Smog Formation Research Articles

Pollution investigation of wintertime VOCs in the coastal atmosphere of the Yellow Sea: Insights from on-line photoionization-induced CI-TOFMS.

Volatile Organic Compounds (VOCs) are pivotal in tropospheric atmospheric chemistry, significantly impacting the formation of photochemical smog, fine particle pollution, and the atmospheric oxidizing potential, all of which affect air quality. Chemical ionization time-of-flight mass spectrometry, renowned for its exceptional sensitivity, precision, and swift response time, has proven to be exceptionally effective for real-time VOCs monitoring. In this study, a custom-built photoionization-induced CI-TOFMS was deployed to individually detect 116 VOCs standard gases specified by the United States Environmental Protection Agency, quantifying their responses and establishing a distinctive mass spectrogram database. A 12-day comparative analysis with online gas chromatography coupled with a flame ionization detector and mass spectrometer demonstrated the high reliability of the PICI-TOFMS, confirming its effectiveness for field VOCs monitoring. During two months of stationary monitoring, the PICI-TOFMS could further refine the timing of pollution events with high temporal resolution and identified four distinct air pollution episodes, including local emissions, coal burning, sand and dust transport and festival-related pollution. Employing a Hysplit model, the Concentration Weighted Trajectory model, and a source apportionment method based on tracer gases, the air trajectories were calculated and contributions from different potential source areas were quantified. Our findings reveal that transport was the main contributor to pollution in December 2022, while burning was the primary source in January 2023. This study refines our understanding of the dynamics of air pollution, providing valuable insights into the temporal and spatial distribution of VOCs and their sources.

Achieving universal energy access in remote locations using HOMER energy model: a techno-economic and environmental analysis of hybrid microgrid systems for rural electrification in northeast Nigeria

The developing world continues to face substantial obstacles to achieving affordable and dependable electricity access. This issue is especially pertinent for Nigeria, where diesel generators are widely relied upon in urban and rural regions because of an underdeveloped and unreliable national grid. The lack of grid reliability is worsened in Northeastern Nigeria, an area plagued by conflict, extreme poverty, and grid infrastructure deterioration. This study investigates the feasibility of implementing community-scale microgrids in rural areas without grid connection access. It focuses on assessing the technical, economic, and environmental aspects of utilizing these microgrids to deliver inexpensive and dependable electricity to underserved populations to increase energy access. A case study was conducted in Kabuiri, a village with an estimated population of 2,300 residents and an estimated load demand of 610 kWh per day. A hybrid microgrid system was designed and optimized to meet the community’s load demand using HOMER software, sized to produce 610 kWh/day of electricity with a renewable penetration of 99%. The optimal solar PV/battery/generator system had a levelized cost of electricity (LCOE) of $ 0.093 per kWh, a net present cost (NPC) of $266,709, and an annual operating cost of $9,110. The system contributed 1,624 kg CO2 eq/year of global warming potential and 56.81 kg O3 eq/year of smog formation during operation. Sensitivity analysis showed that the system could effectively react to or adapt to substantial increases in diesel prices, requiring only marginal increases in photovoltaic capacity and reduced generator usage to maintain the most cost-efficient operation. Additionally, the system model can be adapted based on the population of the remote community without substantially impacting the LCOE, however, the NPC increases with increase in population size. This research will aid in increasing energy access in remote locations by providing insights to stakeholders and energy access project developers.

Synergistic removal of nitrogen oxides and toluene and their interaction mechanism on Cu-MnO2 catalyst

Volatile organic compounds (VOCs) and nitrogen oxides (NOx) contribute significantly to the formation of haze and photochemical smog, posing substantial threats to both the environment and human health. Toluene, a typical VOCs, often coexists with NOx in various mobile or stationary flue gases. However, the current understanding of the mutual influence of their synergistic removal remains limited. In this work, the Cu-MnO2 catalyst was prepared using the precipitation method, which demonstrated synergistic removal activity for both NOx and toluene, as well as selectivity towards N2 and CO2. The interaction mechanism was investigated, particularly focusing on the effect of NOx on the adsorption and oxidation performance of toluene. The degree to which NOx inhibits toluene increases with NOx concentration. Furthermore, multiple inhibition ways of NOx on toluene oxidation were discovered, including competitive adsorption of NOx and toluene on the catalyst surface, as evidenced by the breakthrough experiments. TPD and XPS characterization indicated that the addition of NOx reduces oxygen vacancies, thereby weakening toluene oxidation performance. In addition, in-situ DRIFT characterization was conducted, and it was found that the addition of NOx affected the oxidation process of toluene. Apart from benzyl alcohol, benzaldehyde, and benzoic acid, intermediate nitrite species also appeared, and their deposition was also the reason for the decrease in toluene oxidation ability. This work provides new insights into the interaction mechanisms between various components in the collaborative removal of NOx and VOCs.

Construction of highly efficient In2O3/SnO2 sensor for real-time NO2 monitoring at near room temperature

NO2 is a dangerous gaseous pollutant, which is also a precursor to the formation of photochemical smog and ozone. It has negative impacts on the environment and human beings at local, regional and even the whole global scale. In this context, it is imperative to develop the efficient sensing materials for detecting NO2 gas. In this study, a near room temperature NO2 sensing material (In2O3/SnO2 heterostructure) with “4S” index (selectivity, sensitivity, speed, stability) was constructed, it overcomes the drawbacks of traditional detection techniques and solves the unavoidable problems of metal oxide semiconductors in the sensing process (high temperature, cross response, weak response at low concentration, etc.). Meanwhile, the synergy between the surface structure and heterostructure interface of In2O3/SnO2 has been thoroughly analyzed. More importantly, this study also sampled and monitored ambient air samples from different geographical locations and different time points in cities, which provides strong support for promoting the application of MOS sensors in real environment.

Comparative Life Cycle Assessment of Bacterial and Thermochemical Retting of Hemp.

The processes of hemp bast fiber retting, forming, and drying offer the opportunity for value-added products such as natural fiber-reinforced composites. A new process for the retting of raw bast fibers through enzyme-triggered self-cultured bacterial retting was developed in the lab-scale setup. This study focused on comparing the energy consumption and environmental impacts of this bacterial retting process with the thermochemical retting process currently widely used to obtain lignocellulosic fibers for composites. The gate-to-gate life cycle assessment (LCA) models of the two retting processes were constructed to run a comparison analysis using the TRACI (the tool for the reduction and assessment of chemical and other environmental impacts) method for environmental impacts and the cumulative energy demand (CED) method for energy consumptions. This work has demonstrated the advantages of the bacterial retting method from an environmental standpoint. The result of our research shows about a 24% gate-to-gate reduction in CED for bacterial retting and 20-25% lower environmental impacts relating to global warming, smog formation, acidification, carcinogenics, non-carcinogenics, respiratory effects, ecotoxicity, and fossil fuel depletion when compared to that of thermochemical retting.

Quantification of the environmental impact of radiotherapy and associated secondary human health effects: a multi-institutional retrospective analysis and simulation

The health-care industry is a substantial contributor to global greenhouse gas emissions, yet the specific environmental impact of radiotherapy, a cornerstone of cancer treatment, remains under-explored. We aimed to quantify the emissions associated with the delivery of radiotherapy in the USA and propose a framework for reducing the environmental impact of oncology care. In this multi-institutional retrospective analysis and simulation study, we conducted a lifecycle assessment of external beam radiotherapy (EBRT) for ten anatomical disease sites, adhering to the International Organization for Standardization's standards ISO 14040 and ISO 14044. We analysed retrospective data from Jan 1, 2017, to Oct 1, 2023, encompassing patient and staff travel, medical supplies, and equipment and building energy use associated with the use of EBRT at four academic institutions in the USA. The primary objective was to measure the environmental impacts across ten categories: greenhouse gases (expressed as kg of carbon dioxide equivalents [CO2e]), ozone depletion, smog formation, acidification, eutrophication, carcinogenic and non-carcinogenic potential, respiratory effects, fossil fuel depletion, and ecotoxicity. Human health effects secondary to these environmental impacts were also estimated as disability-adjusted life years. We also assessed the potential benefits of hypofractionated regimens for breast and genitourinary (ie, prostate and bladder) cancers on US greenhouse gas emissions using an analytic model based on the 2014 US National Cancer Database for fractionation patterns and patient commute distances. We estimated that the mean greenhouse gas emissions associated with a standard 25-fraction EBRT course were 4310 kg CO2e (SD 2910), which corresponded to 0·0035 disability-adjusted life years per treatment course. Transit and building energy usage accounted for 25·73% (1110 kg CO2e) and 73·95% of (3190 kg CO2e) of total greenhouse gas emissions, respectively, whereas supplies contributed only 0·32% (14 kg CO2e). Across the other environmental impact categories, most of the environmental impact also stemmed from patient transit and energy use within facilities, with little environmental impact contributed by supplies used. Hypofractionated treatment simulations suggested a substantial reduction in greenhouse gas emissions-by up to 42% for breast and 77% for genitourinary cancer-and environmental impacts more broadly. This comprehensive lifecycle assessment of EBRT delineates the environmental and secondary health impacts of radiotherapy, and underscores the urgent need for sustainable practices in oncology. The findings serve as a reference for future decarbonisation efforts in cancer care and show the potential environmental benefits of modifying treatment protocols (when clinical equipoise exists). They also highlight strategic opportunities to mitigate the ecological footprint in an era of escalating climate change and increasing cancer prevalence. Mount Zion Health Fund.

TiO<sub>2</sub>-ZnO Catalyst: A New Composite For Selective Catalytic Reduction of NO<sub>x</sub> with NH<sub>3</sub>

Investigations have underscored the pivotal role of NOx gases in the formation of smog and acid rain, posing threats to human health and ecosystems. Selective Catalytic Reduction (SCR) has emerged as a promising strategy for curtailing NOx emissions. SCR involves the catalytic conversion of nitrogen oxides into benign nitrogen and water vapour, thereby offering a viable approach. In this study, a new composite of low-temperature selective catalytic reduction (LT-SCR) catalyst is synthesized by impregnating ZnO onto TiO2 ceramic substrate. The introduction of ZnO not only provides a high surface area but also results in the formation of a catalyst. This research presents the outcomes of an investigation involving a range of catalysts employed in SCR, including a composite catalyst composed of titanium dioxide and zinc oxide. The objective is to evaluate the composite catalyst's capacity to reduce pollutants characterized by observable NOX content. The catalysts, synthesized through the sol-gel processing technique, are characterized by XRD and SEM to ascertain their suitability for catalytic applications. A comprehensive analysis concludes that the laboratory-synthesized samples exhibit acceptable purity, possess a crystalline structure, and hold potential as catalysts.

Recycling the electric arc furnace waste after geopolymerization in bitumen: experimental analyses and LCA study

The conversion of solid waste materials into cleaner products for road paving. applications appears to be a promising and sustainable option. However, there is still a lack of attention given to quantifying the potential environmental benefits of recycling solid wastes in asphalt pavements, regarding the impact on asphalt performance. To address this gap, the present study investigates the effects of recycling electric arc waste based geopolymers on asphalt binder and mixture characteristics, as well as environmental outputs. For this purpose, geopolymers were incorporated into both neat and SBS-modified binders. A comprehensive rheological investigation was conducted using cutting-edge multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) analyses. Stability, Marshall quotient, and flow values, as well as dry and wetconditioned tensile strength were considered, to determine asphalt mixture properties. In the Life Cycle Assessment (LCA), greenhouse gases resulting from fuel and energy consumption in each inventory phase were determined. The varying service lifetimes, maintenance and rehabilitation plans, and production and construction requirements of the different asphalt schemes were taken into account. Subsequently, the environmental impacts of the asphalt mixtures, including global warming potential, acidification, eutrophication, and smog formation potential, along with the total energy demand, were calculated across different stages of the LCA. The results show that the geopolymerization process results in important contributions in terms of both environmental savings and pavement performance.

Technical, economic, and environmental feasibility assessment of solar-battery-generator hybrid energy systems: a case study in Nigeria

Supermarkets in Nigeria rely on diesel generators for electricity due to the unreliability of the national grid. The recent removal of petroleum subsidies in 2023 has increased fuel prices by 60%. This research examines the technical, economic, and environmental viability of employing solar PV/battery storage/generator systems to generate electricity for high-load supermarkets. The case study was conducted in the Market Square (MS) supermarket in Port Harcourt (PH) city, Nigeria. The MS supermarket had a load demand of 59.8 kW/day for an energy audit in 2022. The average solar radiation and temperature for PH city were 4.21 kWh/m2 and 25.3°C, respectively. The hybrid system was simulated with the HOMER Pro software. The simulation revealed that the optimum baseline (BL) system for the present price of a liter of diesel in Nigeria ($0.63 USD/L) was a solar PV/Battery/Generator. The optimal BL system produced 401,599 kWh/year, which was more than adequate to cover the yearly load requirement of 204,765 kWh/year and left a surplus of 173,195 kWh/year. The BL system had a levelized cost of electricity of $0.106 USD/kWh, a net present cost of $232,533, and Operation and Maintenance cost of $7,928. When the overall environmental impact of the optimal BL system was assessed, it contributed 10,935 kg CO2-eq/year of global warming potential, 1,611 kg O3-eq/year of smog formation, and 72.2 kg SO2-eq/year of acidification potential to the environment. Sensitivity analysis shows that the BL system could have a net present value of $710,364, a 38% internal rate of return, and a 2-year simple payback period over a 25-year life if the excess energy is sold to the grid. Also, LCOE increases with fuel price or discount rate increase, while CO2 falls as all renewable hybrid system configurations become more advantageous. The potential reduction in CO2 emission in the proposed system highlights the environmental benefits compared to traditional ones. This finding will guide decisions on adopting hybrid energy solutions for supermarkets in Nigeria. This analysis offers crucial insights for energy sector decision-makers seeking to balance reliability, cost-effectiveness, and environmental sustainability in a volatile market.

Hourly near-ground NO2 concentration retrieval from geostationary satellite observations

Abstract. Nitrogen dioxide (NO2) is an important contributor to the formation of acid rain, photochemical smog and aerosol particles, which seriously endangers public health. At present, remote sensing of polar-orbiting satellites is a conventional means to obtain large-scale NO2 distribution, but it cannot capture the rapid change because of long revisit periods. The Advanced Himawari Imager (AHI) on the Himawari-8 geostationary satellite has the advantage of high time resolution, which makes it possible to realize near-real-time atmospheric monitoring. Here, based on the absorption characteristics of NO2 in infrared radiation, hourly near-surface NO2 concentrations are retrieved based on the brightness temperature from AHI and auxiliary information such as meteorology and aerosol. The results of 10-fold cross-validation show that NO2 estimations from satellite are in good agreement with in-situ measurements, and their determination coefficient (R2) can reach 0.79. Due to different emission and atmospheric diffusion conditions at different time, the model performance presents a diurnal variation of high accuracy in the noon and afternoon but low accuracy in the morning. Based on the retrieval dataset, it is found that high NO2 concentrations are mainly concentrated in the densely populated and industrial areas such as the North China area. In addition, NO2 pollution mainly occurs in autumn and winter, and the average NO2 concentration in winter is about 1.63 times that in summer in 2021. This study provides a new insight for satellite retrieval of NO2, which is of great significance for real-time pollution monitoring and public health protection.

Life cycle assessment of green–grey coastal flood protection infrastructure: a case study from New Orleans

The study compared the life cycle environmental impacts of three coastal flood management strategies: grey infrastructure (levee), green–grey infrastructure (levee and oyster reef), and a do-nothing scenario, considering the flood damage of a single flooding event in the absence of protection infrastructure. A case study was adopted from a New Orleans, Louisiana residential area to facilitate the comparison. Hazus software, design guidelines, reports, existing projects, and literature were utilized as foreground data for modelling materials. A process-based life cycle assessment was used to assess environmental impacts. The life cycle environmental impacts included global warming, ozone depletion, acidification, eutrophication, smog formation, resource depletion, ecotoxicity, and various human health effects. The ecoinvent database was used for the selected life cycle unit processes. The mean results show green–grey infrastructure as the most promising strategy across most impact categories, reducing 47% of the greenhouse gas (GHG) emissions compared to the do-nothing strategy. Compared to grey infrastructure, green–grey infrastructure mitigates 13%–15% of the environmental impacts while providing equivalent flood protection. A flooding event with a 100-year recurrence interval in the study area is estimated at 34 million kg of CO2 equivalent per kilometre of shoreline, while grey and green–grey infrastructure mitigating such flooding is estimated to be 21 and 18 million kg, respectively. This study reinforced that coastal flooding environmental impacts are primarily caused by rebuilding damaged houses, especially concrete and structural timber replacement, accounting for 90% of GHG emissions, with only 10% associated with flood debris waste treatment. The asphalt cover of the levee was identified as the primary contributor to environmental impacts in grey infrastructure, accounting for over 75% of GHG emissions during construction. We found that there is an important interplay between grey and green infrastructure and optimizing their designs can offer solutions to sustainable coastal flood protection.

Environmental Sustainability of Building Materials in Turkey: Reference Information Recommendations for European Green Deal Declarations

This study provides weight and normalization reference information for declaring the environmental information of building materials produced and exported in Turkey. Reference information was first determined for the global warming potential based on greenhouse gas (GHG) emissions, which is the subject of the European Union Green Deal Carbon Border Adjustment Mechanism (CBAM). For a more holistic approach, reference information is also recommended for environmental impact categories acidification, air pollution, ecological toxicity, eutrophication, fossil fuel depletion, human health, indoor air quality, land use, ozone depletion, photochemical smog formation, and water depletion, in addition to GHG emissions. Reference information is determined based on the life cycle assessment (LCA) methodology defined in the international standards ISO 14040 and ISO 14044. Semi-structured interviews were held with twenty-one industry stakeholders in Turkey to determine the weight reference values. The results obtained from the semi-structured interviews were combined using the analytic hierarchy process (AHP) method. Normalization reference information was determined by compiling Turkey’s national emission values. The suggested reference information has been tested using a case study. Total environmental impact scores were calculated for floor coverings and exterior wall finishes, including global warming potentials based on GHG emissions, and eleven other environmental impact categories. The findings support the need to use regional reference information in Turkey. The reference information recommended in this study can be used both in declarations within the scope of the EU Green Deal and in other possible environmental impact declarations resulting from building materials.

A Building Information Modeling-Based Life Cycle Assessment of the Embodied Carbon and Environmental Impacts of High-Rise Building Structures: A Case Study

High-rise buildings represent technological, urban, and life-style trends of the modern urban landscape, yet there are limited data regarding their embodied carbon and environmental impacts, particularly when compared to low- or mid-rise buildings. Given that the projected growth of the global urban population by 2050 requires cities with higher density and potentially a greater number of high-rise buildings, it is crucial to develop a clear understanding of the embodied carbon and environmental impacts of high-rise buildings. The primary structural materials used in high-rise buildings are reinforced concrete and structural steel. As of today, over 99% of tall buildings’ structures are built from those two materials. This article utilizes a building information modeling (BIM)-based life cycle assessment (LCA) in Revit and Tally to examine the embodied carbon and environmental impacts of an actual high-rise building structure case study in Chicago that uses a hybrid concrete steel structure. The results show that the embodied carbon and environmental impacts of the high-rise building structure are dominated by the impacts of the product stage in the building’s life cycle and by concrete being the main structural material. Specifically, this study reveals that concrete constitutes a substantial 91% share of the total mass of the building structure, with a 74% contribution to the life cycle global warming potential, 53% to the acidification potential, 74% to the eutrophication potential, 74% to the smog formation potential, and 68% to the non-renewable energy usage. On the other hand, steel accounts for 9% of the building’s structure mass, estimated to constitute 26% of the global warming potential, 47% of the acidification potential, 26% of the eutrophication potential, 26% of the smog formation potential, and 32% of the non-renewable energy usage.

A comparative assessment of air pollutants of smog in wagah border and other sites in Lahore, Pakistan.

Smog has become the fifth season of Pakistan especially in Lahore city. Increased level of air pollutants (primary and secondary) are thought to be responsible for the formation of smog in Lahore. Therefore, the current study was carried out for the evaluation of air pollutants (primary and secondary) of smog in Wagah border particularly and other sites (Jail road, Gulburg) Lahore. For this purpose, baseline data on winter smog from March to December on primary and secondary air pollutants and meteorological parameters was collected from Environmental Protection Department and Pakistan Meteorological Department respectively. Devices being used in both departments for analysis of parameters were also studied. Collected data was further statistically analyzed to determine the correlation of parameters with meteorological conditions and was subjected to air quality index. According to results, PM 10 and PM 2.5 were found very high above the NEQS. NOx concentrations were also high above the permissible limits whereas SO2 and O3 were found below the NEQS thus have no roles in smog formation. Air Quality Index (AQI) of pollutants was PM 2.5(86-227), PM 10 (46-332), NOx (26-110), O3 (19-84) and SO2 (10-95). AQI of PM 2.5 remained between moderate to very unhealthy levels. AQI of PM 10 remained between good to hazardous levels. AQI of NOx remained between good to unhealthy for sensitive groups' levels. AQI of O3 and SO2 remained between good to moderate levels. Pearson correlation showed that every pollutant has a different relation with different or same parameters in different areas. It is concluded from the present study that particulate matter was much more responsible for smog formation. Although NOx also played role in smog formation. So there is need to reduce sources of particulate matter and NOx specifically in order to reduce smog formation in Lahore.

Remote Sensing of Tropospheric Ozone from Space: Progress and Challenges

Ozone stands out as a crucial trace gas within the Earth’s atmosphere, exerting a substantial influence on climate change and air pollution. Tropospheric ozone plays an important role in the formation of photochemical smog, and its variations are associated with human activities. The utilization of satellite remote sensing technology for tropospheric ozone monitoring enables a quantitative analysis of its global and regional spatiotemporal characteristics. It also facilitates the investigation of the mechanisms involved in ozone formation within the troposphere. The significant progress in product accuracy and spatiotemporal resolution of ozone remote sensing products, including total ozone and vertical profiles, can be attributed to the extensive development of satellite remote sensing techniques. Nevertheless, the precision of tropospheric ozone products remains inadequate for contemporary scientific purposes, primarily because of faint signals in the lower atmosphere, the intricate nature of the underlying surface, and the existence of clouds and aerosols. This study places emphasis on the satellite remote sensing of tropospheric ozone, encompassing a comprehensive review of the advancements in satellite sensors and the characteristics and suitability of various retrieval algorithms. Moreover, this research delves into the possible utilization of satellite remote sensing for the provision of reliable tropospheric ozone observation data on a global and regional level.

Development of modern research methodology atmosphere pollution in Bishkek city based on a mobile ecological laboratory

The work substantiates the need for scientific development to improve environmental pollution in the city of Bishkek. It has been proven that during the autumn-winter period there is increased air pollution from many different sources. It is proposed to use comprehensive scientific research to identify sources of smog formation, its composition and sources of pollution. The presented method allows one to obtain a vast array of information on air pollution. The need has been established to continue comprehensive monitoring of the environmental situation in our city. It is proposed, based on environmental monitoring, to develop certain conclusions and recommendations to reduce the presence of harmful substances in the air, especially with the beginning of the autumn-winter period.

Effect of d-block metals (M = Ti, Zr, Hf) decorated fullerenes M@C60 as sensor nanostructured materials for volatile organic compounds (VOCs): Approach from computational study

Volatile organic compounds (VOCs) are organic substances that readily evaporate into the atmosphere at room temperature, posing a regular exposure risk to humans. These compounds are associated with various environmental issues, including stratospheric ozone layer depletion, ground-level smog formation, climate change, sick building syndrome, plant decay, atmospheric toxicity, and potential carcinogenic effects on human health. In this study, we utilized ab-initio calculations based on density functional theory (DFT) at the B3LYP-GD3(BJ)/Def2-SVP method to examine how the functionalization of C60 fullerene with Ti, Hf, and Zr transition metals affects its sensing capabilities for volatile organic compounds, specifically methylcyclopentane (MCP), propanone (PPN), and benzene (BZN). The maximum adsorption energy of the transition metal decorated nanocages was recorded at 73.689 kcal/mol corresponding to PPN_Zr@C60 in tandem with the least energy gaps indicating higher conductivity of the PPN_Zr@C60 nanocage with the short bond distance of 1.929 Å for (Zr – O) interaction. The adsorption energy value proposes the adsorption of the volatile organic compound on the Ti, Hf, and Zr transition metal decorated C60 fullerene following the order BZN_Hf@C60 < BZN_Ti@C60 < PPN_Zr@C60. The studied systems possess a relatively high desorption time and they follow the increasing trend – BZN_Hf@C60 < MCP_Hf@C60 < MCP_Zr@C60 < MCP_Ti@C60 < PPN_Hf@C60 < BZN_Zr@C60 < BZN_Ti@C60 < PPN_Ti@C60 < PPN_Zr@C60. The results account that Zr@C60 possesses the highest desorption time and adsorption energy, hence more apposite for detecting the studied VOCs. It also divulges in Hf@C60 contains the least desorption time and least adsorption energy, therefore is not suitable for the detection as it basically portrays the least affinity for the adsorbed VOCs molecule. These results indicate that the VOC transition metal functionalized Ti@C60 and the Zr@C60 are excellent sensors for the effective detection and adsorption of volatile organic compounds which may be useful for environmental protection and the safeguard of human health.

Mechanism of Formation of Smog and some Adverse Effect of Smog on Environment and Human Being

Abstract: The formation of smog is a complex chemical process with significant implications for the environment and human health. This phenomenon primarily results from the interplay of various reactants and products, with its origins tracing back to specific sources. The key contributors to photochemical smog include nitrogen oxides, hydrocarbons, and the energy source that drives the reaction—sunlight. Notably, pollutants like nitrogen oxides and hydrocarbons are byproducts of fossil fuel combustion, primarily emitted from coal-fired power plants and various energy production facilities. Additionally, volatile organic compounds (VOCs) are generated when fossil fuels undergo incomplete combustion, as observed in activities like backyard burning and wood-burning stoves. Smog, characterized by a blend of airborne pollutants, poses significant threats to both human well-being and the environment. It can lead to a range of health issues, including respiratory difficulties, asthma exacerbation, heightened susceptibility to lung infections and colds, and eye irritation.

Study on the Biotoxicity, Microbial Degradation and Metabolism, and Solidification of Monoaromatic Hydrocarbons (MACHs)

Monoaromatic hydrocarbons (MACHs), also known as aromatic organic compounds, are a general term for benzene and its derivatives. In a broad sense, monoaromatic hydrocarbons include all aromatic compounds. It can be used as an organic solvent in building decoration materials and is also widely used in other industries such as dye manufacturing, rubber manufacturing, pharmaceutical industry, pesticide industry, etc. Therefore, monoaromatic hydrocarbons are common pollutants emitted by human activities and can be widely detected in human living and living environments. With the development of China's urban economy, the improvement of residents' living standards, and the rapid increase in the number of motor vehicles, the pollution of monoaromatic hydrocarbons has become increasingly severe. Monoaromatic hydrocarbons have strong carcinogenic effects and can directly harm human respiratory, hematopoietic, nervous, reproductive and other system organs. Monoaromatic hydrocarbons also have high photochemical reactivity and are closely related to the formation of photochemical smog and aerosols in the atmosphere. Moreover, monoaromatic hydrocarbons have the characteristics of wide pollution sources, long action time, high pollution concentration, and long release cycle. They have been prioritized by the United States Environmental Protection Agency (USEPA) as pollutants for control, and have also been included in China's "blacklist" of environmental priority pollutants.

Abatement of photochemical smog precursors through complete hydrocarbon oxidation over commercial Pd catalysts under fuel-lean conditions with NO promoting effect

Currently, severe environmental issues have led to a great transition in the automotive industry from internal combustion engine vehicles to electric vehicles, but this transition will take time more than 10 years, which still requires the use of internal combustion engine vehicles. However, these vehicles emit a significant amount of hydrocarbons, in addition to nitrogen oxides (NOx), due to incomplete fuel combustion. They contribute to the formation of photochemical smog when they react with NOx in the presence of sunlight. To effectively remove these hydrocarbons from the exhaust gas of turbo-gasoline engines or diesel engines, we investigated the abatement of propane and iso-pentane, two typical hydrocarbons. In particular, we studied commercial Pd catalysts and revealed how the Pd loading and aging process simulating 4k and 100k mileage affected hydrocarbon abatement abilities, and their phases were identified using characterization technique, including CO chemisorption, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM). We also suggested the reaction pathway for the complete oxidation of propane over Pd catalyst based on the reaction orders of propane and oxygen: Propane adsorbs on O atoms of PdO, and the kinetically relevant C–H bond cleavage step occurs by the interaction with abundant neighboring O atoms of PdO. Finally, the propane and iso-pentane abatement ability of the Pd catalyst aged for 100k mileage were evaluated under realistic exhaust gas conditions, and the effect of each gas component in the realistic exhaust gas was identified; water inhibits the catalytic reaction of hydrocarbons by occupying the active sites, whereas NO catalyzes the hydrocarbon oxidation reaction by either changing the reaction pathway or active sites under fuel-lean conditions. These findings enable us to effectively reduce environmental pollution and facilitate a smoother transition from internal combustion engine vehicles to electric vehicles.