth.

DESIGN

Life cycle assessment (LCA).

SETTING

Tertiary maternity units and home births in the UK and the Netherlands.

POPULATION

Birthing women.

METHODS

A cradle-to-grave LCA using openLCA software to model the carbon footprint of different modes of delivery in the UK and the Netherlands.

MAIN OUTCOME MEASURES

'Carbon footprint' (in kgCO2 equivalents [kgCO2 e]).

RESULTS

Excluding analgesia, the carbon footprint of a caesarean birth in the UK was 31.21 kgCO2 e, compared with 12.47 kgCO2 e for vaginal birth in hospital and 7.63 kgCO2 e at home. In the Netherlands the carbon footprint of a caesarean was higher (32.96 kgCO2 e), but lower for vaginal birth in hospital and home (10.74 and 6.27 kgCO2 e, respectively). Emissions associated with analgesia for vaginal birth ranged from 0.08 kgCO2 e (with opioid analgesia) to 237.33 kgCO2 e (nitrous oxide with oxygen). Differences in analgesia use resulted in a lower average carbon footprint for vaginal birth in the Netherlands than the UK (11.64 versus 193.26 kgCO2 e).

CONCLUSION

The carbon footprint of a caesarean is higher than for a vaginal birth if analgesia is excluded, but this is very sensitive to the analgesia used; use of nitrous oxide with oxygen multiplies the carbon footprint of vaginal birth 25-fold. Alternative methods of pain relief or nitrous oxide destruction systems would lead to a substantial improvement in carbon footprint. Although clinical need and maternal choice are paramount, protocols should consider the environmental impact of different choices.

What is the environmental impact of a blood transfusion? A life cycle assessment of transfusion services across England

BACKGROUND

Healthcare activities significantly contribute to greenhouse gas (GHG) emissions. Blood transfusions require complex, interlinked processes to collect, manufacture, and supply. Their contribution to healthcare emissions and avenues for mitigation is unknown.

STUDY DESIGN AND METHODS

We performed a life cycle assessment (LCA) for red blood cell (RBC) transfusions across England where 1.36 million units are transfused annually. We defined the process flow with seven categories: donation, transportation, manufacturing, testing, stockholding, hospital transfusion, and disposal. We used direct measurements, manufacturer data, bioengineering databases, and surveys to assess electrical power usage, embodied carbon in disposable materials and reagents, and direct emissions through transportation, refrigerant leakage, and disposal.

RESULTS

The central estimate of carbon footprint per unit of RBC transfused was 7.56 kg CO2 equivalent (CO2eq). The largest contribution was from transportation (2.8 kg CO2eq, 36% of total). The second largest was from hospital transfusion processes (1.9 kg CO2eq, 26%), driven mostly by refrigeration. The third largest was donation (1.3 kg CO2eq, 17%) due to the plastic blood packs. Total emissions from RBC transfusion are ~10.3 million kg CO2eq/year.

DISCUSSION

This is the first study to estimate GHG emissions attributable to RBC transfusion, quantifying the contributions of each stage of the process. Primary areas for mitigation may include electric vehicles for the blood service fleet, improving the energy efficiency of refrigeration, using renewable sources of electricity, changing the plastic of blood packs, and using methods of disposal other than incineration.

Environmental and Economic Viability of Using Concrete Block Wastes from a Concrete Production Plant as Recycled Coarse Aggregates

The construction sector must incorporate the circular economy to improve sustainability and efficiency. The use of recycled aggregates (RAs) as a substitute for natural aggregates (NAs) is currently being investigated and is expected to yield considerable benefits in the future. The objective of this research is to evaluate the environmental and economic benefits of using recycled coarse aggregates (RCAs) in different 1 m3 samples of concrete, substituting the natural coarse aggregate (NCAs) with RCAs in different percentages. RCAs generally come from the treatment of construction and demolition wastes (CDWs). However, in this research, the RCAs are the concrete block wastes (CBWs) generated by a concrete production plant. Among the most notable results is that compared to concrete with no RCAs, using alternatives in which RCAs have replaced 50% of the NCAs leads to an average decrease in impact category statistics of -3.30%. In contrast to the existing literature on the subject, the process of producing RCAs generated efficiency improvements in categories such as abiotic depletion of fossil fuels (-58.72%) and global warming potential (-85.13%). This is because the transport process, a key factor in determining the viability of using RAs instead of NAs, was eliminated. In economic terms, there is a slight decrease in the financial cost of producing 1 m3 of concrete as the quantity of RCAs increases. The maximum decrease was 0.23€/m3 in the samples studied. Combining both the environmental and economic aspects resulted in a reduction factor of 0.420 g of CO2/€cent, which means fewer CO2 emissions per unit cost when using RCAs. In conclusion, these results are intended to further knowledge in the field of using RAs instead of NAs in order to help the sector achieve sustainability and find an alternative use for a particular type of business waste.

Life cycle assessment of iron-biomass supported catalyst for Fischer Tropsch synthesis

The iron-based biomass-supported catalyst has been used for Fischer-Tropsch synthesis (FTS). However, there is no study regarding the life cycle assessment (LCA) of biomass-supported iron catalysts published in the literature. This study discusses a biomass-supported iron catalyst's LCA for the conversion of syngas into a liquid fuel product. The waste biomass is one of the source of activated carbon (AC), and it has been used as a support for the catalyst. The FTS reactions are carried out in the fixed-bed reactor at low or high temperatures. The use of promoters in the preparation of catalysts usually enhances C5+ production. In this study, the collection of precise data from on-site laboratory conditions is of utmost importance to ensure the credibility and validity of the study's outcomes. The environmental impact assessment modeling was carried out using the OpenLCA 1.10.3 software. The LCA results reveals that the synthesis process of iron-based biomass supported catalyst yields a total impact score in terms of global warming potential (GWP) of 1.235E + 01 kg CO2 equivalent. Within this process, the AC stage contributes 52% to the overall GWP, while the preparation stage for the catalyst precursor contributes 48%. The comprehensive evaluation of the iron-based biomass supported catalyst's impact score in terms of human toxicity reveals a total score of 1.98E-02 kg 1,4-dichlorobenzene (1,4-DB) equivalent.

Bayesian Optimization of Environmentally Sustainable Graphene Inks Produced by Wet Jet Milling

Liquid phase exfoliation (LPE) of graphene is a potentially scalable method to produce conductive graphene inks for printed electronic applications. Among LPE methods, wet jet milling (WJM) is an emerging approach that uses high-speed, turbulent flow to exfoliate graphene nanoplatelets from graphite in a continuous flow manner. Unlike prior WJM work based on toxic, high-boiling-point solvents such as n-methyl-2-pyrollidone (NMP), this study uses the environmentally friendly solvent ethanol and the polymer stabilizer ethyl cellulose (EC). Bayesian optimization and iterative batch sampling are employed to guide the exploration of the experimental phase space (namely, concentrations of graphite and EC in ethanol) in order to identify the Pareto frontier that simultaneously optimizes three performance criteria (graphene yield, conversion rate, and film conductivity). This data-driven strategy identifies vastly different optimal WJM conditions compared to literature precedent, including an optimal loading of 15 wt% graphite in ethanol compared to 1 wt% graphite in NMP. These WJM conditions provide superlative graphene production rates of 3.2 g hr-1 with the resulting graphene nanoplatelets being suitable for screen-printed micro-supercapacitors. Finally, life cycle assessment reveals that ethanol-based WJM graphene exfoliation presents distinct environmental sustainability advantages for greenhouse gas emissions, fossil fuel consumption, and toxicity.

Climate Impacts of Hydrogen and Methane Emissions Can Considerably Reduce the Climate Benefits across Key Hydrogen Use Cases and Time Scales

Recent investments in "clean" hydrogen as an alternative to fossil fuels are driven by anticipated climate benefits. However, most climate benefit calculations do not adequately account for all climate warming emissions and impacts over time. This study reanalyzes a previously published life cycle assessment as an illustrative example to show how the climate impacts of hydrogen deployment can be far greater than expected when including the warming effects of hydrogen emissions, observed methane emission intensities, and near-term time scales; this reduces the perceived climate benefits upon replacement of fossil fuel technologies. For example, for blue (natural gas with carbon capture) hydrogen pathways, the inclusion of upper-end hydrogen and methane emissions can yield an increase in warming in the near term by up to 50%, whereas lower-end emissions decrease warming impacts by at least 70%. For green (renewable-based electrolysis) hydrogen pathways, upper-end hydrogen emissions can reduce climate benefits in the near term by up to 25%. We also consider renewable electricity availability for green hydrogen and show that if it is not additional to what is needed to decarbonize the electric grid, there may be more warming than that seen with fossil fuel alternatives over all time scales. Assessments of hydrogen's climate impacts should include the aforementioned factors if hydrogen is to be an effective decarbonization tool.

Automated Laboratory Kilogram-Scale Graphene Production from Coal

The flash Joule heating (FJH) method converts many carbon feedstocks into graphene in milliseconds to seconds using an electrical pulse. This opens an opportunity for processing low or negative value resources, such as coal and plastic waste, into high value graphene. Here, a lab-scale automation FJH system that allows the synthesis of 1.1 kg of turbostratic flash graphene from coal-based metallurgical coke (MC) in 1.5 h is demonstrated. The process is based on the automated conversion of 5.7 g of MC per batch using an electrical pulse width modulation system to conduct the bottom-up upcycle of MC into flash graphene. This study then compare this method to two other scalable graphene synthesis techniques by both a life cycle assessment and a technoeconomic assessment.

Techno-Environmental Evaluation of Alkaline Treatment in Flax Reinforced Thermoplastics

A combination of thermoplastics and natural fiber reinforcements is considered an ideal choice to mitigate environmental impacts and enhance recyclability or reusability. Chemical treatments are often employed to enhance the thermomechanical properties of natural fiber-reinforced plastics. Nevertheless, it is of paramount importance to assess the techno-economic impact of such chemical treatments and environmentally friendly materials for their implementation in mass productions on an industrial scale. In this work, high-density polyethylene is reinforced with sodium hydroxide (NaOH)-treated and untreated flax fibers to study its impact on mechanical and environmental properties. The composites treated with NaOH exhibited a 37% increase in tensile strength. However, life cycle assessment performed on the NaOH-treated samples showed that they had a global warming potential of 5.8 kg of CO2, a terrestrial acidification potential of 0.0269 kg of SO2, and a human carcinogenic toxicity of 0.031 kg of 1,4-DCB compared to the untreated samples. In summary, the techno-environmental analysis reveals a novel approach to identifying chemical treatments based on their technical and environmental effects.

Cleaning up while Changing Gears: The Role of Battery Design, Fossil Fuel Power Plants, and Vehicle Policy for Reducing Emissions in the Transition to Electric Vehicles

Plug-in electric vehicles (PEVs) can reduce air emissions when charged with clean power, but prior work estimated that in 2010, PEVs produced 2 to 3 times the consequential air emission externalities of gasoline vehicles in PJM (the largest US regional transmission operator, serving 65 million people) due largely to increased generation from coal-fired power plants to charge the vehicles. We investigate how this situation has changed since 2010, where we are now, and what the largest levers are for reducing PEV consequential life cycle emission externalities in the near future. We estimate that PEV emission externalities have dropped by 17% to 18% in PJM as natural gas replaced coal, but they will remain comparable to gasoline vehicle externalities in base case trajectories through at least 2035. Increased wind and solar power capacity is critical to achieving deep decarbonization in the long run, but through 2035 we estimate that it will primarily shift which fossil generators operate on the margin at times when PEVs charge and can even increase consequential PEV charging emissions in the near term. We find that the largest levers for reducing PEV emissions over the next decade are (1) shifting away from nickel-based batteries to lithium iron phosphate, (2) reducing emissions from fossil generators, and (3) revising vehicle fleet emission standards. While our numerical estimates are regionally specific, key findings apply to most power systems today, in which renewable generators typically produce as much output as possible, regardless of the load, while dispatchable fossil fuel generators respond to the changes in load.

Environmental Sustainability of π-Electron Donor-Based Deep Eutectic Solvents for Toluene Absorption: A Life-Cycle Perspective

The novel π-electron donor-based deep eutectic solvents (DESs) have been shown to be a promising type of absorbent with excellent performance on toluene absorption. However, their greenness or sustainability is still unclear. Thus, to bridge the gap and give a comprehensive evaluation for their industrialization potential, the life cycle assessment (LCA) was used to evaluate the potential environmental impacts incurred from their production and usage for absorbing toluene. The environmental profiles are also compared with that of popular choline chloride (ChCl) based DES, common organic solvent triethylene glycol (TEG) and ionic liquid ([EMIM][Tf2 N]). The results indicate that among the involved hydrogen bond acceptors (HBAs), TEBAC generally imparts lower environmental impacts than other HBAs but has higher impacts than ChCl. Although TEBAC-PhOH is not the most environmentally friendly absorbent during the production stage, its outstanding absorption performance minimizes the environmental impact when absorbing the same mass of toluene. Furthermore, the environmental impacts of the toluene absorption process using TEBAC-PhOH is significantly lower than that of [EMIM][Tf2 N], slightly lower than TEG. Therefore, considering both absorption performance and environmental impacts, TEBAC-PhOH can be used as a promising "green and sustainable" toluene absorbent to traditional absorbents and ionic liquids.

Enhanced Deep-Learning Model for Carbon Footprints of Chemicals

Millions of chemicals have been designed; however, their product carbon footprints (PCFs) are largely unknown, leaving questions about their sustainability. This general lack of PCF data is because the data needed for comprehensive environmental analyses are typically not available in the early molecular design stages. Several predictive tools have been developed to estimate the PCF of chemicals, which are applicable to only a narrow range of common chemicals and have limited predictive ability. Here, we propose FineChem 2, which is based on a novel transformer framework and first-hand industry data, for accurately predicting the PCF of chemicals. Compared to previous tools, FineChem 2 demonstrates significantly better predictive power, and its applicability domains are improved by ∼75% on a diverse set of chemicals on the global market, including the high-production-volume chemicals identified by regulators, daily chemicals, and chemical additives in food and plastics. In addition, through better interpretability from the attention mechanism, FineChem 2 may successfully identify PCF-intensive substructures and critical raw materials of chemicals, providing insights into the design of more sustainable molecules and processes. Therefore, we highlight FineChem 2 for estimating the PCF of chemicals, contributing to advancements in the sustainable transition of the global chemical industry.

Solar-Powered Direct Air Capture: Techno-Economic and Environmental Assessment

Direct air capture (DAC) of CO2 has gained attention as a sustainable carbon source. One of the most promising technologies currently available is liquid solvent DAC (L-DAC), but the significant fraction of fossil CO2 in the output stream hinders its utilization in carbon-neutral fuels and chemicals. Fossil CO2 is generated and captured during the combustion of fuels to calcine carbonates, which is difficult to decarbonize due to the high temperatures required. Solar thermal energy can provide green high-temperature heat, but it flourishes in arid regions where environmental conditions are typically unfavorable for L-DAC. This study proposes a solar-powered L-DAC approach and develops a model to assess the influence of the location and plant capacity on capture costs. The performed life cycle assessment enables the comparison of technologies based on net CO2 removal, demonstrating that solar-powered L-DAC is not only more environmentally friendly but also more cost-effective than conventional L-DAC.

The Environmental Impacts of Electronic Medical Records Versus Paper Records at a Large Eye Hospital in India: Life Cycle Assessment Study

BACKGROUND

Health care providers worldwide are rapidly adopting electronic medical record (EMR) systems, replacing paper record-keeping systems. Despite numerous benefits to EMRs, the environmental emissions associated with medical record-keeping are unknown. Given the need for urgent climate action, understanding the carbon footprint of EMRs will assist in decarbonizing their adoption and use.

OBJECTIVE

We aimed to estimate and compare the environmental emissions associated with paper medical record-keeping and its replacement EMR system at a high-volume eye care facility in southern India.

METHODS

We conducted the life cycle assessment methodology per the ISO (International Organization for Standardization) 14040 standard, with primary data supplied by the eye care facility. Data on the paper record-keeping system include the production, use, and disposal of paper and writing utensils in 2016. The EMR system was adopted at this location in 2018. Data on the EMR system include the allocated production and disposal of capital equipment (such as computers and routers); the production, use, and disposal of consumable goods like paper and writing utensils; and the electricity required to run the EMR system. We excluded built infrastructure and cooling loads (eg. buildings and ventilation) from both systems. We used sensitivity analyses to model the effects of practice variation and data uncertainty and Monte Carlo assessments to statistically compare the 2 systems, with and without renewable electricity sources.

RESULTS

This location's EMR system was found to emit substantially more greenhouse gases (GHGs) than their paper medical record system (195,000 kg carbon dioxide equivalents [CO2e] per year or 0.361 kg CO2e per patient visit compared with 20,800 kg CO2e per year or 0.037 kg CO2e per patient). However, sensitivity analyses show that the effect of electricity sources is a major factor in determining which record-keeping system emits fewer GHGs. If the study hospital sourced all electricity from renewable sources such as solar or wind power rather than the Indian electric grid, their EMR emissions would drop to 24,900 kg CO2e (0.046 kg CO2e per patient), a level comparable to the paper record-keeping system. Energy-efficient EMR equipment (such as computers and monitors) is the next largest factor impacting emissions, followed by equipment life spans. Multimedia Appendix 1 includes other emissions impact categories.

CONCLUSIONS

The climate-changing emissions associated with an EMR system are heavily dependent on the sources of electricity. With a decarbonized electricity source, the EMR system's GHG emissions are on par with paper medical record-keeping, and decarbonized grids would likely have a much broader benefit to society. Though we found that the EMR system produced more emissions than a paper record-keeping system, this study does not account for potential expanded environmental gains from EMRs, including expanding access to care while reducing patient travel and operational efficiencies that can reduce unnecessary or redundant care.

Carbon footprint of Nepalese healthcare system: A study of Dhulikhel Hospital

Background

Though direct greenhouse gas emissions cannot be observed in health care sectors, there can exist indirect emissions contributing to global climate change. This study addresses the concept of the carbon footprint and its significance in understanding the environmental impact of human activities, with a specific emphasis on the healthcare sector through gate-to-gate (GtoG) life cycle assessment. Transportation, energy consumption, and solid waste generated by hospitals are the primary sources of carbon emissions.

Methods

Different standards, guidelines and parameters were used to estimate emissions from both the primary and secondary data. All steps and sub-steps involved in GtoG were accessed and analyzed within the standard ISO 14040:44 guideline. An extensive review of existing literature was carried out for the evaluation and verification of secondary data.

Results

The total carbon footprint of generators, electricity consumption, transportation activities, LPG cylinders, PV systems was found to be 58,780 kg-CO2-eq/yr, 519,794 kg-CO2-eq/yr, 272,375 kg-CO2-eq/yr, 44,494 kg-CO2-eq/yr, 35,283 kg-CO2-eq/yr respectively and the emissions from non-biodegradable solid waste was found to be 489,835 kg-CO2/yr. Local air pollutants such as PM 10, CO, SO 2, NO X, and VOCs generated by generators and transportation were also estimated. The CH 4 emissions from liquid waste were 1177.344 kg CH 4/BOD yr, and those from biodegradables were 3821.6954 kg CH4/yr.

Conclusions

Healthcare professionals and policymakers can take action to reduce the sector's carbon footprint by implementing best practices and encouraging sustainable behavior. This study can be taken as foundation for further exploration of indirect emissions from healthcare sectors not only in Nepal but also in south Asian scenario.

Toward sustainable household laundry. Washing quality vs. environmental impacts

We tested the efficacy of standard soil removal and bacterial reduction from textile. A life cycle analysis for different washing cycles was also performed. The results show that washing at 40 °C and 10 g/L was the most effective and resulted in good removal of standard soiling. However, bacteria reduction was highest at 60 °C, 5 g/L and 40 °C, 20 g/L (> 5 log CFU/carrier). With the 40 °C, 10 g/L scenario, we approached the standard requirements for household laundry of ~ 4 log CFU/carrier reduction and good soil removal. Howsoever, life cycle analysis shows that washing at 40 °C and 10 g/L has a higher environmental impact than 60 °C and 5 g/L due to the significant contribution of the detergent. Reducing energy consumption and reformulation of detergents needs to be implemented in the household laundry to achieve sustainable washing without compromising the quality.

Life Cycle Greenhouse Gas Emissions of CO2-Enabled Sedimentary Basin Geothermal

The expansion of renewable energy and the large-scale deployment of carbon dioxide (CO2) capture and storage (CCS) can decarbonize the power sector. The use of CO2 to extract geothermal heat from naturally porous and permeable sedimentary basins to generate electricity (CO2-plume geothermal (CPG) system) presents an opportunity to simultaneously generate renewable energy and geologically store CO2. In this study, we estimate the life cycle greenhouse gas (GHG) impacts of CPG systems through 12 scenarios in which CPG systems are combined with one of six CO2 sources (e.g., bioenergy with carbon capture and storage (BECCS) and iron and steel facilities) and operate in two geological settings. We find the life cycle GHG emissions of CPG systems ranging from -0.25 to -6.18 kg CO2eq/kWh. CPG systems can achieve the highest emissions reductions when utilizing the CO2 captured from BECCS. We evaluate uncertainty through a Monte Carlo simulation, demonstrating consistent net reductions in life cycle emissions and a local, one-parameter-at-a-time sensitivity analysis that identifies the CO2 capture capacity as the high-impact parameter of the results. Through the production of electricity, CPG systems can provide additional environmental benefits to the deployment of large-scale CCS.

Regulation Mechanism for Designing Decarbonization Pathways in the Copper Industry Toward Carbon Neutrality

The transformation of the global power structure caused by the carbon neutrality goal will promote copper consumption. It is crucial to explore the decarbonization pathways of the copper industry to help fulfill greenhouse gas (GHG) emission reduction targets. This study utilized material flow analysis and life cycle assessment methods to investigate 12 different subscenarios based on international trade, circular economy, technology evolution, and environmental market factors. Policy combination scenario is employed to reveal the mechanism of decarbonization. The results show that refined copper consumption in China is expected to increase by 62.3% in 2060 compared to 2020. The GHG emissions of China's copper industry will reach 9.1 million tonnes (Mt) CO2e in 2060, technology evolution and environmental market are crucial for realizing carbon neutrality goal of this industry, accounting for 26.4 and 47.2% of emissions reductions, respectively, between 2020 and 2060. International trade and circular economy play important roles in the high-quality carbon peaking stage; however, imported copper and domestic secondary copper will constitute the basic supply of copper resources in China in the long run, and the comparative advantages of them will gradually weaken. Policy combination scenario can achieve the incentive synergy effect, with GHG reduced to 0.5 Mt CO2e in 2060. The enhanced application of policies such as material substitution and carbon emission trading will further promote industry to achieve net-zero GHG emission. We suggest regulating the industry's structure based on the international systemic circulation pattern and accelerating the construction of a green circular chain in the short term to achieve sustainable copper supply and high-quality carbon peaking. Promoting a high-quality technology development strategy and enhancing the environmental markets are recommended in the long term to achieve carbon neutrality.

Gold Recovery from E-Waste by Food-Waste Amyloid Aerogels

Demand for gold recovery from e-waste grows steadily due to its pervasive use in the most diverse technical applications. Current methods of gold recovery are resource-intensive, necessitating the development of more efficient extraction materials. This study explores protein amyloid nanofibrils (AF) derived from whey, a dairy industry side-stream, as a novel adsorbent for gold recovery from e-waste. To do so, AF aerogels are prepared and assessed against gold adsorption capacity and selectivity over other metals present in waste electrical and electronic equipment (e-waste). The results demonstrate that AF aerogel has a remarkable gold adsorption capacity (166.7 mg g-1 ) and selectivity, making it efficient and an adsorbent for gold recovery. Moreover, AF aerogels are efficient templates to convert gold ions into single crystalline flakes due to Au growth along the (111) plane. When used as templates to recover gold from e-waste solutions obtained by dissolving computer motherboards in suitable solvents, the process yields high-purity gold nuggets, constituted by ≈90.8 wt% gold (21-22 carats), with trace amounts of other metals. Life cycle assessment and techno-economic analysis of the process finally consolidate the potential of protein nanofibril aerogels from food side-streams as an environmentally friendly and economically viable approach for gold recovery from e-waste.

Minimizing the Environmental Impacts of Plastic Pollution through Ecodesign of Products with Low Environmental Persistence

While plastic pollution threatens ecosystems and human health, the use of plastic products continues to increase. Limiting its harm requires design strategies for plastic products informed by the threats that plastics pose to the environment. Thus, we developed a sustainability metric for the ecodesign of plastic products with low environmental persistence and uncompromised performance. To do this, we integrated the environmental degradation rate of plastic into established material selection strategies, deriving material indices for environmental persistence. By comparing indices for the environmental impact of on-the-market plastics and proposed alternatives, we show that accounting for the environmental persistence of plastics in design could translate to societal benefits of hundreds of millions of dollars for a single consumer product. Our analysis identifies the materials and their properties that deserve development, adoption, and investment to create functional and less environmentally impactful plastic products.

Materials Science Toolkit for Carbon Footprint Assessment: A Case Study for Endoscopic Accessories of Common Use

Ironically, healthcare systems are key agents in respiratory-related diseases and estimated deaths because of the high impact of their greenhouse gas emissions, along with industry, transportation, and housing. Based on safety requirements, hospitals and related services use an extensive number of consumables, most of which end up incinerated at the end of their life cycle. A thorough assessment of the carbon footprint of such devices typically requires knowing precise information about the manufacturing process, which is rarely available in detail because of the many materials, pieces, and steps involved during the fabrication. Yet, the tools most often used for determining the environmental impact of consumer goods require a bunch of parameters, mainly based on the material composition of the device. Here, we report a basic set of analytical methods that provide the information required by the software OpenLCA to calculate the main outcome related to environmental impact, greenhouse gas emissions. Through thermogravimetry, calorimetry, infrared spectroscopy, and elemental analysis, we proved that obtaining relevant data for the calculator in the exemplifying case of endoscopy tooling or accessories is possible. This routine procedure opens the door to a broader, more accurate analysis of the environmental impact of everyday work at hospital services, offering potential alternatives to minimize it.

Fifty years of environmental progress for United States dairy farms

Dairy farms in the United States (US) have changed in many ways over the past 50 years. Milk production efficiency has increased greatly with about 30% fewer cows producing about twice the amount of milk today. Other improvements include increases in crop yields, fuel efficiency of farm equipment and efficiency in producing most resources used on farms (electricity, fuel, fertilizer, etc.). These improvements have led to changes in the environmental impact of farms. Through simulation of representative dairy farms in 1971 and 2020, changes in nutrient losses and farmgate life cycle assessments of greenhouse gas (GHG) emissions, fossil energy use, and blue (ground and surface) water use were determined for 6 regions and the US For all environmental metrics studied, intensities expressed per unit of fat and protein corrected milk produced were reduced, but the total impacts over all farms or milk produced increased for 5 of the 13 environmental metrics. Reductions in the impacts of dairy farms in the eastern US were offset by large increases in western regions because of a major increase in cow numbers in the west. The national average intensity of GHG emissions decreased by 42%, which gave just a 14% increase in the total GHG emission of all dairy farms over the 50-yr period. The intensity of fossil energy use decreased by 54% with the total for all farms decreasing 9%. Water use related to milk production decreased in intensity by 28%, but due to the large increase in dairy production in the dry western regions with greater dependence on irrigated feed crops, total blue water use increased 42%. Major pathways of nitrogen loss included ammonia volatilization, leaching, and denitrification, where total ammonia emissions related to US dairy farms increased 29% while leaching losses decreased by 39% with little change in nitrous oxide emission. Simulated nitrogen and phosphorus runoff losses totaled for all dairy farms decreased 27 to 51% through more efficient fertilizer use, reduced tillage, and greater use of cover crops. Emissions of methane and reactive non-methane volatile organic compounds increased 32% and 53%, respectively, due to greater use of long-term manure storage and silage stored in bunkers and piles. Although much progress has been made in improving production efficiency, continued improvement with new strategies and technologies are needed to meet the demand for dairy products while mitigating total environmental impacts, particularly in view of projected climate variability.

Effect of a Garlic and Citrus Extract Supplement on the Lactation Performance and Carbon Footprint of Dairy Cows under Grazing Conditions in Chile

Two trials were conducted to evaluate the effect of a garlic and citrus extract supplement (GCE) on the milk production performance and carbon footprint of grazing dairy cows in a Chilean commercial farm. A total of 36 early- to mid-lactation and 54 late-lactation Irish Holstein-Friesian cows were used in Trial 1 and Trial 2, respectively. In both trials, the cows were reared under grazing conditions and offered a supplementary concentrate without or with GCE (33 g/cow/d) for 12 weeks. The concentrate was fed in the afternoon when the cows visited the milking parlour. Consequently, the results of milk production performance in these trials were used to determine the effect of feeding with GCE on the carbon footprint (CFP) of milk using a life cycle assessment (LCA) model. In Trial 1 and Trial 2, feeding with GCE increased estimated dry matter intake (DMI, kg/d) by 8.15% (18.4 vs. 19.9) and 15.3% (15.0 vs. 17.3), energy-corrected milk (ECM, kg/d) by 11.4% (24.5 vs. 27.3) and 33.5% (15.5 vs. 20.7), and feed efficiency (ECM/DMI) by 3.03% (1.32 vs. 1.36) and 17.8% (1.01 vs. 1.19), respectively. The LCA revealed that feeding with GCE reduced the emission intensity of milk by 8.39% (1.55 vs. 1.42 kg CO2-eq/kg ECM). Overall, these results indicate that feeding with GCE improved the production performance and CFP of grazing cows under the conditions of the current trials.

Eco-Friendly Method for Wood Aerogel Preparation with Efficient Catalytic Reduction of 4-Nitrophenol

The advancement of science and technology and the growth of industry have led to an escalating discharge of domestic sewage and industrial wastewater containing dyes. This surge in volume not only incurs higher costs but also exacerbates environmental burdens. However, the benefits of green and reusable catalytic reduction materials within dye processes are still uncertain. Herein, this study utilized the eco-friendly deep eutectic solvent method (DESM) and the chlorite-alkali method (CAM) to prepare a cellulose-composed wood aerogel derived from natural wood for 4-nitrophenol (4-NP) reduction. The life cycle assessment of wood aerogel preparative process showed that the wood aerogel prepared by the one-step DESM method had fewer environmental impacts. The CAM method was used innovatively to make uniform the chemical functional groups of different wood species and various wood maturities. Subsequently, palladium nanoparticles (Pd NPs) were anchored in the skeleton structure of the wood aerogel with the native chemical groups used as a reducing agent to replace external reducing agents, which reduced secondary pollution and prevented the agglomeration of nanoparticles. Results showed that the catalytic reduction efficiency of 4-NP can reach 99.8%, which shows promises for applications in wastewater treatment containing dyes. Moreover, investigation of the advantages of preparation methods of wood aerogel has important implications for helping researchers and producers choose suitable preparation strategies according to demand.

Postpandemic Evaluation of the Eco-Efficiency of Personal Protective Equipment Against COVID-19 in Emergency Departments: Proposal for a Mixed Methods Study

BACKGROUND

The COVID-19 pandemic has had a profound impact on emergency department (ED) care in Canada and around the world. To prevent transmission of COVID-19, personal protective equipment (PPE) was required for all ED care providers in contact with suspected cases. With mass vaccination and improvements in several infection prevention components, our hypothesis is that the risks of transmission of COVID-19 will be significantly reduced and that current PPE use will have economic and ecological consequences that exceed its anticipated benefits. Evidence is needed to evaluate PPE use so that recommendations can ensure the clinical, economic, and environmental efficiency (ie, eco-efficiency) of its use.

OBJECTIVE

To support the development of recommendations for the eco-efficient use of PPE, our research objectives are to (1) estimate the clinical effectiveness (reduced transmission, hospitalizations, mortality, and work absenteeism) of PPE against COVID-19 for health care workers; (2) estimate the financial cost of using PPE in the ED for the management of suspected or confirmed COVID-19 patients; and (3) estimate the ecological footprint of PPE use against COVID-19 in the ED.

METHODS

We will conduct a mixed method study to evaluate the eco-efficiency of PPE use in the 5 EDs of the CHU de Québec-Université Laval (Québec, Canada). To achieve our goals, the project will include four phases: systematic review of the literature to assess the clinical effectiveness of PPE (objective 1; phase 1); cost estimation of PPE use in the ED using a time-driven activity-based costing method (objective 2; phase 2); ecological footprint estimation of PPE use using a life cycle assessment approach (objective 3; phase 3); and cost-consequence analysis and focus groups (integration of objectives 1 to 3; phase 4).

RESULTS

The first 3 phases have started. The results of these phases will be available in 2023. Phase 4 will begin in 2023 and results will be available in 2024.

CONCLUSIONS

While the benefits of PPE use are likely to diminish as health care workers' immunity increases, it is important to assess its economic and ecological impacts to develop recommendations to guide its eco-efficient use.

TRIAL REGISTRATION

PROSPERO CRD42022302598; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=302598.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50682.

Biodiversity Impact Assessment Considering Land Use Intensities and Fragmentation

Land use is a major threat to terrestrial biodiversity. Life cycle assessment is a tool that can assess such threats and thereby support environmental decision-making. Within the Global Guidance for Life Cycle Impact Assessment (GLAM) project, the Life Cycle Initiative hosted by UN Environment aims to create a life cycle impact assessment method across multiple impact categories, including land use impacts on ecosystem quality represented by regional and global species richness. A working group of the GLAM project focused on such land use impacts and developed new characterization factors to combine the strengths of two separate recent advancements in the field: the consideration of land use intensities and land fragmentation. The data sets to parametrize the underlying model are also updated from previous models. The new characterization factors cover five species groups (plants, amphibians, birds, mammals, and reptiles) and five broad land use types (cropland, pasture, plantations, managed forests, and urban land) at three intensity levels (minimal, light, and intense). They are available at the level of terrestrial ecoregions and countries. This paper documents the development of the characterization factors, provides practical guidance for their use, and critically assesses the strengths and remaining shortcomings.

[Effect of single basal application of controlled-release blended fertilizer on reactive nitrogen loss, carbon and nitrogen footprint during summer maize growth period]

To elucidate the agronomic and environmental effects of single basal application of controlled-release blended fertilizer in summer maize, and optimize management measures of nitrogen fertilizer for grain production in North China Plain, we conducted a field experiment in Dezhou Modern Agricultural Science and Technology Park in Shandong Province. There were four treatments: CK (no N fertilizer), FFP (farmer's fertilizing practice, 240 kg N·hm-2), OPT (optimized nitrogen application, 210 kg N·hm-2), and CRBF (controlled-release blended fertilizer with single basal application, 210 kg N·hm-2). We compared maize yield and reactive nitrogen loss, and quantitatively evaluated the carbon and nitrogen footprints by using life cycle assessment method. The results showed that nitrogen application significantly increased summer maize yield. Compared with FFP, OPT and CRBF increased summer corn yield by 0.7% and 2.9%, respectively, decreased the total amount of ammonia volatilization, N2O emission, and nitrate leaching by 13.0% and 72.7%, 13.3% and 37.5%, 20.5% and 23.5% respectively. Compared with CK, nitrogen application significantly increased the global warming potential (GWP) of summer maize production. Compared with FFP, GWP and greenhouse gas emission intensity of OPT decreased by 3.8% and 4.2%, while the reduction of CRBF were 8.7% and 12.0%, respectively. Compared with CK, nitrogen application significantly increased the carbon and nitrogen footprint of summer maize production. The production and transportation of nitrogen fertilizer and soil greenhouse gas emission were the main contributing factors of the carbon footprint, with contribution rates of 54%-60% and 24%-31%, respectively. Nitrate leaching was the main contributing factor of nitrogen footprint, with contribution rate of 57%-94%. Compared with FFP, the carbon and nitrogen footprints of OPT and CRBF were reduced by 11.0% and 16.5%, 19.6% and 28.4%, respectively. Considering the yield, reactive nitrogen loss and carbon and nitrogen footprint, we recommended the single basal application of controlled-release blended fertilizer as an effective nitrogen fertilizer management measure to promote grain clean production in the North China Plain.

Assessment of carbon footprint of milk production and identification of its major determinants in smallholder dairy farms in Karnataka, India

Indian dairy enterprise is dominated by smallholder dairy farms that contribute 72% of the country's total milk production. These smallholder dairy farms are often considered to emit substantial greenhouse gases (GHG) but are poor in productive performances. Therefore, it is crucial to estimate the carbon footprint (CF) of milk production of the smallholder Indian dairy farms. The primary objectives of the study were (1) Assessing the CF of milk production of smallholder dairy farms through life cycle analysis in south-interior Karnataka, India; (2) Identifying the hotspots of GHG emissions and significant factors influencing the CF of milk production in smallholder dairy production system. The study accounted GHG emissions from different sources and considered multiple functions of the smallholder production system. Estimations were made based on primary data collected from 47 farms and associated secondary data. For estimating the CF of milk production, the emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) on a CO2-equivalent (CO2-eq) basis from feed production, enteric fermentation, manure management, transport and energy usage were allocated to fat- and protein-corrected milk (FPCM) based on mass balance, price (crop byproducts and residues) and feed digestibility. Principal component analysis and stepwise linear regression analysis were performed to identify the major factors influencing the CF. The average total GHG emissions (kg CO2-eq yr-1 farm-1) attributable to milk production based on mass, economic, and digestibility allocations were 8,936, 8,641, and 8,759, respectively. The contributions of CH4, N2O, and CO2 to the total farm GHG emission were 70.6%, 20.5%, and 7.69%, respectively. The major emission hotspots were CH4 emission from enteric fermentation (66.8%) and GHG emission from feed production (23.0%). The average CF of cradle-to-dairy cooperative milk production varied from 1.45 to 1.81 kg CO2-eq kg FPCM-1. The CF of milk production was more than 2-fold greater, when milk yield was below 3,500 kg lactating cow-1 yr-1. The FPCM yield 100 kg body weight-1, dry matter intake, and CH4 emission from manure management were the strongest determinants of the CF and explained 83.4% of the observed variation. The study emphasized the importance of considering multiple functions of a mixed crop-livestock-based dairy production system for estimating CF per unit of product. The results suggest that maintaining high-yielding dairy animals and adopting appropriate feeding strategies for better feed utilization are the possible effective interventions for reducing the CF of milk production.

Biochar-integrated reactive filtration of wastewater for P removal and recovery, micropollutant catalytic oxidation, and negative CO2 e: Life cycle assessment and techno-economic analysis

Life cycle assessment (LCA) and techno-economic analysis (TEA) models are developed for a tertiary wastewater treatment system that employs a biochar-integrated reactive filtration (RF) approach. This innovative system incorporates the utilization of biochar (BC) either in conjunction with or independently of iron-ozone catalytic oxidation (CatOx)-resulting in two configurations: Fe-CatOx-BC-RF and BC-RF. The technology demonstrates 90%-99% total phosphorus removals, adsorption of phosphorus to biochar for recovery, and >90% destructive removal of observed micropollutants. In this work, we conduct an ISO-compliant LCA of a 49.2 m3 /day (9 gpm) field pilot-scale Fe-CatOx-BC-RF system and a 1130 m3 /day (0.3 MGD) water resource recovery facility (WRRF)-installed RF system, modeled with BC addition at the same rate of 0.45 g/L to quantify their environmental impacts. LCA results indicated that the Fe-CatOx-BC-RF pilot system is a BC dose-dependent carbon-negative technology at -1.21 kg CO2 e/m3 , where biochar addition constitutes a -1.53 kg/m3 CO2 e beneficial impact to the process. For the WRRF-installed RF system, modeled with the same rate of BC addition, the overall process changed from 0.02 kg CO2 e/m3 to a carbon negative -1.41 kg CO2 e/m3 , demonstrating potential as a biochar dose-dependent negative emissions technology. Using the C100 100-year carbon accounting approach rather than Cnet reduces these CO2 e metrics for the process by about 25%. A stochastic TEA for the cost of water treatment using this combinatorial P removal/recovery, micropollutant destructive removal, and disinfection advanced technology shows that at scale, the mean cost for treating 1130 m3 /day (0.3 MGD) WRRF secondary influent water with Fe-CatOx-BC-RF using the C100 metric is US$0.18 ± US$0.01/m3 to achieve overall process carbon neutrality. Using the same BC dose in an estimation of a 3780 m3 /day (1 MGD) Fe-CatOx-BC-RF facility, the carbon neutral cost of treatment is reduced further to US$0.08 ± $0.01 with added BC accounting for US$0.03/m3 . Overall, the results demonstrate the potential of carbon negativity to become a water treatment performance standard as important and attainable as pollutant and pathogen removal. PRACTITIONER POINTS: Life cycle assessment (LCA) of a pilot scale tertiary biochar water treatment process with or without catalytic ozonation at a WRRF shows a carbon negative global warming potential of -1.21-kg CO2e/m3 while removing 90%-99% TP and >90% of detected micropollutants. Biochar-integrated reactive filtration use can aid in long-term carbon sequestration by reducing the carbon footprint of advanced water treatment in a dose-dependent manner, allowing an overall carbon-neutral or carbon-negative process. A companion paper to this work (Yu et al., 2023) presents the details related to the process operation and mechanism and evaluates the pollutant removal performance of this Fe-CatOx-BC-RF process in engineering laboratory pilot research and field WRRF pilot-scale water resource recovery trials. Techno-economic analysis (TEA) of this biochar catalytic oxidation reactive filtration process using Monte Carlo stochastic modeling shows a forecasted carbon-neutral process cost with low P and micropollutant removal as US$0.11/m3 ± 0.01 for a 3780-m3/day (1 MGD) scale installation with BC cost at US$0.03/m3 of that total. The results demonstrate the potential of carbon negativity to become a water treatmentperformance standard as important and attainable as pollutant and pathogen removal.

Life Cycle Assessment in a Nutshell-Best Practices and Status Quo for the Plastic Sector

Life cycle assessment (LCA) is an internationally standardized methodology to evaluate the potential environmental impacts of products and technologies and assists in lowering their negative environmental consequences. So far, extensive knowledge of LCA-their application and interpretation-is restricted to experts. However, the importance of LCA is increasing due to its application in business, environmental, and policy decision-making processes. Therefore, general knowledge of LCA is critically important. The current work provides an introduction to LCA for non-experts discussing important steps and aspects and therefore can be used as a starting point for LCA. In addition, a comprehensive checklist for non-experts with important content and formal aspects of LCA is provided. Specific aspects of LCA for the plastics sector along the value chain are also discussed, including their limitations.

Environmental Life Cycle Assessment of a Novel Hemp-Based Building Material

The global construction sector contributes a significant share of total greenhouse gas (GHG) emissions. In Australia, infrastructure activity alone generates 18% of the GHG emissions. The use of low-embodied carbon building materials is crucial to decarbonise the construction sector and fulfil national and international climate goals. Industrial hemp (Cannabis sativa L.) is a promising feedstock for low-carbon construction materials because of its carbon sequestration capacity, fast-growing cycles, and technical functionality comparable to traditional materials. This study utilised the life cycle assessment (LCA) guideline ISO 14040:2006 to estimate the carbon footprint (CF) of hemp-based building materials in Western Australia capturing region-specific variations in terms of inputs, soil, productivity, and energy mix. The functional unit was 1 m2 of a hemp-based board, and the system boundary was cradle-to-gate, i.e., pre-farm, on-farm, and post-farm activities. The CF of 1 m2 of hemp-based board was estimated to be -2.302 kg CO2 eq. Electricity from the public grid for bio-based binder production during the post-farm stage was the main contributor to total CO2 eq emissions (26%), followed by urea production (14%) during the pre-farm stage. Overall, the use of electricity from the public grid during the post-farm stage accounted for 45% of total emissions. Sensitivity analysis showed that the CF of hemp-based boards was highly sensitive to the source of energy; i.e., total replacement of the public grid by solar power decreased the CF by 164% (-2.30 to -6.07 kg CO2 eq). The results suggested that hemp-based boards exhibit lower embodied GHG emissions compared to traditional materials, such as gypsum plasterboards.

Transition Metal Catalysts for Atmospheric Heavy Metal Removal: A Review of Current Innovations and Advances

Atmospheric heavy metal pollution presents a severe threat to public health and environmental stability. Transition metal catalysts have emerged as a potent solution for the selective capture and removal of these pollutants. This review provides a comprehensive summary of current advancements in the field, emphasizing the efficiency and specificity of nanostructured transition metals, including manganese, iron, cobalt, nickel, copper, and zinc. Looking forward, we delve into the prospective trajectory of catalyst development, underscoring the need for materials with enhanced stability, regenerability, and environmental compatibility. We project that advancements in computational materials science, nanotechnology, and green chemistry will be pivotal in discovering innovative catalysts that are economically and environmentally sustainable. The integration of smart technologies for real-time monitoring and adaptive control is anticipated to revolutionize heavy metal remediation, ensuring efficient and responsive pollution abatement strategies in the face of evolving industrial scenarios and regulatory landscapes.

Anaerobic Wastewater Treatment and Potable Reuse: Energy and Life Cycle Considerations

Anaerobic secondary treatment has the potential to facilitate energy-positive operations at wastewater treatment plants, but post-treatment of the anaerobic effluent is needed to recover dissolved methane and nutrients and remove sulfide. In this study, a life cycle assessment was conducted to compare hypothetical full-scale wastewater treatment trains and direct potable reuse trains that combine the staged anaerobic fluidized membrane bioreactor (SAF-MBR) with appropriate post-treatment. We found that anaerobic wastewater treatment trains typically consumed less energy than conventional aerobic treatment, but overall global warming potentials were not significantly different. Generally, recovery of dissolved methane for energy production resulted in lower life cycle impacts than microbial transformation of methane, and microbial oxidation of sulfide resulted in lower environmental impacts than chemical precipitation. Use of reverse osmosis to produce potable water was also found to be a sustainable method for nutrient removal because direct potable reuse trains with the SAF-MBR consumed less energy and had lower life cycle impacts than activated sludge. Moving forward, dissolved methane recovery, reduced chemical usage, and investments that enable direct potable reuse have been flagged as key research areas for further investigation of anaerobic secondary treatment options.

Evaluating Nitrogen Management Practices for Greenhouse Gas Emission Reduction in a Maize Farmland in the North China Plain: Adapting to Climate Change

Quantification of the trade-offs among greenhouse gas (GHG) emissions, yield, and farmers' incomes is essential for proposing economic and environmental nitrogen (N) management strategies for optimizing agricultural production. A four-year (2017-2020) field experiment (including four treatments: basic N fertilizer treatment (BF), suitable utilization of fertilization (SU), emission reduction treatment (ER), and high fertilization (HF)) was conducted on maize (Zea mays L.) in the North China Plain. The Life Cycle Assessment (LCA) method was used in this study to quantify the GHG emissions and farmers' incomes during the whole maize production process. The total GHG emissions of BF, SU, ER, and HF treatments in the process of maize production are 10,755.2, 12,908.7, 11,950.1, and 14,274.5 kg CO2-eq ha-1, respectively, of which the direct emissions account for 84.8%, 76.8%, 74.9%, and 71.0%, respectively. Adding inhibitors significantly reduced direct GHG emissions, and the N2O and CO2 emissions from the maize fields in the ER treatment decreased by 30.0% and 7.9% compared to those in the SU treatment. Insignificant differences in yield were found between the SU and ER treatments, indicating that adding fertilizer inhibitors did not affect farmers' incomes while reducing GHG emissions. The yield for SU, ER, and HF treatments all significantly increased by 12.9-24.0%, 10.0-20.7%, and 2.1-17.4% compared to BF, respectively. In comparison with BF, both SU and ER significantly promoted agricultural net profit (ANP) by 16.6% and 12.2%, with mean ANP values of 3101.0 USD ha-1 and 2980.0 USD ha-1, respectively. Due to the high agricultural inputs, the ANP values in the HF treatment were 11.2%, 16.6%, and 12.4% lower than those in the SU treatment in 2018-2020. In conclusion, the combination of N fertilizer and inhibitors proved to be an environmentally friendly, high-profit, and low-emissions production technology while sustaining or even increasing maize yields in the North China Plain, which was conducive to achieving agricultural sustainability.

Estimating the environmental impacts of global lithium-ion battery supply chain: A temporal, geographical, and technological perspective

A sustainable low-carbon transition via electric vehicles will require a comprehensive understanding of lithium-ion batteries' global supply chain environmental impacts. Here, we analyze the cradle-to-gate energy use and greenhouse gas emissions of current and future nickel-manganese-cobalt and lithium-iron-phosphate battery technologies. We consider existing battery supply chains and future electricity grid decarbonization prospects for countries involved in material mining and battery production. Currently, around two-thirds of the total global emissions associated with battery production are highly concentrated in three countries as follows: China (45%), Indonesia (13%), and Australia (9%). On a unit basis, projected electricity grid decarbonization could reduce emissions of future battery production by up to 38% by 2050. An aggressive electric vehicle uptake scenario could result in cumulative emissions of 8.1 GtCO2eq by 2050 due to the manufacturing of nickel-based chemistries. However, a switch to lithium iron phosphate-based chemistry could enable emission savings of about 1.5 GtCO2eq. Secondary materials, via recycling, can help reduce primary supply requirements and alleviate the environmental burdens associated with the extraction and processing of materials from primary sources, where direct recycling offers the lowest impacts, followed by hydrometallurgical and pyrometallurgical, reducing greenhouse gas emissions by 61, 51, and 17%, respectively. This study can inform global and regional clean energy strategies to boost technology innovations, decarbonize the electricity grid, and optimize the global supply chain toward a net-zero future.

Circularizing PET-G Multimaterials: Life Cycle Assessment and Techno-Economic Analysis

The recycling of multimaterials such as payment or access cards poses significant challenges. Building on previous experimental work demonstrating the feasibility of chemically recyclable payment cards made from glycol-modified poly(ethylene terephthalate) (PET-G), we use life cycle assessment and techno-economic analysis to investigate two chemical recycling scenarios and evaluate their potential environmental and economic benefits. Recovering all components from the depolymerized products (Scenario 1) achieves substantial environmental benefits across most categories, reducing global warming by up to 67% compared to only recovering major components (Scenario 2). However, the environmental benefits in Scenario 1 incur 69% higher total annualized costs, causing its profitability to be dependent on a minimum selling price of £13.4/kg for cyclohexanedimethanol and less than a 10% discount rate. In contrast, Scenario 2 is less sensitive to discount rate variation and thus a lower risk and more economically feasible option, albeit less environmentally sustainable.

The Relevance of Life Cycle Assessment Tools in the Development of Emerging Decarbonization Technologies

The development of emerging decarbonization technologies requires advanced tools for decision-making that incorporate the environmental perspective from the early design. Today, Life Cycle Assessment (LCA) is the preferred tool to promote sustainability in the technology development, identifying environmental challenges and opportunities and defining the final implementation pathways. So far, most environmental studies related to decarbonization emerging solutions are still limited to midpoint metrics, mainly the carbon footprint, with global sustainability implications being relatively unexplored. In this sense, the Planetary Boundaries (PBs) have been recently proposed to identify the distance to the ideal reference state. Hence, PB-LCA methodology can be currently applied to transform the resource use and emissions to changes in the values of PB control variables. This study shows a complete picture of the LCA's role in developing emerging technologies. For this purpose, a case study based on the electrochemical conversion of CO2 to formic acid is used to show the possibilities of LCA approaches highlighting the potential pitfalls when going beyond greenhouse gas emission reduction and obtaining the absolute sustainability level in terms of four PBs.

A Critical Review of Data Science Applications in Resource Recovery and Carbon Capture from Organic Waste

Municipal and agricultural organic waste can be treated to recover energy, nutrients, and carbon through resource recovery and carbon capture (RRCC) technologies such as anaerobic digestion, struvite precipitation, and pyrolysis. Data science could benefit such technologies by improving their efficiency through data-driven process modeling along with reducing environmental and economic burdens via life cycle assessment (LCA) and techno-economic analysis (TEA), respectively. We critically reviewed 616 peer-reviewed articles on the use of data science in RRCC published during 2002-2022. Although applications of machine learning (ML) methods have drastically increased over time for modeling RRCC technologies, the reviewed studies exhibited significant knowledge gaps at various model development stages. In terms of sustainability, an increasing number of studies included LCA with TEA to quantify both environmental and economic impacts of RRCC. Integration of ML methods with LCA and TEA has the potential to cost-effectively investigate the trade-off between efficiency and sustainability of RRCC, although the literature lacked such integration of techniques. Therefore, we propose an integrated data science framework to inform efficient and sustainable RRCC from organic waste based on the review. Overall, the findings from this review can inform practitioners about the effective utilization of various data science methods for real-world implementation of RRCC technologies.

Life Cycle Assessment of Production of Hydrochar via Hydrothermal Carbonization of Date Palm Fronds Biomass

This study presents novel life cycle assessment (LCA) findings on hydrochar production from Saudi-Arabia-based date palm fronds biomass waste using hydrothermal carbonization (HTC). The LCA procedure incorporated normalization, weighting, and improvement assessment. The system boundary encompassed water consumption and energy requirements within a lab setting representing a gate-to-gate process. The OpenLCA 1.11.0 software with the European Life Cycle Database 3.2 (ELCD 3.2) was utilized for the study and we employed the ReCiPe Midpoint (H) 2016 and Environmental Footprint 3.0 (EF 3.0) impact assessment methods. The results indicated that fossil fuel usage represented the most significant impact category with the HTC and drying processes identified as major contributors. It was also observed that the HTC process exerted far greater detrimental impacts on the environment than the biomass grinding process. The overwhelming impact of fossil fuel resources could be mitigated by optimizing the batches of biomass or hydrochar samples in each operation, which could alleviate fossil fuel consumption by up to 94%. The findings emphasize the need for targeted interventions to mitigate the environmental burden and contribute to sustainable hydrochar production.

[Effects of Straw Biochar on Carbon Footprint of Maize Farmland Ecosystem Under Mulched Drip Irrigation in Hetao Irrigation District]

To explore the effect of biochar on greenhouse gas emissions and the carbon footprint of a corn farmland ecosystem under drip irrigation with film in an arid region, biochar treatments with different application rates[0 (CK), 15 (C15), 30 (C30), and 45 t·hm-2 (C45)] were established. The seasonal changes in soil greenhouse gases (CO2, N2O, and CH4) and their comprehensive warming potential in the maize farmland ecosystem were monitored for two consecutive years after a one-time application of biochar. The carbon emissions caused by agricultural production activities and their carbon footprint were estimated using the life cycle assessment method. Compared with that in CK, the cumulative CO2 emissions in the crop growing season decreased by 17.6%-24.7%, the cumulative N2O emissions decreased by 71.1%-110.4%, and the global warming potential decreased by 19.5%-25.9%. In the second year of the crop growing season after biochar application, the cumulative CO2 emissions were reduced by 19.2%-40.6%, the cumulative N2O emissions were reduced by 38.7-46.7%, and the comprehensive warming potential was reduced by 19.7%-40.5%. For two consecutive years, the treatment of C15 and C30 increased the cumulative absorption of CH4 to different degrees, whereas the treatment of C45 significantly decreased the cumulative absorption of CH4. C15 and C45 were the treatments with the least carbon footprint per unit yield in the current and the succeeding year of biochar application, and their carbon footprint per unit yield was 10.1% and 26.2% lower than that of CK, respectively. Soil greenhouse gas emissions showed the most contribution to the carbon footprint of the maize farmland ecosystem (38.1%-59.2%), followed by nitrogen fertilizer production (19.8%-33.4%), electric energy production (6.7%-8.8%), and plastic film mulching (4.4%-7.4%). Biochar contributed 5.7%-13.8% to the ecosystem's carbon footprint. The application of 30 t·hm-2 biochar had a better effect on carbon reduction, carbon fixation, and yield increase in the farmland ecosystem. Improving the biochar production process and transportation route, increasing nitrogen use efficiency, and developing water-saving and energy-saving irrigation technology are important ways to reduce the carbon footprint of farmland ecosystems in arid regions.

Comparative Life Cycle Assessment (LCA) of Porous Asphalt Mixtures with Sustainable and Recycled Materials: A Cradle-to-Gate Approach

The road and construction sectors consume a large number of natural resources and energy, contributing significantly to waste generation and greenhouse gas emissions (GHG). The use of recycled aggregate from construction and demolition waste as a substitute for virgin aggregate is a current practice in the construction of new road sections. Additionally, in recent years, there has been an increasing focus on finding alternatives to bitumen for binders used in asphalt mixes. This study investigates and compares the impacts associated with two porous asphalt mixtures produced with CDW aggregates, virgin aggregates, and a polyolefin-based synthetic transparent binder through an LCA methodology. A cradle-to-gate approach was employed. Model characterization for calculating the potential environmental impacts of each porous asphalt mixture was performed using the ReCipe 2016 assessment method at the midpoint and endpoint levels. The results are presented with reference to a baseline scenario corresponding to a porous asphalt mixture, confirming the benefits associated with the use of recycled aggregates and in some cases the benefits of not using bitumen-based binders. This work contributes to the understanding of the importance of choosing the least environmentally damaging solution during the production or rehabilitation of road pavement infrastructure.

Economic and environmental assessment of U.S. broiler production: opportunities to improve sustainability

The United States is the largest broiler producer in the world, and Americans consume about 45 kg of chicken per capita per year, which generates substantial economic and environmental footprints. We conduct techno-economic analysis and life cycle assessment (TEA/LCA) to evaluate the sustainability performance of the U.S. broiler industry and quantify the cost, greenhouse gas (GHG) emissions, energy, water, land, fertilizer, and respiratory impacts of 7 broiler production scenarios for a contract Grower, Integrator, and Combined control volume. The assessment is a farm-gate to farm-gate analysis that includes capital cost of chicken houses, labor, chicks brought into the farm, feeds, on-site fuels, and on-site emissions. We found that economics for the Integrator are profitable and dominated by the cost of corn and soybean meal feeds, payments to the Grower, and revenue from live broilers. Additionally, we found that economics for the Grower generate modest return on investment (ROI) largely based on the cost of houses and labor when compared to contract revenue from the Integrator. Environmental impacts for GHG, energy, and respiratory effects are primarily associated with upstream feed production (roughly 65%-80% of total impacts) and on-site fuel consumption (∼20%-35% of total impacts), while those for water, land, and eutrophication are almost entirely attributable to upstream feed production (litter spreading has a low economic allocation factor). Tradeoffs among sustainability metrics are further explored with a sensitivity analysis and by evaluating cost/environmental benefit scenarios.

Parametric Life Cycle Assessment of Nuclear Power for Simplified Models

Electrifying the global economy is accepted as a main decarbonization lever to reach the Paris Agreement targets. The IEA's 2050 Net Zero transition pathways all involve some degree of nuclear power, highlighting its potential as a low-carbon electricity source. Greenhouse gas emissions of nuclear power reported in the life cycle assessment literature vary widely, from a few grams of CO2 equivalents to more than 100 g/kWh, globally. The reasons for such a variation are often misunderstood when reported and used by policymakers. To fill this gap, one can make LCA models explicit, exploring the role of the most significant parameters, and develop simplified models for the scientific community, policymakers, and the public. We developed a parametric cradle-to-grave life cycle model with 20 potentially significant variables: ore grade, extraction technique, enrichment technique, and power plant construction requirements, among others. Average GHG emissions of global nuclear power in 2020 are found to be 6.1 g CO2 equiv/kWh, whereas pessimistic and optimistic scenarios provide extreme values of 5.4-122 g CO2 equiv/kWh. We also provide simplified models, one per environmental impact indicator, which can be used to estimate environmental impacts of electricity generated by a pressurized water reactor without running the full-scale model.