Ozone Emission Research Articles

Characteristics of Ozone Photochemical Reaction and Emission Reduction Strategies in Summer and Autumn in Shangqiu

Recently, ozone （O3） pollution in Shangqiu has become increasingly prominent, especially in summer and autumn, crucially affecting the local environmental air quality. Based on the monitoring data of O3 pollution days from the Environmental Monitoring Station in June and September 2022 （representing summer and autumn） in Shangqiu, an observation-based model （OBM） was used to study the causes and photochemical reaction characteristics of O3 pollution in the city and precursor emission reduction strategies were studied. The observation results indicated that during summer in Shangqiu, the ρ（O3） and O3 daily maximum 8 h moving concentrations [ρ（MDA8-O3）] were 149.7 μg·m-3 and 195.4 μg·m-3, whereas in autumn, ρ（O3） and ρ（MDA8-O3） were 119.8 μg·m-3 and 173.9 μg·m-3, respectively； the O3 concentration in summer was significantly higher than that in autumn. Ozone sensitivity research showed that the generation of O3 in summer and autumn in Shangqiu was controlled by volatile organic compounds （VOCs）. Among them, oxygen-containing volatile organic compounds （OVOCs）, aromatic hydrocarbons, and alkenes contributed the most to the ozone generation potential （OFP） and ·OH reactivity （L·OH）, and the control must have been strengthened. The OBM simulation results indicated that the maximum O3 generation rates in summer and autumn were 23.0×10-9 h-1 and 13.6×10-9 h-1, with maximum net generation rates of 17.4×10-9 h-1 and 10.4×10-9 h-1 and the maximum and maximum net generation rates of O3 in summer were 1.68 times higher than those in autumn, indicating that the photochemical reactions in summer were significantly stronger than those in autumn. Compared with that in summer, the generation of O3 in autumn was greatly influenced by regional inputs from other regions or cities, with a maximum input of 14.2×10-9 h-1. The prevention and control of O3 pollution in the summer and autumn seasons in Shangqiu should mainly focus on controlling VOCs. The reduction ratio of VOCs/nitrogen oxides （NOx） in autumn should be greater than that in summer and the reduction ratios of 3∶1 in summer and 4∶1 in autumn could be adopted for control.

Source Profiles of VOCs for Different Types of Industrial Boilers in Sichuan, China

Seven different types of industrial boilers in Sichuan Province were selected to determine the VOC emission components and the source profiles of VOCs containing 115 components were established using Teflon sampling and GC-MS/FID analysis. The ozone formation potential （OFP） and emission factors of VOCs from different types of industrial boilers were analyzed. The results showed that the VOC components emitted from different types of industrial boilers were different. Oxygenated volatile organic compounds （OVOCs） and halogenated hydrocarbons were the major components of biomass boilers, with a total contribution rate of more than 60%. The primary VOC emission species included dichloromethane, ethylene, acetone, acetaldehyde, acetylene, and toluene. Halogenated hydrocarbons （50.7%） were the chief emission components of coal-fired boilers, followed by aromatic hydrocarbons and OVOCs. Dichloromethane, ethylene, acetaldehyde, ethyl acetate, and benzene hydrocarbon were the major VOC emission species. The emission of alkanes （59.7%） in natural gas boilers was prominent, particularly ethane and isopentane. The OFP values of VOC emissions from coal-fired, biomass, and natural gas industrial boilers were 6.1, 28.7, and 4.7 mg·m-3, respectively. Alkenes were the primary OFP contributors （35.1%-59.5%） in different types of industrial boilers. OVOCs （32.8%） in biomass boilers and aromatic hydrocarbons （43.0%） in coal-fired boilers also contributed significantly to OFP. The VOC emission factors of coal-fired, biomass, and natural gas industrial boilers in Sichuan Province were （17.3 ± 10.7） g·t-1, （90.6 ± 42.1） g·t-1, and 0.10 g·m-3, respectively. The VOC emission level of biomass boilers was higher than that of coal-fired boilers and VOC emission control could not be ignored.

Research on ozone pollution control strategies for urban agglomerations based on ozone formation sensitivity and emission source contributions

Despite recent enhancements in China's anthropogenic emission controls, ozone (O3) concentrations have continuously increased owing to its nature as a secondary pollutant and the complexities of its production and consumption processes. This study quantified the contributions of urban and sectoral cross-emission sources to O3 levels and identified the anthropogenic emission sources requiring targeted control. Moreover, O3 sensitivity tests were conducted to determine optimal reduction ratios for nitrogen oxides (NOx) and volatile organic compounds (VOCs) emissions. The results were used to recommend effective measures for controlling O3 pollution in the Central Plains urban agglomeration (CPUA). The top 35 cities and sectoral cross-emission sources accounted for 80% of the O3 concentrations in the region, indicating the need for prioritized management of these sources. To achieve reductions in O3 concentrations across all cities, it was found that a 10% reduction in total NOx emissions would require a minimum of 18% reduction in VOCs emissions. Our results indicated that the appropriate coordination of reductions in VOCs and NOx emissions reduced the maximum daily 8-h average O3 (MDA8) concentrations in CPUA by 0.14%–4.78%. Enhancing control measures for prioritized emission sources reduced MDA8 concentrations by 0.78%–7.09%. Furthermore, adjusting the production and emission hours of the industrial sector resulted in a decrease in MDA8 concentrations by 1.10%–12.62%. Overall, our findings indicate that appropriately coordinated reduction of precursor emissions can reduce O3 levels. Further efforts to mitigate O3 pollution should include optimizing the timing of emissions from the industrial sector and other major sources of VOCs emissions.

Characterization and effectiveness of a miniaturized dielectric barrier discharge module for air disinfection

Effective inactivation of airborne pathogens is crucial for air quality control and the prevention of infectious diseases, especially in indoor human-living environments. In this work, a novel air disinfector based on surface dielectric barrier discharge (DBD) plasma was proposed. The discharge characteristics and the disinfection performance of the disinfector were investigated under different applied voltages, airflow rates, and humidity. The used DBD mainly works in the O3-dominant product mode with a discharge power of 1–3 W. The decreases in N2(C-B) emission intensity, ozone, discharge power, and discharge current with the increasing airflow humidity were observed. Humidity was found to be the most pronounced factor promoting the single-pass disinfection efficiency. The Z value reached 0.32 l/J for relative humidity of 70%–80%. Additionally, ozone and ions were found to play a minor role in plasma-mediated bacterial inactivation. The antibacterial effectiveness of the disinfector was also validated by 2-h circulating disinfection experiments. Efficiency was maintained above the disinfection level (>99.9%) after a 5000-h continuous running. Meanwhile, the ozone emission was below the standard limit requirements. The proposed air disinfector is promising for household use with the advantages of small size, bacterial inactivation capability, low ozone emission, and high perceptibility.

The joint impact of PM2.5, O3, and CO2 on the East Asian Summer Monsoon in 2013 and 2018 due to contrasting emission reduction

With the rapid urbanization and the implementation of a series of air pollution control measures, significant changes have occurred in the emission of fine particulate matter (PM2.5), ozone (O3) precursors, and CO2 in China. In this study, we comprehensively assess the impact of emission variations on the East Asian Summer Monsoon (EASM) climate from 2008 to 2018 using a regional-chemistry-ecology model RegCM-Chem-YIBs. The investigations indicated a strengthening of the EASM from 2008 to 2018, with all four EASM Indices exhibiting an increase trend ranging from 0.08 to 1.09 per year based on the simulations. Since 2008, alterations in the emissions of PM2.5 and O3 precursors in 2013 and 2018 led to a rise in near-surface temperatures in China by 0.5–1.5 K, thereby enhancing the EASM. Conversely, the changed CO2 emissions, through its influence on radiative balance and altering BVOCs (Biogenic Volatile Organic Compounds) emissions via its effect on vegetation growth, decreased temperatures by 0.5–1.5 K, thus weakening the EASM. However, when considering the combined effects of total emissions changes in PM2.5, O3 precursors, and CO2, surface temperatures increased by 0.5–2 K, ultimately strengthening the EASM. In addition, compared to 2013, EASM was strongly enhanced in 2018 due to the notable increase in CO2 and significant reduction of PM2.5 and O3 precursors. Our study underscores the significant influence of variations in PM2.5, O3 precursors, and CO2 emissions on EASM climate and emphasizes the importance of coordinated governance of air pollution and climate change.

Localization of Partial Discharges in Hydrogenerators by Ozone Emission

Localization of Partial Discharges in Hydrogenerators by Ozone Emission

Observation-Based Diagnostics of Reactive Nitrogen Recycling through HONO Heterogenous Production: Divergent Implications for Ozone Production and Emission Control.

Understanding of nitrous acid (HONO) production is crucial to photochemical studies, especially in polluted environments like eastern China. In-situ measurements of gaseous and particulate compositions were conducted at a rural coastal site during the 2018 spring Ozone Photochemistry and Export from China Experiment (OPECE). This data set was applied to investigate the recycling of reactive nitrogen through daytime heterogeneous HONO production. Although HONO levels increase during agricultural burning, analysis of the observation data does not indicate more efficient HONO production by agricultural burning aerosols than other anthropogenic aerosols. Box and 1-D modeling analyses reveal the intrinsic relationships between nitrogen dioxide (NO2), particulate nitrate (pNO3), and nitric acid (HNO3), resulting in comparable agreement between observed and simulated HONO concentrations with any one of the three heterogeneous HONO production mechanisms, photosensitized NO2 conversion on aerosols, photolysis of pNO3, and conversion from HNO3. This finding underscores the uncertainties in the mechanistic understanding and quantitative parametrizations of daytime heterogeneous HONO production pathways. Furthermore, the implications for reactive nitrogen recycling, ozone (O3) production, and O3 control strategies vary greatly depending on the HONO production mechanism. On a regional scale, the conversion of HONO from pNO3 can drastically enhance O3 production, while the conversion from NO2 can reduce O3 sensitivity to NOx changes in polluted eastern China.

Degradation of methyl orange using hydrodynamic cavitation coupled with plasma oxidation and ultraviolet C

Combining multiple advanced oxidation processes (AOPs) is essential for the efficient treatment of dye wastewater. In this study, the degradation efficiencies of various oxidation methods, including hydrodynamic cavitation (HC), dielectric barrier discharge (DBD) plasma oxidation, ultraviolet C (UVC), and their combination HC + DBD + UVC, were investigated for Methyl Orange (MO). The photolysis of ozone (O3) and the degradation mechanism associated with HC + DBD + UVC were analyzed to elucidate the pathway of MO degradation. The results demonstrated that the combination of HC + DBD + UVC exhibited a significantly enhanced degradation efficiency compared to other process combinations, achieving a removal efficiency exceeding 91% within a 5-min timeframe. Optimal parameters for achieving a 99.5% degradation rate of 10 mg/L MO were determined as follows: pH 4, inlet pressure of 1.5 MPa, utilization of eight UV lamps with a power input of 46.11 W. During the degradation process, hydroxyl radicals (·OH) and ozone (O3) played crucial roles, while the incorporation of UV lamps effectively mitigated ozone (O3) emissions and enhanced the oxidation of ozone (O3). In conjunction with the analysis of degradation products using liquid chromatography-mass spectrometry, it is highly probable that the MO degradation pathway involves reductive cleavage of the azo bond through ·OH attack. Compared to other experimental methods in literature, HC + DBD + UVC exhibits significant advantages such as enhanced efficiency and absence of additives. This innovative approach offers a rapid and practical on-site solution for efficient MO dye wastewater treatment.

Analysis of electric filters for cleaning the air environment of production premises

RELEVANCE: The problem of hazardous working conditions in Russia attracts attention due to an increase in the proportion of workers exposed to negative impacts on their health. Of particular interest is the analysis of the air environment as the main factor influencing human health. 32.2% of workers in hazardous working conditions are exposed to airborne factors, which leads to occupational diseases. To reduce the harmful effects of the air, it is necessary to clean it from harmful components. A promising device for air purification is an electric precipitator.PURPOSE: The study is aimed at selecting and optimizing electric precipitators for air purification in industrial premises. The goal is to determine the most effective design of an electric precipitator for cleaning the air environment of industrial premises.METHODS: The analysis is carried out on the basis of statistical data, the results of studies of electric precipitators of various designs for cleaning the air from dust, harmful gases and microorganisms. The results are used for comparative analysis.RESULTS: The study reveals that different designs of electrostatic precipitators demonstrate different effectiveness in air purification depending on the type of design. The design of corona electrodes affects ozone generation. It has been established that two-zone electrostatic precipitators with needle corona electrodes on the negative corona can significantly reduce ozone emissions. Wet electrostatic precipitators have regeneration, and the presence of several stages increases the cleaning efficiency. Electrostatic filters do not generate ozone and can be used in explosive low-volume areas.CONCLUSION: The study confirms that the choice of electrostatic precipitator should depend on the specifics of production and the volume of the room. For explosive environments, electrostatic precipitators should be preferred, while for large areas, a wet multi-stage electrostatic precipitator is recommended. Electrostatic precipitators-ozonizers can be effective for air disinfection. Summarizing the results allows us to conclude that it is important to choose the appropriate type of electrostatic precipitator to ensure optimal air conditions for the safety of workers.

Particle removal performance of a novel ESP type air cleaning system for indoor air quality in a subway station

A novel electrostatic precipitation type air cleaning technology with near zero ozone emission for indoor air quality of a subway station was developed. To minimize ozone emission and achieve high particle removal performance against ultrafine particulate matters (PMs), a multi-channel charging method using soft ionization by micrometre carbon fibers and a narrow gap collection method using high electric field by thin conductive plastic sheets as a high voltage electrode were used. In this study, the novel electrostatic charging and collection technologies were applied to a real scale air cleaning system in an Air Handling Unit (AHU) with air flow rate of 950 m3/min in Yuseong Oncheon subway station with an area of 3000 m2 in Daejeon, South Korea. The particle removal performance of the demonstration system was evaluated with real suspended particles in the subway station during test period with high PM concentrations in Korea over 40 μg/m3. Particle collection efficiency, pressure drop and ozone emission were evaluated, and compared to those of the a minimum efficiency reporting value (MERV) 10 and 14 filters used in the typical subway stations in Korea. In the field researches, the developed ESP achieved over 80% of the PM collection efficiency higher than those of the filters with MERV-10 and -14, and even 10% higher efficiency against PM1.0, while generating only 10% of pressure drop and also emitting nearly zero ozone. It is concluded that a novel ESP type air cleaning system with near zero ozone emission could be a promising air cleaning method for a large indoor environment such as a subway station where polluted air with ultrafine particles flowed in with a very high flow rate.

Long-term trajectory of ozone impact on maize and soybean yields in the United States: A 40-year spatial-temporal analysis

Understanding the long-term change trends of ozone-induced yield losses is crucial for formulating strategies to alleviate ozone damaging effects, aiming towards achieving the Zero Hunger Sustainable Development Goal. Despite a wealth of experimental research indicating that ozone's influence on agricultural production exhibits marked fluctuations and differs significantly across various geographical locations, previous studies using global statistical models often failed to capture this spatial-temporal variability, leading to uncertainties in ozone impact estimation. To address this issue, we conducted a comprehensive assessment of the spatial-temporal variability of ozone impacts on maize and soybean yields in the United States (1981–2021) using a geographically and temporally weighted regression (GTWR) model. Our results revealed that over the past four decades, ozone pollution has led to average yield losses of −3.5% for maize and −6.1% for soybean, translating into an annual economic loss of approximately $2.6 billion. Interestingly, despite an overall downward trend in ozone impacts on crop yields following the implementation of stringent ozone emission control measures in 1997, our study identified distinct peaks of abnormally high yield reduction rates in drought years. Significant spatial heterogeneity was detected in ozone impacts across the study area, with ozone damage hotspots located in the Southeast Region and the Mississippi River Basin for maize and soybean, respectively. Furthermore, we discovered that hydrothermal factors modulate crop responses to ozone, with maize showing an inverted U-shaped yield loss trend with temperature increases, while soybean demonstrated an upward trend. Both crops experienced amplified ozone-induced yield losses with rising precipitation. Overall, our study highlights the necessity of incorporating spatiotemporal variability into assessments of crop yield losses attributable to ozone pollution. The insights garnered from our findings can contribute to the formulation of region-specific pollutant emission policies, based on the distinct profiles of ozone-induced agricultural damage across different regions.

THE DIRECT EFFECT OF COMMUNITY-LEVEL RISK FACTORS ON LUNG CANCER INCIDENCE IN FOUR NEW ENGLAND STATES

Abstract Lung cancer is the most common cancer globally and 70% of diagnoses are among the 65+ population. This study identifies what town-level risk factors are contributing to geographic disparities in 65+ lung cancer in N=796 towns in Connecticut, Massachusetts, New Hampshire, and Rhode Island. Multiple spatial-based analyses (e.g., Moran’s I, Getis-Ord Gi*, mapping) were conducted before running a series of spatial regression models to determine the association between town-level risk factors (i.e., environmental exposures, respiratory conditions prevalence, education rates, smoke free legislation) and lung cancer incidence. Mapping and Moran’s I test suggested the 65+ rates of lung cancer in our sample were non-randomly distributed and clusters of high and low rates were present. A hot spot analysis was conducted in ArcMap 10.8 which identified several significant clusters of 65+ lung cancer. Spatial regression models showed that community rates of comorbid respiratory conditions (65+ asthma, COPD, and tobacco use disorder (TUD)) increased lung cancer incidence by 7%, while increasing ozone emissions were directly associated with a 10% increase in incidence. Comprehensive smoke free legislation coverage was significantly associated with lung cancer incidence, but no increasing or decreasing relationship was found. No effects were found for the percentage of 65+ with low education, or 60+ who were current or former smokers. Spatial regression models allow for results which are specific to the geographic sample used and this study suggests that comorbid respiratory conditions and ozone emissions are directly associated with increased rates of 65+ lung cancer incidence in our sample.

Advanced exergy analysis of a Reverse Brayton cycle using air as working fluid for cryogenic purposes

The global push to reduce greenhouse gas emissions has led to the ban of high global warming potential (GWP) refrigerants in the refrigeration sector, prompting the adoption of low-GWP alternatives. However, as regulations are expected to tighten, technologies like the Reverse Brayton cycles (RBC) are emerging. RBCs can operate with safe fluids and can reach very low temperatures through compressions, regeneration, and expansion, requiring only electricity. This research presents results from an RBC equipped with a radial turbine using natural air (R-729), a hazard-free fluid with zero ozone depletion potential (ODP) and emission potential. The cycle utilizes automotive components, offering a cost-effective, high-tech solution. The study evaluates the cycle COP at a design point and performs an exergetic analysis at 173K. Using a thermal and fluid dynamic model of the cycle, the critical components of the cycle influencing the COP are identified, and potential improvements are explored.

The Combined Effects of Hourly Multi-Pollutant on the Risk of Ambulance Emergency Calls: A Seven-Year Time Series Study.

Ambulance emergency calls (AECs) are seen as a more suitable metric for syndromic surveillance due to their heightened sensitivity in reflecting the health impacts of air pollutants. Limited evidence has emphasized the combined effect of hourly air pollutants on AECs. This study aims to investigate the combined effects of multipollutants (i.e., PM2.5, PM10, Ozone, NO2, and SO2) on all-cause and cause-specific AECs by using the quantile g-computation method. We used ambulance emergency dispatch data, air pollutant data, and meteorological data from between 1 January 2013 and 31 December 2019 in Shenzhen, China, to estimate the associations of hourly multipollutants with AECs. We followed a two-stage analytic protocol, including the distributed lag nonlinear model, to examine the predominant lag for each air pollutant, as well as the quantile g-computation model to determine the associations of air pollutant mixtures with all-cause and cause-specific AECs. A total of 3,022,164 patients were identified during the study period in Shenzhen. We found that each interquartile range increment in the concentrations of PM2.5, PM10, Ozone, NO2, and SO2 in 0-8 h, 0-8 h, 0-48 h, 0-28 h, and 0-24 h was associated with the highest risk of AECs. Each interquartile range increase in the mixture of air pollutants was significantly associated with a 1.67% (95% CI, 0.12-3.12%) increase in the risk of all-cause AECs, a 1.81% (95% CI, 0.25-3.39%) increase in the risk of vascular AECs, a 1.77% (95% CI, 0.44-3.11%) increase in reproductive AECs, and a 2.12% (95% CI, 0.56-3.71%) increase in AECs due to injuries. We found combined effects of pollutant mixtures associated with an increased risk of AECs across various causes. These findings highlight the importance of targeted policies and interventions to reduce air pollution, particularly for PM, Ozone, and NO2 emissions.

An Outlier Detection Study of Ozone in Kolkata India by the Classical Statistics, Statistical Process Control and Functional Data Analysis

Air pollution is prevalent throughout the entire world due to the release of various gases such as NOx, PM, SO2, tropospheric ozone (O3), etc. Ground-stage ozone is the predominant issue in smog and is the product of the interplay between sunlight and emissions. The destructive impact on the health of the populace might also still occur in cities with noticeably clean air and where ozone levels hardly ever exceed safe limits. Therefore, the findings of small variations in air quality and the technique of regulating air contamination are thought-provoking. The study employs various techniques to effectively observe and assess strategies for detecting and eliminating outliers in ozone emissions from pollution episodes. This technique helps to describe the sources and exceedance values and enhance the value of monitoring the data. In this study, the data have some missing observations. The method of imputation, the classical statistical technique, the statistical process control (SPC) technique, functional data analysis (FDA), and functional process control help to fill in the data and detect outliers, trend deviations, and changes in ozone concentration at ground level. A comparison study is carried out using these three techniques: classical analysis, SPC, and FDA, and the results show how the statistical process control and functional data methods performed better than the classical technique for the detection of outliers and also in what way this methodology can enable an additional, comprehensive method of defining air pollution control measures and water pollution control measures.

Production of activated carbon by lithium activation and determination of hydrogen storage capacity

The main reason for environmental problems is the ever-increasing demand for energy. Hydrogen in combustion products; does not have side effects such as the greenhouse effect, hole formation in the ozone layer, acid rain, or emission pollutants. Today, hydrogen is the most crucial alternative energy carrier, with the potential to replace fossil fuel mechanisms compared to other systems. In this study, two pyrolysed tree species (pine and beech) from various regions of Kastamonu Province were used as raw materials to store hydrogen. Nitric acid and Lithium chloride were used as activating agents, and their surface areas were compared by obtaining activated carbon at different temperatures. Hydrogen storage capacities were observed that the highest hydrogen adsorption occurs with activated carbon obtained from the activation of 1.39% (w/w) pine sawdust with LiOH at 900 °C at approximately 12 bar pressure. Hydrogen adsorption increased with increasing pressure. It is seen in studies that the amount of hydrogen stored at 77 K is much higher. For this reason, it is more advantageous to conduct investigations at low temperatures, such as cryogenic temperatures, rather than high ones.

A Comparative Assessment of the Some Commercially Available Portable Bipolar Air Ionizers Particulate Pollutants (PM2.5, PM10) Removal Efficacies and Potential Byproduct Ozone Emission

Indoor air cleaning interventions such as bipolar air ionizers have increased lately due to rampant air pollution and the COVID-19 pandemic. Hitherto, the bipolar air ionizer efficacy against particulate pollutants and byproduct ozone emission has not been fully understood and remained a critical concern. Currently, available diverse and complex methods are insufficient to determine commercially available bipolar air ionizer reliability. The National and International market of bipolar air ionizers is proliferating, while safety standards and information are comparatively limited, in such cases, any misleading information by manufacturers could be detrimental to consumers. To focus on those gaps, the present study comprised five different types of commercially available bipolar air ionizers labeled as BAI 1, BAI2, BAI3, BAI4, and BAI5, which were examined against the most concerned indoor particulate pollutants and potential byproduct ozone. Seven days of consecutive experiments were performed in five acrylic boxes, each box assembled with a testing bipolar ionizer model, calibrated air quality monitor, and particulate pollutant source (incense sticks). Two runs/day for each individual bipolar ionizer were performed for up to seven consecutive days. Overall performance was procured from the daily cumulative arithmetic average. All tested bipolar air ionizers models showed notable, up to 80% particulate matter (PM2.5 and PM10) removal efficiencies. The highest particulate matter removal was associated with bipolar air ionizers model 4 (PM10 79.7%, PM2.5 80.4%) and the minimum with BAI model 5 (PM10 72.2%, PM2.5 72.3%). Abnormal ozone emission was not observed with any bipolar air ionizer conduction in this study. Almost negligible elevation in background temperature (0.4 °C) and relative humidity (0.6%) were also observed. In conclusion, bipolar air ionizers could be byproduct ozone-free, indoor particulate matter removal, and low maintenance indoor air cleaning option.

Impact of oxygenated fuels on atmospheric emissions in major Colombian cities

The use of oxygenated gasolines has increased in Latin America over the past several years with the goal to reduce oil dependence, improve gasoline combustion and emit fewer pollutants to the atmosphere. Countries such as Brazil, Colombia, Mexico, Argentina, and Peru blend their gasoline with ethanol in different proportions. In Colombia, the regulation establishes a 10% vol of ethanol in gasoline (E10). Ethers are also used to oxygenate gasolines. MTBE (methyl tert-butyl ether) is blended in gasoline primarily in Mexico, Venezuela, and Chile, while ETBE (ethyl tertiary-butyl ether) is used in Argentina. The U.S. EPA Motor Vehicle Emissions Simulator (MOVES) model was adapted to Colombia to evaluate gasoline blends with two renewable oxygenates (ethanol and ETBE) on the emission of criteria pollutants (PM2.5, CO, NOx, SO2), Total Gaseous Hydrocarbons (TGH), Volatile Organic Compounds (VOCs), and toxic compounds. We followed the same approach used to build MOVES-Mexico and assess fuel specifications changes on vehicle emissions.The MOVES-Colombia model finds that E10 increases fuel volatility, VOCs, NOx, PM2.5, and SO2 emissions, and decreases CO relative to the unoxygenated base gasoline (E0). The impact of E10 consumption on air quality is due not only to primary pollutants, but also to the emission of ozone and PM2.5 precursors. Compared to E10 and E0, the ETBE blends reduce fuel volatility and emissions of VOCs, TGH, CO, NOx, PM2.5, and SO2. The introduction of ETBE could help major urban areas to meet air quality standards even with their current vehicle fleets. This work highlights that the effect of new fuel specifications needs to be properly assessed in terms of air quality before they are put in place. The development of modeling tools, such as MOVES-Colombia, facilitates the study of fuel quality and vehicle technology on pollutant emissions.

Non-thermal plasma coupled with a wet scrubber for removing odorous VOC

Odorous volatile organic compounds (VOCs) deteriorate the quality of life and affect human health. In this study, a process was developed to remove an odorous VOC using a combined non-thermal plasma (NTP) and wet scrubber (WS) system. The low removal efficiency of WSs and the large amount of ozone generated by NTP were resolved. Compared to the decomposition effects when using a WS and NTP separately, the NTP + WS system improved the removal efficiency of ethyl acrylate (EA) and significantly reduced ozone emissions. The maximum EA removal efficiency was 99.9%. Additionally, an EA removal efficiency of over 53.4% and a 100% ozone removal efficiency were achieved even at discharge voltages lower than 4.5 kV. Ozone catalysis was confirmed to occur in the NTP + WS system. Furthermore, we verified the removal of by-products such as residual ozone and formaldehyde, which is a representative organic intermediate of EA. This study demonstrates that the NTP + WS system is a green technology for removing odorous VOCs.

Regression-based Analysis of Ozone Layer via Machine Learning Models

Ozone protects the livings on the earth from ultraviolet radiation. The emission of ozone depleting substance causes the Antarctic ozone hole and reduces the ultraviolet radiation absorption rate by ozone layer. Researchers find that ozone depleting substances (ODS) accounts for ozone concentration between 9 km and 25km, by chemical-climate models and ozone concentration will increase by 15% until 2050. In this work, we used six major ODS consumption worldwide and mean stratospheric ozone concentration each year. Seven regression models are implemented to make prediction and k-fold cross validation is used for avoiding overfitting. Root mean squared error (RMSE), and standard deviation are two performance metrics of regression models. The results indicate that the prediction from support vector regression achieved the lowest RMSE. Random forester and k-nearest neighbor are also appropriate for make prediction. We also concluded that linear, polynomial, ridge, and lasso regression methods are hardly to fit the data in this application.