Ozone Depletion Research Articles

Bio-fumigants as grain protectants in storage-A review

Agriculture is a global lifeline, especially in developing nations like India, where over 70% of the population relies on it. Protecting food grains from insect pests during post-harvest storage is crucial, particularly in regions lacking advanced storage technologies, leading to significant losses. Fumigation is still a key strategy for safeguarding stored grains. Methyl bromide (MBr) and aluminium phosphide (AlP) are the widely used chemical fumigants. Phosphine is used to a greater extent today, but there are frequent reports that several storage pests have developed resistance to this fumigant. The United Nations World Meteorological Organization declared methyl bromide as an ozone-depleting chemical in 1995, and hence, most of the developed countries have phased out its use. Therefore, there is an urgent requirement to develop alternatives having a possible replacement for these fumigants. Biofumigants are organic compounds derived from various plant sources, including essential oils, botanical powders, and plant residues or from microbial volatiles. They release volatile compounds toxic to pests but safe for humans and the environment, offering a sustainable pest management approach. Plants such as mustard and radish produce glucosinolates that release isothiocyanates, known for their pesticidal properties. Essential oils from eucalyptus, clove, and mint and volatiles from certain fungi and bacteria also exhibit fumigant properties. Biofumigants disrupt insect physiological and biochemical processes, leading to mortality or reduced reproduction. Studies showed their efficacy against pests like red flour beetle, lesser grain borer, and rice weevil. Unlike chemical fumigants, biofumigants do not leave harmful residues, preserving grain quality and aligning with organic farming practices. Shifting to biofumigants offers a promising, eco-friendly, and effective alternative for post-harvest pest management, ensuring food safety and sustainability

Canada and the United Nations: Setting the Record Straight

In response to the 2023 report, “Canada and the United Nations: Rethinking and Rebuilding Canada's Global Role,” Jack Cunningham argues that Canada should instead marginalize the United Nations. In response, this rejoinder maintains that, while the UN has weaknesses, the world would be a worse place without it. Look to the UN's work to close the hole in the ozone layer, deliver life-saving vaccines to millions, or give food and shelter to the displaced. The UN has been a remarkably successful norm-setter, creating vital international standards on issues that range from the more political to the technical. Cunningham favours a retreat by Canada to smaller clubs of like-minded states, without explaining how this retrenchment might produce more effective results on global issues, such as climate change. He offers no alternative to the UN. It is hard to see how abandoning the field to China, Russia, and Iran, would serve Canada's interests.

Antarctic extreme seasons under 20th and 21st century climate change

In this study, available large ensemble datasets in the Coupled Model Intercomparison Phase 6 (CMIP6) archive were used to provide the first multi-variate overview of the evolution of extreme seasons over Antarctica and the Southern Ocean during the 20th and 21st centuries following medium-to-high radiative forcing scenarios. The results show significant differences between simulated changes in background mean climate and changes in low (10th percentile) and high (90th percentile) extreme seasons. Regional winter warming is most pronounced for cold extremes. In summer, there are more pronounced increases in high extremes in precipitation and westerly wind during the ozone hole formation period (late 20th century), affecting coastal regions and, in particular, the Antarctic Peninsula. At midlatitudes, there is a reduction in the range of summer season wind extremes. Suggested mechanisms for these differences are provided relating to sea ice retreat and westerly jet position.

A fully coupled solid-particle microphysics scheme for stratospheric aerosol injections within the aerosol–chemistry–climate model SOCOL-AERv2

Abstract. Recent studies have suggested that injection of solid particles such as alumina and calcite particles for stratospheric aerosol injection (SAI) instead of sulfur-based injections could reduce some of the adverse side effects of SAI such as ozone depletion and stratospheric heating. Here, we present a version of the global aerosol–chemistry–climate model SOCOL-AERv2 and the Earth system model (ESM) SOCOLv4 which incorporate a solid-particle microphysics scheme for assessment of SAI of solid particles. Microphysical interactions of the solid particle with the stratospheric sulfur cycle were interactively coupled to the heterogeneous chemistry scheme and the radiative transfer code (RTC) for the first time within an ESM. Therefore, the model allows simulation of heterogeneous chemistry at the particle surface as well as feedbacks between microphysics, chemistry, radiation and climate. We show that sulfur-based SAI results in a doubling of the stratospheric aerosol burden compared to the same mass injection rate of calcite and alumina particles with a radius of 240 nm. Most of the sulfuric acid aerosol mass resulting from SO2 injection does not need to be lifted to the stratosphere but is formed after in situ oxidation and subsequent water uptake in the stratosphere. Therefore, to achieve the same radiative forcing, larger injection rates are needed for calcite and alumina particle injection than for sulfur-based SAI. The stratospheric sulfur cycle would be significantly perturbed, with a reduction in stratospheric sulfuric acid burden by 53 %, when injecting 5 Mt yr−1 (megatons per year) of alumina or calcite particles of 240 nm radius. We show that alumina particles will acquire a sulfuric acid coating equivalent to about 10 nm thickness if the sulfuric acid is equally distributed over the whole available particle surface area in the lower stratosphere. However, due to the steep contact angle of sulfuric acid on alumina particles, the sulfuric acid coating would likely not cover the entire alumina surface, which would result in available surface for heterogeneous reactions other than the ones on sulfuric acid. When applying realistic uptake coefficients of 1.0, 10−5 and 10−4 for H2SO4, HCl and HNO3, respectively, the same scenario with injections of calcite particles results in 94 % of the particle mass remaining in the form of CaCO3. This likely keeps the optical properties of the calcite particles intact but could significantly alter the heterogeneous reactions occurring on the particle surfaces. The major process uncertainties of solid-particle SAI are (1) the solid-particle microphysics in the injection plume and degree of agglomeration of solid particles on the sub-ESM grid scale, (2) the scattering properties of the resulting agglomerates, (3) heterogeneous chemistry on the particle surface, and (4) aerosol–cloud interactions. These uncertainties can only be addressed with extensive, coordinated experimental and modelling research efforts. The model presented in this work offers a useful tool for sensitivity studies and incorporating new experimental results on SAI of solid particles.

Pharmaceutical, Clinical, and Regulatory Challenges of Reformulating Pressurized Metered-Dose Inhalers to Reduce Their Environmental Impact.

The chlorofluorocarbons (CFCs) that were used as propellants in early pressurized metered-dose inhalers (pMDIs) had substantial ozone-depleting potential. Following the Montreal Protocol in 1987, the manufacture of a range of ozone-depleting substances, including CFCs, was gradually phased out, which required the propellants used in pMDIs to be replaced. Current pMDIs use hydrofluoroalkanes (HFAs) as propellants, such as 1,1,1,2-tetrafluoroethane (HFA-134a). Although these HFAs have no ozone-depleting potential, they have a high global warming potential (GWP), and consequently, their use is being phased down. One option for the discontinuation of HFA use in inhalers would be to discontinue all pMDIs, switching patients to dry powder inhalers (DPIs). However, a switch from pMDIs to DPIs may not be a clinically appropriate option for some patients; furthermore, the full lifecycle carbon footprint and the overall environmental impact of different inhalers should be considered. An alternative is therefore to reformulate the current HFA pMDIs to use low-GWP propellants, such as 1,1-difluoroethane (HFA-152a). This article summarizes the various steps and challenges associated with this change, illustrated using data from the inhaled triple combination of beclomethasone dipropionate, formoterol fumarate, and glycopyrronium bromide, a complex formulation of three molecules in a solution that contains liquid-phase propellant.

Physicochemical perturbation increases nitrous oxide production from denitrification in soils and sediments

Abstract. Atmospheric concentrations of nitrous oxide (N2O), a potent greenhouse gas that is also responsible for significant stratospheric ozone depletion, have increased in response to the intensified use of agricultural fertilizers and other human activities that have accelerated nitrogen cycling processes. Microbial denitrification in soils and sediments is a major source of N2O, produced as an intermediate during the reduction of oxidized forms of nitrogen to dinitrogen gas (N2). Substrate availability (nitrate and organic matter) and environmental factors such as oxygen levels, temperature, moisture, and pH influence rates of denitrification and N2O production. Here we describe the role of physicochemical perturbation (defined here as a change from the ambient environmental conditions) in influencing rates of denitrification and N2O production. Changes in salinity, temperature, moisture, pH, and zinc in agricultural soils induced a short-term perturbation response characterized by lower rates of total denitrification and higher rates of net N2O production. The ratio of N2O to total denitrification (N2O : DNF) increased strongly with physicochemical perturbation. A salinity press experiment on tidal freshwater marsh soils revealed that increased N2O production was likely driven by transcriptional inhibition of the nitrous oxide reductase (nos) gene and that the microbial community adapted to altered salinity over a relatively short time frame (within 1 month). Perturbation appeared to confer resilience to subsequent disturbance, and denitrifiers from an environment without salinity fluctuations (tidal freshwater estuarine sediments) demonstrated a stronger N2O perturbation response than denitrifiers from environments with more variable salinity (oligohaline and mesohaline estuarine sediments), suggesting that the denitrifying community from physicochemically stable environments may have a stronger perturbation response. These findings provide a framework for improving our understanding of the dynamic nature of N2O production in soils and sediments, in which changes in physical and/or chemical conditions initiate a short-term perturbation response that promotes N2O production that moderates over time and with subsequent physicochemical perturbation.

A Comparative Analysis of the Environmental Impacts of Wood–Aluminum Window Production in Two Life Cycle Assessment Software

In the construction sector, there is a shift towards environmentally conscious practices that prioritize the minimization of environmental burdens. In this study, we dealt with a cradle-to-gate life cycle assessment (LCA) of a wood–aluminum window in two software tools. SimaPro (PRé Sustainability) and Sphera LCA for Experts (formerly known as GaBi) were selected. The results from both software tools were compared to assess the output uniformity of the two selected tools. The results indicate the similarities and differences in the software tools. The most similar results were achieved for impact categories Photochemical Ozone Formation (1.1% difference), Human Toxicity, cancer (total) (3.6% difference), Climate Change (3.7% difference) and for Resource Use, fossils (4.5% difference), respectively. On the other hand, the results were most different in the impact categories Ozone Depletion (84.7% difference), Resource Use, minerals and metals (75% difference), Ecotoxicity, freshwater—inorganics (35.6%) and Ecotoxicity, freshwater (total) (31.2%), respectively. The differences in the LCA results between SimaPro and GaBi were analyzed in-depth and were mainly attributable to using different databases in the transportation process and due to different system boundaries in some processes, with the Ecoinvent data containing significantly more background processes and inconsistencies in the implemented characterization factors.

Consequential life cycle assessment of urban source-separating sanitation systems complementing centralized wastewater treatment in Lund, Sweden

This study examined various source-separating sanitation systems to evaluate their environmental performance, providing decision-makers with insights for selecting an appropriate system for a newly developed neighborhood in Sweden. A full consequential LCA was conducted to account for resource recovery and substitution. The local wastewater treatment plant WWTP was modeled as a reference. Secondly, a urine recycling system was introduced to treat 75% of the collected urine, with the remainder piped to the WWTP. Thirdly, a black and greywater (BW&GW) treatment system handling all generated wastewater was examined. Finally, a hybrid source-separating system combining urine, black, and greywater was investigated. The results indicated that the four scenarios exhibited global warming potentials (GWP) of 78, 62, 32, and 24 kg CO2-eq per PE/ y. Recycling urine as fertilizer led to a 20% reduction in the GWP of the reference. It also reduced other impact categories, with a 55%, 65%, and 45% reduction in eutrophication, ozone depletion, and acidification, respectively. The BW&GW system achieved a 60% reduction over the reference GWP, mainly due to fertilizer, biogas, and cleanwater recovery. Integrating urine, black, and greywater recycling in the final scenario achieved a 25% reduction compared to the BW&GW scenario, primarily due to lowering of the ammonia stripping GWP and the additional fertilizer recovery. Based on sensitivity analyses, switching citric acid for sulfuric acid reduced the GWP of the urine stabilization unit process by 101%, from 15.47 to -0.14 kg CO2-eq per PE/ y. Ultimately, the findings suggest that the fully decentralized source-separating sanitation system incorporating urine, blackwater, and greywater recycling, particularly when combined with 70% energy recovery at the urine concentrator, is most favorable.

Reductions in atmospheric levels of non-CO2 greenhouse gases explain about a quarter of the 1998-2012 warming slowdown

The observed global mean surface temperature increase from 1998 to 2012 was slower than that since 1951. The relative contributions of all relevant factors including climate forcers, however, have not been comprehensively analyzed. Using a reduced-complexity climate model and an observationally constrained statistical model, here we find that La Niña cooling and a descending solar cycle contributed approximately 50% and 26% of the total warming slowdown during 1998-2012 compared to 1951-2012. Furthermore, reduced ozone-depleting substances and methane accounted for roughly a quarter of the total warming slowdown, which can be explained by changes in atmospheric concentrations. We identify that non-CO2 greenhouse gases played an important role in slowing global warming during 1998-2012.

Investigating the environmental impacts of lithium-oxygen battery cathode production: A comprehensive assessment of the effects associated with oxygen cathode manufacturing

Lithium-oxygen batteries offer remarkably high energy density compared to current lithium-ion batteries. The key to their electrochemical performance lies in the processes occurring at the air cathode. However, the complexity of these reactions, coupled with the by-products generated during discharge, can make the reaction process slow or impede their efficiency. This study evaluates the environmental impact of high-efficiency lithium-oxygen batteries cathodes, including titanium oxide composites, graphene-based composites and activated carbon-based composites, through a life cycle assessment across 18 impact categories using a cradle-to-gate approach with a functional unit of 25 kWh. Results show that active material production was the largest contributor to environmental impact, particularly Global Warming Potential. Among the evaluated cathodes, reduced graphene oxide/α-mnaganese oxide/palladium (rGO/α-MnO2/Pd) demonstrated the highest environmental impact, with a global warming potential of 1130.71 kg carbon dioxide from active material production, due to its energy-intensive synthesis and the use of chemicals like sulfuric acid, sodium borohydride, hydrochloric acid, and hydrogen peroxide. Additionally, the rGO/α-MnO2/Pd cathode had the highest Human Toxicity Potential and Ozone Depletion Potential. Batteries with graphene-based cathodes achieved a specific capacity of 7500 mAh.g-1, underscoring their performance potential while highlighting the need for more sustainable cathode manufacturing methods. These findings emphasize the environmental considerations necessary for large-scale lithium-oxygen batteries implementation.

THE ROLE OF INFORMATION TECHNOLOGY IN ENSURING ENVIRONMENTAL WELLNESS IN DEVELOPING COUNTRIES

In recent years, the world has witnessed the introduction of several new information technologies (IT) that have significantly contributed to the safety of our environment. Ozone Layer depletion and other environmental hazards have given man serious concern most especially in developing countries. This paper therefore examines the contributions of IT to environmental safety in developing countries. It adopted a survey research design approach and use five Likert scale questionnaire with 15 items drawn from three research questions to collect quantitative data. SPSS was used to compute the mean and standard deviation of the responses from the respondents. The result shows that digital closed circuit television is one of the powerful IT devices that can be used to ensure environmental safety. Other information technology devices such as wearables technology, Internet of Thing, weather forecasting application and so on are of tremendous benefit to environmental wellness in many form. The study also reveal that the developing nations can benefit greatly if they invest on making Information Technology available and accessible to all citizen. It emphasizes the use of renewable energy to power those devices for maximum performance..

Design, optimization, and performance analysis of a solar-wind powered compression chiller with built-in energy storage system for sustainable cooling in remote areas

This study aims to develop a sustainable cooling solution for refrigeration in remote areas, utilizing solely wind and solar power. Ensuring that the power generated aligns with consumption throughout the day is a critical challenge. The investigation centers on the integration of an energy storage and a compression cooling cycle to attain the desired objective. This system integrates refrigerant storage on both the evaporator and condenser sides. The storage tanks' volume is variable by time and should be adjusted automatically. The sustainability of the cooling capacity depends on the amount of input power and the type of refrigerant. Moreover, additional heat is extracted to produce hot water. The analysis includes the coefficient of performance, exergy efficiency, cooling capacity, total heating capacity, and environmental impacts for six refrigerants R134a, R22, R717, R125, R500, and R407c. The system is configured to offer a cooling capacity of 15 kW while maintaining a temperature difference of 38K. The best performance is achieved using R717 as the refrigerant with a coefficient of performance of 5.26, an exergy efficiency of 36 %, and a payback period of 2.267 in Sabzevar. Furthermore, R717 does not contribute to ozone depletion or global warming.

Sustainability challenges and solutions in medical laboratory equipment manufacturing

Background: Ultra-low temperature (ULT) freezers are vital for storing biological samples in medical labs, but they have high energy demands and significant environmental impacts. This study investigates the energy efficiency, environmental footprint, and performance of different ULT freezer models. Methodology: A lifecycle assessment (LCA) was performed on five ULT freezers to evaluate global warming potential (GWP), ozone depletion potential (ODP), and energy consumption. Key performance metrics, including compressor efficiency, thermal stability, and material recyclability, were assessed under various operating conditions. Real-time data was collected over 30 days. Results: Freezers with variable-speed compressors exhibited up to 25% lower energy consumption than those with fixed-speed systems. Freezers using low-GWP refrigerants, such as CO₂, reduced total CO₂ emissions by up to 30% over a 10-year lifespan. Models incorporating advanced insulation materials, like vacuum-insulated panels (VIPs), showed improved thermal stability and reduced heat rejection, leading to lower cooling loads. Conclusion: Adopting advanced compressor technologies, low-GWP refrigerants, and high-performance insulation materials in ULT freezers can significantly reduce energy use and environmental impact. These innovations are crucial for sustainable medical laboratory operations, balancing performance with environmental responsibility.

The Research on Factors Influencing Air Pollution

The rapid development of urbanization contributes to that the people’ life is more and more beautiful and their quality of life is better and better. There are a lot of complex and diversity influencing of air pollutants. This paper finds a lot of articles and reports of government and focus on four air pollutants: carbon monoxide, ozone, nitrogen oxides, and particulate matter, including ultra-fine particles. Air pollution can cause three major environmental problems, including greenhouse effect, acid rain, and ozone hole, which can cause significant damage to the lungs and respiratory tract of the human body, such as chronic lung disease, neurological damage, and heart disease. The purpose of the article is to find some factors that affect air pollution. Using the method of multiple linear regression turns out that there is a significant linear regression relationship between human activities, exhaust emissions from vehicles, ships, airplanes, industrial pollutant, meteorological conditions, landform and PM2.5, while the speed and direction of wind fail the important test.

Climate Change, Air Pollution, African Dust Impacts on Public Health and Sustainability in Europe

Abstract Climate change poses a significant threat to environmental sustainability and public health, leading to extreme weather events, rising sea levels, and biodiversity loss. Research on air pollution from African dust adversely associated with climate change highlights its significant role in trapping heat in the atmosphere and causing heat-related illnesses, cardiovascular disorders, and respiratory ailments. Smog, dust, acid rain, and ozone depletion also negatively impact ecosystems. The methods of the study also include the dynamics of climate change-induced air pollution. The implications for public health and environmental sustainability through GWR modeling and MODIS-NDVI analysis of controlling air pollution are crucial for reducing the climate crisis, safeguarding public health, and maintaining ecosystem sustainability. Results from particulate matter (PM 2.5-10), which consists of tiny particles with varying diameters, can enter the respiratory system through inhalation. This can lead to a diameter of less than 10 μm (PM 2.5-10). According to the relevant legislation, the limit value refers to the daily average value and must not exceed 50 μg/m3. While ozone in the stratosphere serves a protective function against ultraviolet radiation, excessive levels at ground level can be harmful and have been recorded in atmospheric samples ranging from 146.6 μg/m3 up to 702.3 μg/m3. impacting the respiratory and cardiovascular systems. Policy leaders, businesses, and individuals need to be proactive in reducing air pollution, adopting clean energy technology, and implementing stricter pollution rules. Stricter pollution rules, environmentally friendly transportation choices, and the adoption of clean energy technology. The sustainability of the ecosystem and public health are significantly impacted by climate change linked to air pollution. To solve these global problems and move toward a healthier, cleaner future for future generations, we must act now on climate justice. Key messages • Examine the impact of African dust air pollution on public health and its significant impacts from climate change, provide solutions to mitigate its effects on environmental sustainability in Europe. • Public health workers, Policymakers and stakeholders must prioritize reducing emissions and enforcing strict air quality laws to mitigate the negative impact of African dust on European populations.

Random Forest Spatial-Temporal and State Space Models to Assess the Impact of Bushfire-Induced Aerosol Events on Ozone Depletion in Australia

Serious concerns exist that the increasing frequency of fires may delay the recovery of ozone given increasing temperatures due to climate change. Australian bushfires from September 2019 to February 2020 were catastrophic. A random forest spatial-temporal (RF sp) analysis using satellite data to detect an association between Australian bushfires and stratosphere ozone on the local depletion of ozone in the vicinity of fires in three regions of Australia (Pacific Ocean, Victoria, NSW) has shown a significant reduction in ozone attributable to aerosols from fires. By intervention analysis, increases in aerosols in all three regions were shown to have a significant and ongoing impact 1–5 days later on reducing ozone (p < 0.0001). Intervention analysis also gave similar periods of aerosol exceedance to those found by Hidden Markov models (HMMs). HMMs established a significant and quantifiable decline in ozone due to bushfire-induced aerosols, with significant lags of 10–25 days between times of aerosol exceedance and subsequent ozone level decline in all three regions.

Temperature and Ozone Response to Different Forcing in the Lower Troposphere and Stratosphere

To evaluate the contributions of different forcings to the temperature and atmospheric composition changes between 1980 and 2020, we exploited the chemistry-climate model (CCM) SOCOLv3. The study examined ozone content and atmospheric temperature response to (1) ozone-depleting substances; (2) greenhouse gas concentrations, ocean surface temperature, and sea ice coverage; (3) solar irradiance; and (4) stratospheric aerosol loading and, separately, (5) greenhouse gas concentrations, (6) ocean surface temperature and sea ice coverage, and (7) NOx surface emissions. To evaluate the impacts of specific factors, we performed model runs driven by each factor (1–7) variability as well as a reference experiment that accounted for the influence of all factors simultaneously. We identified the relative contribution of different factors to the evolution of the temperature and ozone content of the lower troposphere and stratosphere from 1980 to 2020. The model results were in good agreement with the reanalyses (MERRA2 and ERA5). We showed that stratospheric ozone depletion before the Montreal Protocol introduction and partial recovery after that were chiefly driven by ODS. Stratospheric aerosol from major volcanic eruptions caused only short-term (up to 5 years) ozone decline. Increased greenhouse gas emissions dominate the ongoing long-term stratospheric cooling as well as tropospheric and surface warming. Solar irradiance contributed to short-term fluctuations but had a minimal long-term impact. Furthermore, our analysis of the solar signal in the tropical stratosphere underscores the complex interplay of solar radiation with volcanic, oceanic, and atmospheric factors, revealing significant altitudinal distributions of temperature and ozone responses to solar activity. Our findings advocate further innovative methodologies to take into account the nonlinearity of the atmospheric processes.

Comprehensive methodology for the integrating of the organic rankine Cycle-ORC with diesel generators in off-grid areas: Application to a Colombian case study

Efficient fuel management in diesel generator sets for power generation in non-grid areas is a persistent concern. In this context, the use of an Organic Rankine Cycle (ORC) to recover heat from exhaust gases from diesel generator sets represents a promising route for additional power generation. To undertake such projects, it is necessary to understand the critical parameters related to diesel engines, including the specific fuel consumption, mass flow, and exhaust gas temperature. These parameters are fundamental to the sizing process of the ORC heat recovery system. This study introduces an innovative methodology for evaluating the operation of diesel-ORC systems based on the load demand of off-grid communities. The proposed system is a viable solution for the generation of additional power with the objective of improving the overall efficiency and meeting higher energy demands in isolated areas. Four organic fluids were selected for the ORC: R245fa, benzene, cyclopentane, and toluene. This selection was made based on many criteria, including global warming potential (GWP), ozone depletion potential (ODP), and safety classification (ASHRAE 34). In addition, the exergy behaviors of these fluids were reviewed. A comparative analysis was subsequently conducted for a non-interconnected region of Colombia to evaluate the performance of a diesel generator operating independently and in conjunction with the diesel ORC system. The key indicators employed were fuel consumption savings (L/year), energy produced (MWh/year), levelized cost of energy (LCOE, USD/kWh), and payback period (years). The results demonstrated that, over the course of a 1-year simulation period, the benzene ORC system exhibited the highest overall energy efficiency, achieving a value of 41.38%. The exergy analysis indicated that toluene had lower irreversibilities, achieving an exergy efficiency of 44.78%, followed by benzene (43.5%. Furthermore, the diesel-ORC system using benzene demonstrated a notable decrease in the specific fuel consumption from 0.282 to 0.247 L/kWh, signifying a 10.52% reduction in the annual CO2eq emissions. The cost of electricity generation decreased by 4.3%, with investment payback periods not exceeding 14 years.

Recycling Fly Ash into Lightweight Aggregate: Life Cycle Assessment and Economic Evaluation of Waste Disposal

This study analyzed environmental impacts and economic feasibility to evaluate whether recycling fly ash, which has rarely been addressed in previous studies, as a raw material for lightweight aggregates can be a sustainable waste management alternative. This study presents a comparative analysis of three disposal scenarios: landfill disposal, recycling as cement raw material, and recycling as lightweight aggregate raw material. Nine environmental impacts were assessed through life cycle assessment (LCA): acidification, global warming, eutrophication, photochemical oxidation, stratospheric ozone depletion, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, and terrestrial ecotoxicity. The results showed that the landfill disposal scenario posed the greatest threat to global warming, eutrophication, and marine aquatic ecotoxicity, while the cement scenario had the greatest impact on stratospheric ozone depletion, human toxicity, and other ecotoxicity items while recycling as lightweight aggregate showed the lowest environmental impacts in most items except acidification and photochemical oxidation. Life cycle costing (LCC) analysis was also performed to compare the economic aspects of each scenario. The lightweight aggregate scenario is more energy-intensive and costly, but it has significant economic benefits due to the significant revenues from the products produced. Therefore, even though the cost is high, this scenario is considered economically advantageous. This study highlights that recycling fly ash into lightweight aggregate reduces environmental impacts, provides economic benefits, and is a better alternative to landfilling and recycling cement raw materials. It will also contribute to promoting sustainable practices of fly ash recycling.

Environmental sustainability, energy efficiency and uncertainty analysis of agricultural residue-based bioethanol production: A comprehensive life cycle assessment study

Bioethanol produced from agro-residue provides a sustainable alternative to fossil fuels, mitigating pollution, reducing waste, and promoting a circular economy. However, challenges arise in sustainable sourcing, resource conflicts, water quality concerns, and managing environmental footprints to maximize agro-residue-based bioethanol benefits. The environmental impacts, net energy ratio (NER), net energy value, water footprint, and uncertainties associated with bioethanol production from agro-residues are analyzed in this study. The analysis followed a cradle-to-gate approach using 1 L of bioethanol produced as a functional unit (FU), allowing for a direct comparison of the environmental performance of the different feedstocks. The result shows that rice straw-based bioethanol exhibited higher environmental impacts, particularly in terms of ecotoxicity, ionizing radiation, human toxicity, and ozone layer depletion, except for greenhouse gas emission, which is lowest for corn stover (0.37 kg CO2 eq. per FU) and highest for cassava straw (1.1 kg CO2 eq. per FU). Furthermore, the Cumulative Energy Demand analysis highlighted a significant reliance on fossil fuels from agricultural biomass throughout the bioethanol production process. The energy balance analysis shows that the agricultural residues are feasible for bioethanol production with NER of 1.20, 3.10, and 3.28 for rice straw, corn stover, and cassava straw, respectively. To enhance the accuracy and reliability of the LCA results, Monte Carlo simulation was employed to account for uncertainty and variability in the data. This methodology provides a better understanding of the impacts of bioethanol production, with a focus on sustainability and advancements in reducing our reliance on fossil fuels.