Generation Of Pollutants Research Articles

Greening up the fight against emerging contaminants: algae-based nanoparticles for water remediation

AbstractNanoparticles are commonly used for different purposes, including as photocatalysts, biosensors, antibacterial, antifungal, and anticancer agents. Recently, the synthesis of nanoparticles via biological techniques has become popular due to cost efficiency, sustainability, and the least secondary pollutants generation. Plants, algae, and microorganisms are primarily used to synthesize bio-nanoparticles. Algae-based nanoparticles have gained more attention due to their catalytic activity against emerging organic contaminants such as dyes, phenols, and organosulfur compounds. Nevertheless, a systemic evaluation of the potential of algae-based nanoparticles in environmental remediation is yet to be conducted. This paper reviews recent progress in the biosynthesis of algae-based nanoparticles and the potential use of algae-based nanoparticles in environmental remediation. Furthermore, the review examines the factors that affect the properties and behaviors of algae-based nanoparticles. Additionally, the review briefly discusses other medical and industrial applications as well as advantages over physically and chemically synthesized nanoparticles. Challenges associated with the production process and usage of algae-based nanoparticles are also discussed, including the difficulty of predicting the properties of nanoparticles and adapting to large-scale processes. Overall, algae-based nanoparticles have several advantages, including their high stability and surface activity due to the presence of surface functional groups from algae species used for the synthesis of algae-based nanoparticles. However, further research is required to address the knowledge gaps and potential key research areas. Graphical Abstract

Water-energy-food(WEF) nexus efficiency of dynamic slack-based measure in 31 provinces and regions in China

In recent years, China's rapid economic growth has positioned it as the world's second-largest economy by 2011. Despite emphasizing energy efficiency and environmental protection since the 1990s, China still grapples with resource wastage and environmental pollution in its development. Consequently, controlling negative environmental impacts is an important issue in achieving balanced development in China, as well as in other economies around the world. This study collected crucial Water-Energy-Food Nexus (WEF Nexus) variables from 31 Chinese provinces and regions between 2016 and 2020. It utilized the Dynamic Slack-Based Measure (DSBM) model to assess the overall WEF Nexus efficiency across these provinces and regions. Empirical results show: a) After incorporating pollutant emissions, the WEF Nexus total efficiency declined from 0.5703 to 0.5124, indicating the impact of pollutant emissions on overall efficiency. This suggests a potential need for enhanced efforts across Chinese provinces to reduce emissions. b) Among the studied provinces and regions, ten, including Beijing, Guangdong, Hainan, and Jiangsu, exhibited a WEF Nexus total efficiency value of 1, while Hebei, Guangxi Zhuang, and Xinjiang Uygur Autonomous Regions showcased the poorest overall efficiency. c) China's population growth has created pressure on WEF Nexus resource and environmental configurations, leading to substantial pollutant generation alongside the pursuit of rapid GDP growth, affecting living environments. This study emphasizes crucial variables related to WEF Nexus and environmental pollution in urban development. It not only aids decision-makers in effectively allocating input and output resources for sustainable resilient urban planning but also highlights the impact of environmental pollution on the overall efficiency of WEF Nexus.

Effect of O2/n-C5H12 Ratio on Oxygenates Production from Plasma N-pentane Partial Oxidation

Objective: Non-thermal plasma is a promising method for producing clean fuels. This work provides a deeper understanding of the impact of O2/n-C5H12 ratio on the partial oxidation of n-pentane from both physical and chemical perspectives. Moreover, this work offers insight into improving fuel combustion efficiency and technical support for the preparation of clean fuels. Methods: An experimental system based on dielectric barrier discharge plasma was established. The discharge characteristics and product generation status of n-pentane partial oxidation were measured by changing the concentration of oxygen and n-pentane to evaluate different O2/n-C5H12 ratios. Results: Research on discharge characteristics showed that the O2/n-C5H12 ratio did not affect the discharge mode, and typical Lissajous shapes were present at different ratios. Changing the O2/n-C5H12 ratio affected the oxygen concentration, average electron energy or electron density, and background temperature. As the O2/n-C5H12 ratio increased, the conversion of the n-pentane partial oxidation reaction increased. However, changing the O2/n-C5H12 ratio did not affect the type of generated products. The oxygenates exhibited a volcano curve, and an O2/n-C5H12 ratio of 1.00 achieved the highest selectivity of 35.1%. As the O2/n-C5H12 ratio continued to increase, the selectivity of oxygenates decreased and the selectivity of CO2 increased. This was potentially due to a shift from partial oxidation toward complete oxidation, which led to the generation of secondary pollutants. Thus, higher O2/n-C5H12 ratios were not conducive to clean fuel production and environmental friendliness. Conclusion: In the partial oxidation of n-pentane, the highest clean fuel production rate was achieved when the O2/n-C5H12 ratio was 1.00. When this ratio exceeded 1.00, the reaction shifted toward complete oxidation, producing secondary pollutants. This study provides ideas for improving fuel combustion efficiency and technical support for the preparation of clean fuels.

Simulating the land use change effects on non-point source pollution in the Duliujian River Basin.

The uncertainty in the generation and formation of non-point source pollution makes it challenging to monitor and control this type of pollution. The SWAT model is frequently used to simulate non-point source pollution in watersheds and is mainly applied to natural watersheds that are less affected by human activities. This study focuses on the Duliujian River Basin (Xiqing section), which is characterized by a dense population and rapid urbanization. Based on the calibrated SWAT model, this study analyzed the effects of land use change on non-point source pollution both temporally and spatially. It was found that nitrogen and phosphorus non-point source pollution load losses were closely related to land use type, with agricultural land and high-density urban land (including rural settlements) being the main contributors to riverine nitrogen and phosphorus pollution. This indicates the necessity of analyzing the impact of land use changes on non-point source pollution loads by identifying critical source areas and altering the land use types that contribute heavily to pollution in these areas. The simulation results of land use type changes in these critical source areas showed that the reduction effect on non-point source pollution load is in the order of forest land > grassland > low-density residential area. To effectively curb surface source pollution in the study area, strategies such as modifying urban land use types, increasing vegetation cover and ground infiltration rate, and strictly controlling the discharge of domestic waste and sewage from urban areas can be implemented.

Green disposal of waste smartphone protective film: Efficiency, mechanism, bench-scale test and secondary waste reutilization

The manufacture and obsolescence of smartphones produce numerous waste plastic accessories (e.g., waste smartphone protective film (WSPF)), possessing immense potential for recycling. However, available recycling technologies have limitations such as substrate damage and secondary pollutant generation. The present study aimed to develop a green disposal method that not only recycled polyethylene terephthalate (PET) from WSPF, but also reused the stripped polyacrylate (PAA) adhesive as an adsorbent to reduce solid waste generation. When the WSPF was treated in 1 mol/L NaOH solution at 90 °C, the PAA hydrolyzed to two main by-products of 1-butanol and 2-ethylhexanol, weakening the binding strength between PAA and PET and then efficient separation of them. Further bench-scale test revealed that over 97.2% of detachment efficiency toward PAA was achieved during continuous treatment of 17 batches of WSPF (200 g for each) without supplement of NaOH and generation of wastewater. Meanwhile, the economic evaluation indicated that the recycling method would generate a net profit margin of 647% for the second year without considering the incurrence of new cost and input. Additionally, the pyrolysis of waste PAA enabled its conversion into potential adsorbent, which showed 2 to 4 times enhanced adsorption capacity toward styrene and ethyl acetate after modification with NaOH solution. This study provides a green method for recycling waste plastics and inspires a referable solution for solid waste treatment in the smartphone industry.

Comparative Life Cycle Assessment of a centrifugal compressor impeller: Hybrid technology production versus welding production

Sustainable development is one of the main objectives in the turbomachinery sector to achieve the climate neutrality targets set by 2050 protocols. The manufacturing industry consumes an average of 23% of global energy, significantly contributing to the generation of greenhouse gases and other pollutants. Therefore, it is crucial to research technological solutions aimed at reducing consumption for the benefit of the environmental sustainability of the products manufactured. This study presents a comparative environmental impact assessment using the Life Cycle Assessment (LCA) methodology to evaluate the sustainability of two technological alternatives used to produce centrifugal impellers in the industrial sector. The first process analyzed deals with making an impeller by welding the shroud to the impeller body. The second process involves producing the component from a semi-finished product, machined through milling and Electrical Discharge Machining (hybrid solution). The study has been conducted at Nuovo Pignone company. It is based on primary inventory data collected through specific measurement campaigns and modeled using the environmental database Ecoinvent v3.9. The results were produced using the ILCD Midpoint method, and four different impact categories were investigated: Climate Change, Human Toxicity, Cancer Effects, and Freshwater Ecotoxicity. The results demonstrate that the solution produced through hybrid manufacturing is generally less impactful compared to the welded one. The insight implemented in the work is functional in drafting suggestions for manufacturers and customers to reduce the environmental burdens of the examined product.

Expansion-flow-modulated 3D printing of vertically aligned graphene photofuel cell

Channel-aligned regulation of photoelectrode within the bulk structure to generate eminent light absorbance and high-level pollutant adsorption is pivotal but challenging for realizing high-performance photofuel cell (PFC) system. Herein, we demonstrated an effective and scalable expansion-flow-modulated direct ink writing (DIW) 3D printing strategy for controllably constructing microlattice photoelectrode, with multiscale well-interconnected oriented channels built by layer-by-layer highly-regular assembly of filaments and vertical alignment of graphene nanosheets within filaments as well as uniform coupling of abundant photoactive nanoparticles to highly ordered channel walls. The unique architectural features enabled high-speed and effective diffusion/trapping of wastewater pollutants throughout the entire photoelectrode, and meanwhile facilitated ready spreading of incident light into the photoelectrode interior to yield high light absorption. As a result, an integrated 3D-printed vertically-aligned PFC (3DP VAPFC) assembled with as-fabricated photoelectrode exhibited its powerful capability for efficiently converting wastewater pollutants into electric energy under sunlight, with remarkable cycling stability and maximum power density of 0.11 mW cm−2. This work opens a promising route for architecting advanced photoelectrode toward PFC devices with highly efficient degradation and electricity generation of pollutants.

Spatial scale effects of landscape patterns on non-point source pollution: A case study of Taizi River Basin in Northeast China

River water quality is influenced by natural processes and human activities. Multi-scale landscape patterns can affect river water quality by altering the generation and transport processes of pollutants at different spatial scales. Taking Taizi River Basin in Northeast China as an example, we analyzed the relationship between landscape patterns and non-point source pollution in rivers based on water quality monitoring data and land use data by using correlation analysis and redundancy analysis methods. We aimed to determine the key spatial scales for the responses of landscape patterns to non-point source pollution and identify the key landscape indices influencing river non-point source pollution. The results showed that water quality of Taizi River Basin had seasonal differences, with better water quality during the flood season than non-flood season. Spatially, total nitrogen (TN) and total phosphorus (TP) were higher at the confluence points of tributaries and downstream areas. The impact of landscape patterns on non-point source pollution was stronger during the non-flood season than the flood season, while the influence on TN was stronger than on TP. At the spatial scale of within 500 m buffer zone during the flood season and at the sub-watershed scale during the non-flood season, landscape patterns showed the highest explanatory power for the variations of TN and TP. At the type level, built-up land, cropland, and bare land were positively correlated with TN and TP, while forest was negatively correlated with TN and TP, which were the key types influencing non-point source pollution. At the landscape level, patch density, percentage of like adjacencies, and contagion index were key indicators affecting watershed water quality. Lower patch density was associated with better connectivity and aggregation of "sink" landscapes, leading to better purification effects on TN, but more pronounced retention effects on TP. Conversely, higher landscape diversity and denser pattern of multiple types would cause the deterioration of water quality. Our results suggested that rational allocation of landscape types within the watershed and riparian buffer zones, appropriately enriching landscape diversity, and optimizing landscape aggregation and connectivity would be effective measures for improving water quality and achieving sustainable ecological management.

Exploring the Influence of Dynamic Indicators in Urban Spaces on Residents’ Environmental Behavior: A Case Study in Shanghai Utilizing Mixed-Methods Approach and Artificial Neural Network (ANN) Modeling

The main aim of this article is to evaluate the impact of dynamic indicators associated with urban spaces on the environmental behavior of residents in Shanghai, China. With the city experiencing rapid urbanization and increasing environmental concerns, it is crucial to understand how the design and management of urban spaces can encourage pro-environmental attitudes and actions among the population. The study specifically focuses on dynamic indicators, namely vitality, accessibility, quality, and walkability, to develop a comprehensive understanding of the utilization and experience of urban spaces. The research outcomes will make valuable contributions towards Shanghai’s objectives of achieving environmental sustainability, while also providing insights that have broader relevance to sustainable urban development globally. As the built environment significantly influences energy consumption, resource utilization, pollution generation, and overall human wellbeing, attaining urban sustainability is of paramount importance. The findings of this study will aid in informing strategies and policies that promote sustainable practices, not only benefiting Shanghai but also serving as a valuable resource for urban development initiatives worldwide. Sustainable urban design principles, including compactness, density, mixed land use, greening, and walkability, have been associated with pro-environmental behaviors, including reduced reliance on automobiles, increased walking and cycling, and heightened environmental consciousness. Nevertheless, the relationship between the built environment and sustainability behaviors is intricate and is influenced by multiple factors. Consequently, further research is necessary to comprehend how specific spatial and temporal dynamics impact environmental behaviors within urban settings. In this study, an artificial neural network (ANN) was developed to estimate the quality and walkability of an area and environmental behaviors by considering the augmented vitality and accessibility factors. The ANN’s predictions demonstrate that higher levels of vitality and accessibility positively contribute to improved walkability and environmental behaviors. The accuracy of the ANN’s predictions was assessed using linear regression, which yielded acceptable error rates when compared with experimental results.

Environmental-Specific Servant Leadership and Organizational Environmental Citizenship Behavior: The Mediating Role of Harmonious Environmental Passion

Activities within the tourism industry contribute to environmental issues, including climate change, resource depletion, emission of pollutants impacting air and water quality, and generation of sound and light pollution. Furthermore, these actions can lead to species extinction. Leadership has been identified as a key factor in enhancing green performance both at the individual and organizational levels. Our objective is to elucidate the mechanisms and contextual limitations influencing the correlation between environmental-specific servant leadership and organizational environmental citizenship behavior, utilizing insights from the conservation of resource theory. The suggested connections were explored through the acquisition of data via a survey conducted among 300 employees and their supervisors employed across diverse organizations within the hospitality and tourism sectors. The data underwent analysis using PLS-SEM, and the empirical findings substantiated that the relationship between environmental-specific servant leadership and organizational environmental citizenship behavior is mediated by harmonious environmental passion. These findings contribute to the conservation of resource theory.

Sustainable approach for the treatment of dye-containing wastewater – a critical review

Abstract In the world’s rapidly expanding economy, textile industries are recognized as a substantial contributor to economic growth, but they are one of the most significant polluting industrial sectors. Dye-contaminated water sources can pose serious public health concerns, including toxicity, mutagenicity, and carcinogenicity among other adverse health effects. Despite a limited understanding of efficacious decolorization methodologies, the pursuit of a sustainable strategy for the treatment of a wide spectrum of dyes remains a formidable challenge. This article conducted an exhaustive review of extant literature pertaining to diverse physical, chemical, biological, and hybrid processes with the aim of ascertaining their efficacy. It also elucidates the advantages and disadvantages, cost considerations, as well as scalability impediments of the treatment methodologies, thereby facilitating the identification of optimal strategies for establishing techno-economically efficient processes in the sustainable handling of these effluents. The hybrid configuration exhibited superior efficiency and was documented to surmount the limitations and constraints inherent to individual techniques. The study also revealed that most of the proven and established dye removal techniques share a common limitation viz., the generation of secondary pollution (i.e., sludge generation, toxic intermediates, etc.) to the ecosystem.

Numerical Simulation Study on Combustion of Low Calorific Value Waste Blended with Biomass.

Numerical simulations of a 600 t/day waste incinerator was carried out using the fluid dynamic incinerator code and Fluent to evaluate the effect of biomass blending on furnace temperature, pollutant generation, and selective noncatalytic-reduction (SNCR) denitrification when treating low calorific-value waste. The results show that as the biomass blending ratio increases, the water content gradually decreases, the calorific value increases, and the maximum temperature of the incinerator gradually increases from 1227 to 1408 K, while the content of exported NOx increases from 579 to 793 mg/Nm3; during the combustion of low-quality waste, the residence time of the flue gas in the high-temperature region (above 1123 K) is 1.62 s. When the biomass blending ratio exceeds 20%, the residence time of the flue gas in the high-temperature region is more than 2 s, which can effectively curb the generation of dioxin. When the biomass blending ratio is 20%, and the normalized stoichiometric ratio (2nurea/nNO) of urea injected into the SNCR is 1.1, the NOx concentration at the outlet is 230.08 mg/Nm3, which satisfies the NOx emission standard of less than 250 mg/Nm3.

Effect of liquid ammonia HPDI strategies on combustion characteristics and emission formation of ammonia-diesel dual-fuel heavy-duty engines

Reducing carbon emissions from internal combustion engines has become a crucial topic due to the pressure brought about by global warming. Ammonia, a carbon-free fuel, has significant potential for heavy-duty diesel engine applications. However, the laminar flame speed of ammonia fuel is relatively slow, resulting in suboptimal combustion performance. Therefore, the present study focuses on ammonia-diesel dual-fuel heavy-duty engines. A novel liquid ammonia high-pressure direct injection (HPDI) strategy has been developed to address the challenges associated with poor combustion performance and increased unburned ammonia emissions in ammonia-diesel dual-fuel internal combustion engines. Firstly, a three-dimensional numerical simulation method was utilized to establish and verify a model of a heavy-duty internal combustion engine that incorporates HPDI of liquid ammonia. Afterward, numerical studies comparing the engine's combustion and emission characteristics are conducted with varied ammonia energy fractions, liquid ammonia injection timings, and liquid ammonia injection directions. The results indicate that, compared to the pure diesel mode, the novel liquid ammonia HPDI strategy can alter the combustion mode, significantly improving fuel–air mixture efficiency. This leads to more thorough combustion. After replacing 80% of the fuel energy input with ammonia, there is still an increase of 8.9% in indicated mean effective pressure and a 10.6% improvement in indicated thermal efficiency. Moreover, modifying the HPDI strategy reduces greenhouse gas emissions effectively, and due to the thermal de-NOx reaction, there is a notable decrease in NOx emissions. Furthermore, by altering the liquid ammonia injection timing and direction, finer control of fuel combustion and pollutant generation can be achieved, thereby reducing unburned ammonia emissions in conditions of high ammonia energy fractions.

Spectral effects of radiating gases and soot on an experimental aero-engine combustion chamber using full-spectrum k-distribution method

Radiative heat transfer is the main mode of heat transfer and has been proven to be important in the aero-engine combustion. Those radiating gases and soot resulted from combustion may display very strong spectral, or “nongray” behavior, which is difficult to both characterize and evaluate. In this work, the full-spectrum k-distribution (FSK) method is employed to resolve the spectral behavior of both radiating gases and soot during combustion in an experimental aero-engine. Different FSK-based spectral treatments are combined to illustrate how the spectral behavior affects the aero-engine combustion. Those weighted-sum-of-gray-gases (WSGG) results previously done by the authors (Wang, et al. 2024) are also partially compared to the FSK results in this work. Results show that different FSK-based spectral treatments result in small differences for temperature distribution of the flow field. However, since different spectral models are found to impose a considerable effect on radiative heat transfer rate, it is inferred that spectral behavior may be deeply coupled with the generation of pollutants. Results also show that the wall temperature of the combustor liner is highly affected by the spectral model: ignoration of soot radiation underestimates the wall temperature while assuming soot to be gray overestimates the wall temperature. Therefore, high-fidelity spectral models are recommended during the modelling of aero-engine combustion.

Assessment of Microplastic Pollution and Estimation of Annual Emission Volume in the Dongshan Canal of Yichang City

Microplastics, as an emerging pollutant, have garnered global attention. Urban areas are key hotspots for the generation of microplastic pollution, whereas urban water bodies act as vital conduits for the dissemination of microplastics to other freshwater environments. In this study, the Dongshan Canal in the urban area of Yichang City was selected as the research subject. Through field sampling, microscopic observation, and Fourier infrared spectroscopy analysis conducted in July and October 2022, the occurrence characteristics and potential pollution sources of microplastics in the water body of the Dongshan Canal were identified and analyzed. The ecological risk and annual emission volume of microplastics in the water body were quantitatively assessed using the risk index (H), pollution load index (PLI) model, and proportional flow method. The results indicated that the average abundances of microplastics in the surface water of the Dongshan Canal were (7 295±1 051) n·m-3 (July) and (5 145±762.6) n·m-3 (October). Fibrous microplastics (27.63%-63.23%), microplastics with a size of <0.5 mm (75.68%-96.2%), and colored microplastics (22.73%-61.83%) dominated the samples, with PE (30.1%) and PET (26.33%) being the predominant materials. The assessment results from the two models classified the ecological risk index of the Dongshan Canal as class Ⅲ, whereas the overall pollution load fell into class I, with certain sampling points reaching class Ⅱ. Estimates revealed that the Dongshan Canal transports approximately 3.37 t of microplastics to the Yangtze River annually. Overall, the microplastic pollution level in the Dongshan Canal of Yichang City could be considered moderate, with potential sources of pollution including laundry wastewater, personal care products, and plastic waste.

Effect of NaClO disinfectant treatment on the yields, components and combustion characteristics of typical medical waste pyrolysis products

Medical waste with pathogenic bacteria is infectious and toxic, which could cause significant harm to the environment and human health without being adequately disposed of. Pyrolysis-incineration coupled technology can realize the rapid and efficient treatment of medical waste while reducing the generation of pollutants. Whereas, the NaClO disinfection treatment, which is a necessary process prior to transfer and disposal of medical waste, has not been sufficiently described in terms of its effect on the pyrolysis yield and components characteristics of medical waste. This study clarified the influence mechanism of NaClO disinfection treatment on the yields, components, and combustion characteristics of pyrolysis products derived from typical medical waste (cotton swab sticks, masks, and latex gloves). The results showed that NaClO disinfection treatment induced depolymerization of the internal structure of the polymer and increased pyrolysis tar and syngas at 400 °C. In addition, NaClO disinfection treatment reduced syngas quality, which was attributed to generating more CO2 and inhibiting alkynes gas production under medium-low pyrolysis temperatures. Furthermore, the condensation or cyclization of light components into heavy components in the tar increased the average double-bond equivalents and oxygen content, which was detrimental to tar ignition and combustion. Moreover, the combustion performance of char was improved because there was a tendency for the conversion of graphitic carbon to fatty carbon in the char. These findings elucidate the feasibility of pyrolysis-incineration coupled technology for the fast and effective treatment of medical waste.

Review of the Design and Operation Criteria of a DC Submerged Arc Discharge Carbon Nanostructure Synthesis Installation

The submerged arc discharge (SAD) allows the production of high-quality carbon nanostructures. The SAD method uses simple and inexpensive equipment. However, the carbon nanostructures obtained contain contaminants that are difficult to remove. The study of the published articles shows that reporting similar operating parameters informs quite different results. Reducing the generation of pollutants requires optimization of the design and the operation of installations. Nevertheless, the study of the state-of-the-art indicates that this aspect has been underestimated, which is manifested in the absence of publications on this subject. On the other hand, the increase in the production scale causes new problems that are not manifested in small-volume productions that are carried out in a research laboratory. The present work aims to analyze the SAD installation design and operation criteria to reduce the presence of contaminants. This study indicated that the key elements of the design and the operation are the electrodes alignment, feeding and attachment mechanisms, the electrode micropositioning system, the synthesis reactor design, the sensitive parameters control, the data acquisition system, and the selection of the liquid medium. Herein, these elements are analyzed and the best strategies for their design and operation are exposed. Those aspects relevant to scaling up of production are emphasized.

Profiling wastewater characteristics in intra-urban catchments using online monitoring stations.

This study aims to investigate the differences in intra-urban catchments with different characteristics through real-time wastewater monitoring. Monitoring stations were installed in three neighbourhoods of Barcelona to measure flow, total chemical oxygen demand (COD), pH, conductivity, temperature, and bisulfide (HS-) for 1 year. Typical wastewater profiles were obtained for weekdays, weekends, and holidays in the summer and winter seasons. The results reveal differences in waking up times and evening routines, commuting behaviour during weekends and holidays, and water consumption. The pollutant profiles contribute to a better understanding of pollution generation in households and catchment activities. Flows and COD correlate well at all stations, but there are differences in conductivity and HS- at the station level. The article concludes by discussing the operational experience of the monitoring stations.

Computational exploration of oxide-based double perovskites Sr2MgWO6 and Ba2BiVO6 for photocatalysts for sustainable degradation processes

First-principles calculations have been utilized to investigate the photocatalytic degradation, structural properties, electronic properties, population inversion, effective mass, redox potential, and optical properties of oxide-based double perovskites Sr2MgWO6 and Ba2BiVO6. The calculated value of τG is 0.83 for Sr2MgWO6 and 0.97 for Ba2BiVO6. The electronic properties indicate the semiconducting behavior of studied materials, which enable the efficient formation of electron-hole pairs upon photon absorption. The photocatalytic efficiency of perovskite materials was determined by studying the effective mass ratio. The optical parameters exhibit a strong correlation with the underlying electronic band structure. The electronegativity values were computed to be 5.292 eV and 5.206 eV for Sr2MgWO6 and Ba2BiVO6, respectively. The conduction band edges value are found to be −0.523 eV for Sr2MgWO6 and 0.146 eV for Ba2BiVO6. Based on their redox potentials, the Sr2MgWO6 and Ba2BiVO6 oxide perovskites have a high potential for use in photocatalytic applications, specifically in the generation and degradation of organic pollutants. These perovskites degrade organic pollutants with high efficiency and can effectively contribute to environmental treatment. Their strong capacity for reduction and oxidation reactions gives them an advantageous capability to degrade organic pollutants.

Indoor Air Sources of Outdoor Air Pollution: Health Consequences, Policy, and Recommendations: An Official American Thoracic Society Workshop Report.

Indoor sources of air pollution worsen indoor and outdoor air quality. Thus, identifying and reducing indoor pollutant sources would decrease both indoor and outdoor air pollution, benefit public health, and help address the climate crisis. As outdoor sources come under regulatory control, unregulated indoor sources become a rising percentage of the problem. This American Thoracic Society workshop was convened in 2022 to evaluate this increasing proportion of indoor contributions to outdoor air quality. The workshop was conducted by physicians and scientists, including atmospheric and aerosol scientists, environmental engineers, toxicologists, epidemiologists, regulatory policy experts, and pediatric and adult pulmonologists. Presentations and discussion sessions were centered on 1) the generation and migration of pollutants from indoors to outdoors, 2) the sources and circumstances representing the greatest threat, and 3) effective remedies to reduce the health burden of indoor sources of air pollution. The scope of the workshop was residential and commercial sources of indoor air pollution in the United States. Topics included wood burning, natural gas, cooking, evaporative volatile organic compounds, source apportionment, and regulatory policy. The workshop concluded that indoor sources of air pollution are significant contributors to outdoor air quality and that source control and filtration are the most effective measures to reduce indoor contributions to outdoor air. Interventions should prioritize environmental justice: Households of lower socioeconomic status have higher concentrations of indoor air pollutants from both indoor and outdoor sources. We identify research priorities, potential health benefits, and mitigation actions to consider (e.g., switching from natural gas to electric stoves and transitioning to scent-free consumer products). The workshop committee emphasizes the benefits of combustion-free homes and businesses and recommends economic, legislative, and education strategies aimed at achieving this goal.