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Lo, J. C. F., A. K. H. Lau, Z. B. Yuan, J. C. H. Fung und F. Chen. „A physical modeling approach for identification of source regions of primary and secondary air pollutants“. Atmospheric Chemistry and Physics Discussions 6, Nr. 4 (13.07.2006): 6467–96. http://dx.doi.org/10.5194/acpd-6-6467-2006.
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Abstract. This paper describes a simple but practical methodology to identify the contribution of primary and secondary air pollutants from the local/regional emission sources to Hong Kong, a highly urbanized city with complex terrain and coastlines. The meteorological model MM5 coupled with a three-dimensional, mutli-particle trajectory model is used to identify salient aspects of regional air pollutant transport characteristics during some typical meteorological conditions over the Pearl River Delta (PRD) region. Several weighting factors are determined for calculating the air mass/pollutant trajectory and are used to evaluate the local and regional contribution of primary pollutants over the PRD to Hong Kong pollution. The relationships between emission inventories, physical paths and chemical transformation rates of the pollutants, and observational measurements are formulated. The local and regional contributions of secondary pollutants are obtained by this conceptual module under different weather scenarios. Our results demonstrate that major pollution sources over Hong Kong come from regional transport. In calm-weather situations, 78% of the respirable suspended particulates (RSP) totals in Hong Kong are contributed by regional transport, and 49% are contributed by the power plants within the PRD. In normal-day situations, 71% of the RSP are contributed by regional transport, and 45% are contributed by the power plants.
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Zaytsev, Vadim A. „FEATURES OF SECONDARY AIR POLLUTION DURING CHANGING OF THE TRANSPORT STREAM DENSITY“. Bulletin of the Saint Petersburg State Institute of Technology (Technical University) 61 (2022): 85–91. http://dx.doi.org/10.36807/1998-9849-2022-61-87-85-91.
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The pollution of the urban atmosphere in the area of the direct action of the motorway is considered. A certified environmental impact assessment methodology was used as the master. With its help, the masses of substances – that are primary pollutants – emitted per unit of time are calculated depending on the intensity of the traffic flow. Further, to calculate their concentrations, the dispersion is calculated. In order to determine the concentration of the secondary pollutant, ozone, a mathematical model is proposed. It is a stiff system of differential equations that describes the kinetics of the process of chemical transformation of primary pollutants. To solve it, the Rosenbrock method was applied. The influence of the traffic flow density on the ozone content near the highway is being studied
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Piscia, Roberta, Michela Mazzoni, Roberta Bettinetti, Rossana Caroni, Davide Cicala und Marina Marcella Manca. „Stable Isotope Analysis and Persistent Organic Pollutants in Crustacean Zooplankton: The Role of Size and Seasonality“. Water 11, Nr. 7 (18.07.2019): 1490. http://dx.doi.org/10.3390/w11071490.
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Zooplankton is crucial for the transfer of matter, energy, and pollutants through aquatic food webs. Primary and secondary consumers contribute to the abundance and standing stock biomass, which both vary seasonally. By means of taxa- and size-specific carbon and nitrogen stable isotope analysis, the path of pollutants through zooplankton is traced and seasonal changes are addressed, in an effort to understand pollutant dynamics in the pelagic food web. We analyzed zooplankton plurennial changes in concentration of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane and its relatives (DDTs) and in taxa-specific δ15N signatures in two size fractions, ≥450 µm and ≥850 µm, representative of the major part of zooplankton standing stock biomass and of the fraction to which fish predation is mainly directed, respectively. Our work is aimed at verifying: (1) A link between nitrogen isotopic signatures and pollutant concentrations; (2) the predominance of size versus seasonality for concentration of pollutants; and (3) the contribution of secondary versus primary consumers to carbon and nitrogen isotopic signatures. We found a prevalence of seasonality versus size in pollutant concentrations and isotopic signatures. The taxa-specific δ15N results correlated to pollutant concentrations, by means of taxa contribution to standing stock biomass and δ15N isotopic signatures. This is a step forward to understanding the taxa-specific role in pollutant transfer to planktivores and of zooplankton enrichment in PCBs and DDTs.
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Lanfredi, M., M. Macchiato, M. Ragosta und C. Serio. „Time Correlation Structure in Hourly Concentration Time Series of CO, NOx and O3 in Urban Areas“. Fractals 06, Nr. 02 (Juni 1998): 151–58. http://dx.doi.org/10.1142/s0218348x98000195.
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The timescales which govern urban pollution processes are investigated by analyzing variance spectra and structure functions of observational time series. The range of analyzed scales stretches from one hour to several days. It is shown that characteristic fluctuations of CO, NOx (primary pollutants) and O3 (secondary pollutant) follow a scale invariant law up to timescales of about one day. Scaling exponents indicate the presence of stabilizing feedback mechanisms. Such a scale invariance is broken by the appearance of basic periods which, for primary pollutants, are expressions of traffic dynamics, whereas, for ozone, are closely linked to the diurnal and annual solar cycles.
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Pal, Partha. „Biomonitoring with Special Reference to Visible Damages in Different Plant Species due to Air Pollution - A Review“. International Letters of Natural Sciences 16 (Mai 2014): 32–37. http://dx.doi.org/10.18052/www.scipress.com/ilns.16.32.
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Air pollution is a matter of great concern in the globe. Generally air pollutant generates from industries, automobiles, etc. and the primary pollutants may easily convert to secondary pollutants. Both of these pose serious threat to the plant community viz. crops, vegetables and avenue plant species are depending on the emission pattern, atmospheric transport and leaf uptake and on the plant’s biochemical defense capacity. An impact caused by air pollutants depends not only upon its concentration, but also on the duration (acute and chronic exposure) and combination of air pollutants. Biomonitoring on plant species is an easy tool to know bioindicator species in which exposure of air pollutants can easily be identified. The present review deals with past and present research works of major gaseous pollutants emissions and their impact on crop, vegetables and tree species performance from available literatures.
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Pal, Partha. „Biomonitoring with Special Reference to Visible Damages in Different Plant Species due to Air Pollution - A Review“. International Letters of Natural Sciences 16 (30.05.2014): 32–37. http://dx.doi.org/10.56431/p-d10565.
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Air pollution is a matter of great concern in the globe. Generally air pollutant generates from industries, automobiles, etc. and the primary pollutants may easily convert to secondary pollutants. Both of these pose serious threat to the plant community viz. crops, vegetables and avenue plant species are depending on the emission pattern, atmospheric transport and leaf uptake and on the plant’s biochemical defense capacity. An impact caused by air pollutants depends not only upon its concentration, but also on the duration (acute and chronic exposure) and combination of air pollutants. Biomonitoring on plant species is an easy tool to know bioindicator species in which exposure of air pollutants can easily be identified. The present review deals with past and present research works of major gaseous pollutants emissions and their impact on crop, vegetables and tree species performance from available literatures.
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Schäfer, K., M. Elsasser, J. M. Arteaga-Salas, J. Gu, M. Pitz, J. Schnelle-Kreis, J. Cyrys, S. Emeis, A. S. H. Prevot und R. Zimmermann. „Source apportionment and the role of meteorological conditions in the assessment of air pollution exposure due to urban emissions“. Atmospheric Chemistry and Physics Discussions 14, Nr. 2 (24.01.2014): 2235–75. http://dx.doi.org/10.5194/acpd-14-2235-2014.
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Abstract. As particulate matter (PM) impacts human health, knowledge about its composition, exposure and source apportionment is required. A study of the urban atmosphere in the case of Augsburg, Germany, during winter (31 January–12 March 2010) is thus presented here. Investigations were performed on the basis of aerosol mass spectrometry and further air pollutants and meteorological measurements, including mixing layer height. Organic matter was separated by source apportionment of PM1 with positive matrix factorization (PMF) in three factors: OOA – oxygenated organic aerosol (secondary organic factor), HOA – hydrocarbon-like organic aerosol (traffic factor or primary organic factor) and WCOA – wood combustion organic aerosol (wood combustion factor), which extend the information from black carbon (BC) measurements. PMF was also applied to the particle size distribution (PSD) data of PM2.5 to determine different source profiles and we assigned them to the particle sources: nucleation aerosol, fresh traffic aerosol, aged traffic aerosol, stationary combustion aerosol and secondary aerosol. Ten different temporal phases were identified on the basis of weather characteristics and aerosol composition and used for correlations of all air pollutants and meteorological parameters. While source apportionment from both organic PM composition and PSD agree and show that the main emission sources of PM exposure are road traffic as well as stationary and wood combustion, secondary aerosol factor concentrations are very often the highest ones. The hierarchical clustering analysis with the Ward method of cross-correlations of each air pollutant and PM component and of the correlations of each pollutant with all meteorological parameters provided two clusters: "secondary pollutants of PM1 and fine particles" and "primary pollutants (including CO and benzene) and accumulation mode particles". The dominant meteorological influences on pollutant concentrations are wind speed and mixing layer height which are coupled with a certain wind direction. The compounds of the cluster "secondary pollutants and fine particles" show a negative correlation with absolute humidity, i.e., low concentrations during high absolute humidity and vice versa. The PM10 limit value exceedances originated not only from the emissions but also in combination with specific meteorological conditions. NC3-10 (number concentration of nucleation mode particles) and NC10-30 (Aitken mode particles), i.e., ultrafine particles and the fresh traffic aerosol, are only weakly dependent on meteorological parameters and thus are driven by emissions. The results of this case study provide information about chemical composition and causes of PM exposure during winter time in urban air pollution.
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Xue, Wei, Qingming Zhan, Qi Zhang und Zhonghua Wu. „Spatiotemporal Variations of Particulate and Gaseous Pollutants and Their Relations to Meteorological Parameters: The Case of Xiangyang, China“. International Journal of Environmental Research and Public Health 17, Nr. 1 (24.12.2019): 136. http://dx.doi.org/10.3390/ijerph17010136.
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High air pollution levels have become a nationwide problem in China, but limited attention has been paid to prefecture-level cities. Furthermore, different time resolutions between air pollutant level data and meteorological parameters used in many previous studies can lead to biased results. Supported by synchronous measurements of air pollutants and meteorological parameters, including PM2.5, PM10, total suspended particles (TSP), CO, NO2, O3, SO2, temperature, relative humidity, wind speed and direction, at 16 urban sites in Xiangyang, China, from 1 March 2018 to 28 February 2019, this paper: (1) analyzes the overall air quality using an air quality index (AQI); (2) captures spatial dynamics of air pollutants with pollution point source data; (3) characterizes pollution variations at seasonal, day-of-week and diurnal timescales; (4) detects weekend effects and holiday (Chinese New Year and National Day holidays) effects from a statistical point of view; (5) establishes relationships between air pollutants and meteorological parameters. The principal results are as follows: (1) PM2.5 and PM10 act as primary pollutants all year round and O3 loses its primary pollutant position after November; (2) automobile manufacture contributes to more particulate pollutants while chemical plants produce more gaseous pollutants. TSP concentration is related to on-going construction and road sprinkler operations help alleviate it; (3) an unclear weekend effect for all air pollutants is confirmed; (4) celebration activities for the Chinese New Year bring distinctly increased concentrations of SO2 and thereby enhance secondary particulate pollutants; (5) relative humidity and wind speed, respectively, have strong negative correlations with coarse particles and fine particles. Temperature positively correlates with O3.
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Singh, Aditya Abha, Rana Eram, Madhoolika Agrawal, Madhoolika Agrawal, Madhoolika Agrawal und Shashi Bhushan Agrawal. „Air Pollution: Sources and its Effects on Humans and Plants“. INTERNATIONAL JOURNAL OF PLANT AND ENVIRONMENT 8, Nr. 01 (06.09.2022): 10–24. http://dx.doi.org/10.18811/ijpen.v8i01.02.
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Pollution of air is among the serious issue that the world is confronting today in developed and developing countries. An escalating numberof automobiles and industries incessantly add toxic gases like SO2, NOx, and particulate matter into the atmosphere. Simultaneously,secondary pollutant tropospheric O3 formed by the reactions of primary pollutant is equally hazardous. Suspension of these contaminantsin air leads to damaging effects on human health and plant productivity and results in the degradation of ecosystems and biodiversity.Human health issues associated with pollutants in air include cardiovascular and respiratory diseases, nervous and reproductive systemdisorders, lowered life expectancy, and mutations. Moreover, air pollutants negatively affect different morphological and physiologicalcharacteristics of the plants. Air pollutants generate reactive oxygen species that negatively affect various physiological pathways inthe plants inducing their anti-oxidative defense system to counteract oxidative stress. Air pollutants are also accountable for injury tovegetation and losses in crop productivity which is an increased cause of concern. Hence considering the air pollution menace, effectiveregulations, policies, and strategies should be developed for good human health, agricultural production, and food security.
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Nazaroff, William W., und Charles J. Weschler. „Cleaning products and air fresheners: exposure to primary and secondary air pollutants“. Atmospheric Environment 38, Nr. 18 (Juni 2004): 2841–65. http://dx.doi.org/10.1016/j.atmosenv.2004.02.040.
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Ganjar Samudro und Sarwoko Mangkoedihardjo. „Phytoreactor for Arsenic Biodetoxification: An Integrated Sequential Process of Phytoremediation Involving Multi-Kingdom Organisms“. Journal of Advanced Research in Applied Sciences and Engineering Technology 36, Nr. 2 (30.12.2023): 21–35. http://dx.doi.org/10.37934/araset.36.2.2135.
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Phytoremediation of polluted environments has received attention and developed rapidly in recent decades. Plant performance assessment is conducted around the effectiveness and efficiency of reducing the concentration of pollutants and certain plant-associated organisms. While supporting these advances, this paper aims to develop integrated phytoremediation as a pollutant treatment reactor involving all processes and multi-kingdoms of organisms, referred to as phytoreactor. The data collected comes from the results of previous studies related to various kinds of phytoremediation processes. Screening and selection of data were based on criteria for differences in plant processes, involvement of various plant-associated organisms, and aesthetics. An arsenic pollutant, one of the most toxic metalloids and ubiquitous, the kingdom’s involvement of plant-associated organisms between aboveground and belowground plant parts. A new perspective in phytoremediation is creating a phytoreactor that integrates three sequential processes. Starting with the containment of toxic pollutants, followed by a primary process consisting of physicochemical and biological processes, and completed by a secondary process in plants, which produces nontoxic environmental media conditions. The primary biological processes are carried out in the rhizosphere and phyllosphere. The involvement of the plant-associated organism kingdom is different in the rhizosphere and phyllosphere due to the suitability of the habitat, the type of pollutant, and the aesthetics of the application of the phytoreactor. Phytoreactor for the remediation of polluted environments involves synergistic multi-kingdoms of plant-associated organisms for specific types of pollutants in the rhizosphere and phyllosphere.
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Liu, Qian, Bingyan Cui und Zhen Liu. „Air Quality Class Prediction Using Machine Learning Methods Based on Monitoring Data and Secondary Modeling“. Atmosphere 15, Nr. 5 (30.04.2024): 553. http://dx.doi.org/10.3390/atmos15050553.
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Addressing the constraints inherent in traditional primary Air Quality Index (AQI) forecasting models and the shortcomings in the exploitation of meteorological data, this research introduces a novel air quality prediction methodology leveraging machine learning and the enhanced modeling of secondary data. The dataset employed encompasses forecast data on primary pollutant concentrations and primary meteorological conditions, alongside actual meteorological observations and pollutant concentration measurements, spanning from 23 July 2020 to 13 July 2021, sourced from long-term air quality projections at various monitoring stations within Jinan, China. Initially, through a rigorous correlation analysis, ten meteorological factors were selected, comprising both measured and forecasted data across five categories each. Subsequently, the significance of these ten factors was assessed and ranked based on their impact on different pollutant concentrations, utilizing a combination of univariate and multivariate significance analyses alongside a random forest approach. Seasonal characteristic analysis highlighted the distinct seasonal impacts of temperature, humidity, air pressure, and general atmospheric conditions on the concentrations of six key air pollutants. The performance evaluation of various machine learning-based classification prediction models revealed the Light Gradient Boosting Machine (LightGBM) classifier as the most effective, achieving an accuracy rate of 97.5% and an F1 score of 93.3%. Furthermore, experimental results for AQI prediction indicated the Long Short-Term Memory (LSTM) model as superior, demonstrating a goodness-of-fit of 91.37% for AQI predictions, 90.46% for O3 predictions, and a perfect fit for the primary pollutant test set. Collectively, these findings affirm the reliability and efficacy of the employed machine learning models in air quality forecasting.
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Oh, Hyeeun, Soojin Kim, Hyekyung Woo und Seunghon Ham. „Associations between Awareness of the Risk of Exposure to Pollutants Occurring at Fire Scenes and Health Beliefs among Metropolitan Firefighters in the Republic of Korea“. International Journal of Environmental Research and Public Health 19, Nr. 14 (21.07.2022): 8860. http://dx.doi.org/10.3390/ijerph19148860.
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Firefighters are repeatedly exposed to various pollutants that occur at fire scenes. There are three levels of exposure: primary exposure to pollutants, secondary exposure to pollutants on personal protective equipment (PPE), and tertiary exposure to contaminated fire stations and fire engines due to pollutants on PPE. Therefore, it is important for firefighters to be aware of the risk of exposure to pollutants and to practice health behaviors such as appropriate PPE management. No clear association has been established in the existing literature between firefighters’ risk perception level and their health beliefs about the health impact of awareness of exposure to hazardous substances at fire scenes. This study aims to evaluate the relationship between awareness of the exposure risk to primary, secondary, and tertiary pollutants and health beliefs. It was designed as a cross-sectional study, in which a web-based survey was conducted from 13 May to 31 May 2021. The analysis was conducted in 1940 firefighters working in the Seoul metropolis who agreed to participate in the research. Participants who perceived susceptibility were likely to be aware of the primary (adjusted odds ratio (AOR) = 2.10, 95% confidence interval (CI) 1.16–3.80), secondary (AOR = 2.77, 95% CI 1.77–4.32), and tertiary (AOR = 2.73, 95% CI 1.85–4.03) exposure risks. Participants who perceived barriers were unlikely to be aware of the risk of exposure to primary (AOR = 0.67, 95% CI 0.49–0.91), secondary (AOR = 0.77, 95% CI 0.61–0.96), and tertiary (AOR = 0.75, 95% CI 0.62–0.91) pollutants. Educational intervention is recommended to improve perceived susceptibility and awareness of the risk of exposure to pollutants and reduce perceived barriers. Consequently, educational intervention is expected to positively impact firefighters’ management of appropriate PPE. We confirmed an association between occupational exposure risk and firefighters’ health beliefs. In the health belief model (HBM), health beliefs that affect health behavior also affect awareness of the exposure risk level. Therefore, an intervention for health beliefs can also be used to raise job-related exposure risk awareness. Regular training on the health impacts of fire scenes is necessary for both newcomers and incumbents to enable firefighters to better recognize the risks of each occupational exposure level. Additionally, laws and regulations are necessary for the removal of harmful substances that contaminate PPE, such as self-contained breathing apparatus (SCBA), during exposure to a fire scene. Our research can be used as a basis for improving fire policies and education programs in the future.
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Pang, Shaoning, Lei Song, Abdolhossein Sarrafzadeh, Guy Coulson, Ian Longley und Gustavo Olivares. „Indoor Emission Sources Detection by Pollutants Interaction Analysis“. Applied Sciences 11, Nr. 16 (17.08.2021): 7542. http://dx.doi.org/10.3390/app11167542.
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This study employs the correlation coefficients technique to support emission sources detection for indoor environments. Unlike existing methods analyzing merely primary pollution, we consider alternatively the secondary pollution (i.e., chemical reactions between pollutants in addition to pollutant level), and calculate intra pollutants correlation coefficients for characterizing and distinguishing emission events. Extensive experiments show that seven major indoor emission sources are identified by the proposed method, including (1) frying canola oil on electric hob, (2) frying olive oil on an electric hob, (3) frying olive oil on a gas hob, (4) spray of household pesticide, (5) lighting a cigarette and allowing it to smoulder, (6) no activities, and (7) venting session. Furthermore, our method improves the detection accuracy by a support vector machine compared to without data filtering and applying typical feature extraction methods such as PCA and LDA.
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JOMANTAS, Giedrius, und Kęstutis BUINEVIČIUS. „The Effect of Mixing Recirculated Flue Gas with Primary or Secondary Air during Biomass Combustion in Grate-Firing Boiler as the Primary Measure for NOx Reduction“. Mechanics 28, Nr. 6 (05.12.2022): 447–54. http://dx.doi.org/10.5755/j02.mech.31475.
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Due to the pollutant regulations of the Directive (EU) 2015/2193, the need to reduce the emissions of pollutant compounds such as NOx is of a great importance for industrial boilers. This study was performed to determine the effect of primary measures in reducing said pollutants by mixing primary or secondary air with FGR and supplying the mixture for combustion. The studies were conducted on low-scale industrial biomass grate-firing furnace and boiler stand of 25 kW. Sunflower husk pellets, shredded pine bark and wood pellets were combusted during these experiments and emissions of NOx in their combustion products were analyzed. The most significant reduction of emissions was achieved by mixing primary air and FGR and supplying it to the primary combustion zone – under the grate. The emissions of NOx were reduced by 29% and 15% for shredded pine bark and sunflower husk pellets respectively. The emissions of shredded pine bark were reduced enough to meet the standards of the EU Directive, unlike those of sunflower husk pellets. The possible ways to reach greater reduction of NOx by using primary measures are implementing staged combustion, supplying pure FGR and/or mixing agriculture waste with fuels containing less N in its composition.
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Rittmann, B. E. „Microbiological Detoxification of Hazardous Organic Contaminants: The Crucial Role of Substrate Interactions“. Water Science and Technology 25, Nr. 11 (01.06.1992): 403–10. http://dx.doi.org/10.2166/wst.1992.0319.
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Microbiological detoxification of hazardous organic pollutants is highly promising, but its reliable implementation requires a sophisticated understanding of several different substrate types and how they interact. This paper carefully defines the substrate types and explains how their interactions affect the bacteria's electron and energy flows, information flow, and degradative activity. For example, primary substrates, which are essential for growth and maintenance of the bacteria, also interact with degradation of specific hazardous pollutants by being inducers, inhibitors, and direct or indirect cosubstrates. The target contaminants, which often are secondary substrates, also have the interactive roles of self-inhibitor, inhibitor of primary-substrate utilization, inducer, and a part of an aggregate primary substrate.
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Avino, Pasquale. „Black Carbon in Atmosphere: Instrumentation, Chemical-Physical Behavior, Human Health Implications“. Atmosphere 13, Nr. 12 (12.12.2022): 2087. http://dx.doi.org/10.3390/atmos13122087.
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Carbonaceous aerosol is the most significant contributor to the particulate matter in the atmosphere. It is composed of a complex mixture of compounds containing carbon atoms and is usually classified into two main fractions: black carbon (BC) and organic carbon (OC). BC is essentially a primary pollutant emitted in particulate form, and its chemical stability excludes chemical transformations during its lifetime in the atmosphere. Therefore, it should be considered a tracer for the long-range transport of anthropogenic air pollution. OC has both primary and secondary origins: primary OC particulate is formed during combustion and emitted mainly as submicron particles, whereas secondary OC particulate originates from gas-to-particle conversion processes. This SI aims to deepen the state of the art on this important topic ranging from theory to the development of new instrumentation useful for this determination, to the chemical–physical problems in the atmosphere, to the health and toxicological implications related to exposure to these pollutants as well as papers showing historical data series both in urban, rural, and remote areas are also appreciated.
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Younas, Fazila, Adnan Mustafa, Zia Ur Rahman Farooqi, Xiukang Wang, Sadia Younas, Waqas Mohy-Ud-Din, Muhammad Ashir Hameed et al. „Current and Emerging Adsorbent Technologies for Wastewater Treatment: Trends, Limitations, and Environmental Implications“. Water 13, Nr. 2 (18.01.2021): 215. http://dx.doi.org/10.3390/w13020215.
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Wastewater generation and treatment is an ever-increasing concern in the current century due to increased urbanization and industrialization. To tackle the situation of increasing environmental hazards, numerous wastewater treatment approaches are used—i.e., physical, chemical, and biological (primary to tertiary treatment) methods. Various treatment techniques being used have the risks of producing secondary pollutants. The most promising technique is the use of different materials as adsorbents that have a higher efficacy in treating wastewater, with a minimal production of secondary pollutants. Biosorption is a key process that is highly efficient and cost-effective. This method majorly uses the adsorption process/mechanism for toxicant removal from wastewater. This review elaborates the major agricultural and non-agricultural materials-based sorbents that have been used with their possible mechanisms of pollutant removal. Moreover, this creates a better understanding of how the efficacy of these sorbents can be enhanced by modification or treatments with other substances. This review also explains the re-usability and mechanisms of the used adsorbents and/or their disposal in a safe and environmentally friendly way, along with highlighting the major research gaps and potential future research directions. Additionally, the cost benefit ratio of adsorbents is elucidated.
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C.A.Ravirajan, S.Praveen, V.B.Pavan und M.Balasubramanian. „DESIGN OF A NOVEL DEVICE TO REDUCE ENGINE EMISSIONS“. International Journal Of Trendy Research In Engineering And Technology 07, Nr. 03 (2023): 01–06. http://dx.doi.org/10.54473/ijtret.2023.7301.
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Air pollution is a threat in which air has adverse effects on humans and the ecosystem. It is caused by substances which may be solid particles, liquid droplets or gases. Pollutants are classified as primary and secondary. Primary pollutants include carbon monoxide and nitrogen oxides from automobile vehicle exhaust and secondary pollutants includes the Sulphur-dioxide released from factories. The aim of the present work is to fabricate a novel device to reduce the emission of harmful gases such as carbon monoxide, CO2, unburnt hydrocarbons, nitrogen oxides (NOX) which are released from the stationary Engines. Nowadays Diesel particulate filters are used in high-end vehicles to reduce the emission and we are using chemical solutions in our project to reduce the harmful gases released from stationary Engines. The chemical solution used in our project is ammonical cuprous chloride and potassium hydroxide and activated charcoal. Activated charcoal is coated on the baffle plates to absorb the carbon content and the heat generated in the combustion chamber and also filter the harmful nitrous and sulfur content produced by the engine.
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Al-Salem, S. M., und A. R. Khan. „Monitoring and Modelling the Trends of Primary and Secondary Air Pollution Precursors: The Case of the State of Kuwait“. International Journal of Chemical Engineering 2010 (2010): 1–12. http://dx.doi.org/10.1155/2010/879836.
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Since the beginning of the industrial revolution, processes of different scales have contributed greatly to the pollution and waste load on the environment. More specifically, airborne pollutants associated with chemical processes have contributed greatly on the ecosystem and populations health. In this communication, we review recent activities and trends of primary and secondary air pollutants in the state of Kuwait, a country associated with petroleum, petrochemical, and other industrial pollution. Trends of pollutants and impact on human health have been studied and categorized based on recent literature. More attention was paid to areas known to researchers as either precursor sensitive (i.e., nitrogen oxides (NOx), volatile organic compounds (VOCs)) or adjacent to upstream- or downstream-related activities. Environmental monitoring and modelling techniques relevant to this study are also reviewed. Two case studies that link recent data with models associated with industrial sectors are also demonstrated, focusing mainly on chemical mass balance (CMB) and Gaussian line source modelling. It is concluded that a number of the monitoring stations and regulations placed by the Kuwait Environment Public Authority (KUEPA) need up-to-date revisions and better network placement, in agreement with previous findings.
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Bessagnet, Bertrand, Laurent Menut, Florian Couvidat, Frédérik Meleux, Guillaume Siour und Sylvain Mailler. „What Can We Expect from Data Assimilation for Air Quality Forecast? Part II: Analysis with a Semi-Real Case“. Journal of Atmospheric and Oceanic Technology 36, Nr. 7 (Juli 2019): 1433–48. http://dx.doi.org/10.1175/jtech-d-18-0117.1.
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AbstractAssimilation of observational data from ground stations and satellites has been identified as a technique to improve air quality model results. This study is an evaluation of the maximum benefit expected from data assimilation in chemical transport models. Various tests are performed under real meteorological conditions; the injection of various subsets of “simulated observational data” at the initial state of a forecasting period is analyzed in terms of benefit on selected criteria. This observation dataset is generated by a simulation with perturbed input data. Several criteria are defined to analyze the simulations leading to the definition of a “tipping time” to compare the behavior of simulations. Assimilating three-dimensional data instead of ground observations clearly adds value to the forecast. For the studied period and considering the expected best favorable data assimilation experiment, the maximum benefit is higher for particulate matter (PM) with tipping times exceeding 80 h; for ozone (O3) the gain is on average around 30 h. Assimilating O3 concentrations with a delta calculated on the first level and propagated over the vertical direction provides better results on O3 mean concentrations when compared with the expected best experiment corresponding to the injection of the O3 “observations” 3D dataset, but for maximum O3 concentrations the opposite behavior is observed. If data assimilation of secondary pollutant concentrations provides an improvement, assimilation of primary pollutant emissions can have beneficial impacts when compared with an assimilation of concentrations, after several days on secondary pollutants like O3 or nitrate concentrations and more quickly for the emitted primary pollutants. An assimilation of ammonia concentrations has slightly better performances on nitrate, ammonium, and PM concentrations relative to the assimilation of nitrogen or sulfur dioxides.
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Wang, T., W. Nie, J. Gao, L. K. Xue, X. M. Gao, X. F. Wang, J. Qiu et al. „Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact“. Atmospheric Chemistry and Physics Discussions 10, Nr. 5 (12.05.2010): 12433–63. http://dx.doi.org/10.5194/acpd-10-12433-2010.
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Abstract. This paper presents the first results of the atmospheric measurements of trace gases and aerosols at three surface sites in and around Beijing before and during the 2008 Olympics. We focus on secondary pollutants including ozone, fine sulfate and nitrate, and the contribution of regional sources in summer 2008. The results reveal different responses of secondary pollutants to the control measures from primary pollutants. Ambient concentrations of vehicle-related nitrogen oxides (NOx) and volatile organic compounds (VOCs) at an urban site dropped by 25% and 20–45% in the first two weeks after full control was put in place, but the levels of ozone, sulfate and nitrate in PM2.5 increased by 16%, 64%, 37%, respectively, compared to the period prior to the full control; wind data and back trajectories indicated the contribution of regional pollution from the North China Plain. Air quality (for both primary and secondary pollutants) improved significantly during the Games, which were also associated with the changes in weather conditions (prolonged rainfall, decreased temperature, and more frequent air masses from clean regions). A comparison of the ozone data at three sites on eight ozone-pollution days, when the air masses were from the southeast-south-southwest sector, showed that regional pollution sources contributed 34%–88% to the peak ozone concentrations in urban Beijing. Ozone production efficiencies at two sites were low (~3 ppbv/ppbv), indicating that ozone formation was being controlled by VOCs. Compared with data collected in 2005 at a downwind site, the concentrations of ozone, sulfur dioxide (SO2), total sulfur (SO2+PM2.5 sulfate), carbon monoxide (CO), reactive aromatics (toluene and xylenes) sharply decreased (by 8–64%) in 2008, but no significant changes were observed for the concentrations of PM2.5, fine sulfate, total odd reactive nitrogen (NOy), and longer lived alkanes and benzene. We suggest that these results indicate the success of the government's efforts in reducing emissions of SO2, CO, and VOCs in Beijing. However, further control of regional emissions is needed for significant reductions of ozone and fine particulate pollution in Beijing.
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Serrato, Denisse Morales, Jonatan Torres Pérez, Álvaro de Jesús Ruíz Baltazar und Simón Yobanny Reyes López. „ADSORBENT MATERIALS FOR EMERGING CONTAMINANT (TETRACYCLINE) REMOVAL“. International Journal of Research -GRANTHAALAYAH 9, Nr. 4 (08.05.2021): 466–91. http://dx.doi.org/10.29121/granthaalayah.v9.i4.2021.3847.
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Water pollution is a serious environmental problem caused by activities. A group of pollutants that are not controlled in the environment but that cause harmful effects on the ecosystem are known as emerging pollutants. One of these groups of emerging pollutants detected in water bodies are pharmaceutical compounds. One of the main problems caused by pharmaceutical compounds as pollutant is bacterial resistance. are a family of antibiotics frequently used. Due to their poor absorption they are released into the environment through feces and urine as active ingredients. Wastewater treatment consists in three stages: primary, secondary, and tertiary treatment. Tertiary treatment employs methods such as reverse osmosis, oxidation-reduction, ultraviolet irradiation, and adsorption. Adsorption is used because it is a simple and effective. For the choice of an effective adsorbent material, surface area, porosity, adsorption capacity, mechanical stability, and factors such as profitability, regeneration, sustainability, and selectivity are considered. In the present review, the adsorbents commonly used in the treatment of water contaminated with were analyzed. The adsorbents used have been classified in a general way as metallic materials, polymers, ceramics, composites, and materials based on biomass.
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Chin, Kyle, Aurelie Laguerre, Pradeep Ramasubramanian, David Pleshakov, Brent Stephens und Elliott T. Gall. „Emerging investigator series: primary emissions, ozone reactivity, and byproduct emissions from building insulation materials“. Environmental Science: Processes & Impacts 21, Nr. 8 (2019): 1255–67. http://dx.doi.org/10.1039/c9em00024k.
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Insulation materials affect indoor air by (i) releasing primary volatile organic compounds (VOCs) from enclosure cavities to the interior space, (ii) mitigating exposure to outdoor pollutants through reactive deposition (of oxidants, e.g., ozone) or filtration in infiltration air, and (iii) generating secondary VOCs and gas-phase byproducts from chemical reactions.
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Cope, M. E., G. D. Hess, S. Lee, K. Tory, M. Azzi, J. Carras, W. Lilley et al. „The Australian Air Quality Forecasting System. Part I: Project Description and Early Outcomes“. Journal of Applied Meteorology 43, Nr. 5 (01.05.2004): 649–62. http://dx.doi.org/10.1175/2093.1.
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Abstract The Australian Air Quality Forecasting System (AAQFS) is the culmination of a 3-yr project to develop a numerical primitive equation system for generating high-resolution (1–5 km) short-term (24–36 h) forecasts for the Australian coastal cities of Melbourne and Sydney. Forecasts are generated 2 times per day for a range of primary and secondary air pollutants, including ozone, nitrogen dioxide, carbon monoxide, sulfur dioxide, and particles that are less than 10 μm in diameter (PM10). A preliminary assessment of system performance has been undertaken using forecasts generated over a 3-month demonstration period. For the priority pollutant ozone it was found that AAQFS achieved a coefficient of determination of 0.65 and 0.57 for forecasts of peak daily 1-h concentration in Melbourne and Sydney, respectively. The probability of detection and false-alarm rate were 0.71 and 0.55, respectively, for a 60-ppb forecast threshold in Melbourne. A similar level of skill was achieved for Sydney. System performance is also promising for the primary gaseous pollutants. Further development is required before the system can be used to forecast PM10 confidently, with a systematic overprediction of 24-h PM10 concentration occurring during the winter months.
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Kelly, Frank J. „Dietary antioxidants and environmental stress“. Proceedings of the Nutrition Society 63, Nr. 4 (November 2004): 579–85. http://dx.doi.org/10.1079/pns2004388.
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Air is one of our most important natural resources; however, it is also in the front line for receiving environmental pollution. Air quality decreased markedly following the industrial revolution, but it was not until the great London Smog in 1952 that air quality made it onto the political agenda. The introduction of the Clean Air Act in 1956 led to dramatic decreases in black smoke and SO2 concentrations over the next two decades, as domestic and industrial coal-burning activities ceased. However, as these improvements progressed, a new threat to public health was being released into the air in ever-increasing quantities. Rapid motorisation of society from the 1960s onwards has led to the increased release of atmospheric pollutants such as tiny particles (particulate matter of &10 μm in aerodynamic diameter) and oxides of N, and the generation of the secondary pollutant O3. These primary and secondary traffic-related pollutants have all proved to be major risks factors to public health. Recently, oxidative stress has been identified as a unifying feature underlying the toxic actions of these pollutants. Fortunately, the surface of the lung is covered with a thin layer of fluid containing a range of antioxidants that appear to provide the first line of defence against oxidant pollutants. As diet is the only source of antioxidant micronutrients, a plausible link now exists between the sensitivity to air pollution and the quality of the food eaten. However, many questions remain unanswered in relation to inter-individual sensitivity to ambient air pollution, and extent to which this sensitivity is modified by airway antioxidant defences.
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Litz, N. „Assessment of organic constituents in sewage sludge“. Water Science and Technology 42, Nr. 9 (01.11.2000): 187–93. http://dx.doi.org/10.2166/wst.2000.0203.
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A standardized evaluation concept based on human toxicity, ecotoxicity and soil related data has been developed for the assessment of pollutants in sewage sludge. This assessment concept for different compounds is applicable using evaluation steps that are comparable and transparent based on a classification system. All compounds assessed here were assigned to three groups: pollutants of primary relevance, pollutants of secondary relevance and such, on which more information is necessary for evaluation. For the purpose of comparing the evaluation concept with results from some investigations under field and laboratory conditions degradation, sorption, retardation and plant transfer data for LAS are presented and discussed.
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Istiqomah, Qolby, Robby Irsan und Agum Satria. „ANALYSIS OF DISTRIBUTION OF NO2 POLLUTANTS IN PT. X SANGGAU REGENCY, WEST KALIMANTAN“. Jurnal Teknik Sipil 23, Nr. 3 (27.08.2023): 359. http://dx.doi.org/10.26418/jts.v23i3.64855.
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Air pollution can come from natural activities and human activities. One type of pollutant that needs attention is air pollution caused by exhaust fumes from engine combustion and air pollution due to machines such as steam power plants. PT. X is a company engaged in the industrial sector that processes bauxite into alumina. PT. X is an example of an industry that uses coal and diesel-fired steam power plants for its factory operations. As a result of the fuel combustion process produces several exhaust gases, one of which is nitrogen dioxide, into the surrounding air. If the flue gas from the chimney exceeds the quality standard, it can pose a risk to workers and the surrounding community. Therefore, research was conducted on analyzing the distribution of NO2 pollutants from chimneys at PT. X. The data used are primary and secondary. The primary data is in the form of NO2 concentration in ambient air, while the secondary data is in wind direction and speed in one year. The known secondary data is then processed using the wrplot application so that the results are obtained in the form of the distribution of NO2 pollutants in the air. Based on the results of wind speed and direction data processing in Figure 1, it can be seen that the dominant wind direction blows from east to west with 699 occurrences, with wind speeds mostly occurring between 3.00 – 4.00 MS. Based on the wind rose above, there is no wind with a speed of less than 0.5 m/s or a calm wind. The minimum speed occurs in the range 1.00 – 2.00 m/s and the maximum speed occurs in the range ≥ 7.00 m/s.
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Lu, Pan, Shunxi Deng, Guanghua Li, Abula Tuheti und Jiayao Liu. „Regional Transport of PM2.5 from Coal-Fired Power Plants in the Fenwei Plain, China“. International Journal of Environmental Research and Public Health 20, Nr. 3 (25.01.2023): 2170. http://dx.doi.org/10.3390/ijerph20032170.
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The Fenwei Plain (FWP) remains one of the worst PM2.5-polluted regions in China, although its air quality has improved in recent years. To evaluate the regional transport characteristics of PM2.5 emitted by coal-fired power plants in the FWP in wintertime, the primary PM2.5, SO2, and NOx emissions from coal-fired power plants with large units (≥ 300 MW) in 11 cities of the area in January 2019 were collected based on the Continuous Emission Monitoring System (CEMS). The spatial distribution and source contribution of primary and secondary PM2.5 concentrations were investigated using the Weather Research and Forecast (WRF) model and the California Puff (CALPUFF) model. The results showed that secondary PM2.5 was transported over a larger range than primary PM2.5 and that secondary nitrate was the main component of the total PM2.5 concentration, accounting for more than 70%. High concentrations of primary, secondary, and total PM2.5 mainly occurred in the Shaanxi region of the FWP, especially in Xianyang, where the PM2.5 concentrations were the highest among the 11 cities, even though its pollutant emissions were at moderate levels. The PM2.5 concentrations in Sanmenxia and Yuncheng primarily came from regional transport, accounting for 64% and 68%, respectively, while those in other cities were dominated by local emissions, accounting for more than 63%. The results may help to understand the regional transport characteristics of pollutants emitted from elevated point sources over a complex terrain.
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Liu, Mengyao, Jintai Lin, Yuchen Wang, Yang Sun, Bo Zheng, Jingyuan Shao, Lulu Chen et al. „Spatiotemporal variability of NO<sub>2</sub> and PM<sub>2.5</sub> over Eastern China: observational and model analyses with a novel statistical method“. Atmospheric Chemistry and Physics 18, Nr. 17 (07.09.2018): 12933–52. http://dx.doi.org/10.5194/acp-18-12933-2018.
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Abstract. Eastern China (27–41∘ N, 110–123∘ E) is heavily polluted by nitrogen dioxide (NO2), particulate matter with aerodynamic diameter below 2.5 µm (PM2.5), and other air pollutants. These pollutants vary on a variety of temporal and spatial scales, with many temporal scales that are nonperiodic and nonstationary, challenging proper quantitative characterization and visualization. This study uses a newly compiled EOF–EEMD analysis visualization package to evaluate the spatiotemporal variability of ground-level NO2, PM2.5, and their associations with meteorological processes over Eastern China in fall–winter 2013. Applying the package to observed hourly pollutant data reveals a primary spatial pattern representing Eastern China synchronous variation in time, which is dominated by diurnal variability with a much weaker day-to-day signal. A secondary spatial mode, representing north–south opposing changes in time with no constant period, is characterized by wind-related dilution or a buildup of pollutants from one day to another. We further evaluate simulations of nested GEOS-Chem v9-02 and WRF/CMAQ v5.0.1 in capturing the spatiotemporal variability of pollutants. GEOS-Chem underestimates NO2 by about 17 µg m−3 and PM2.5 by 35 µg m−3 on average over fall–winter 2013. It reproduces the diurnal variability for both pollutants. For the day-to-day variation, GEOS-Chem reproduces the observed north–south contrasting mode for both pollutants but not the Eastern China synchronous mode (especially for NO2). The model errors are due to a first model layer too thick (about 130 m) to capture the near-surface vertical gradient, deficiencies in the nighttime nitrogen chemistry in the first layer, and missing secondary organic aerosols and anthropogenic dust. CMAQ overestimates the diurnal cycle of pollutants due to too-weak boundary layer mixing, especially in the nighttime, and overestimates NO2 by about 30 µg m−3 and PM2.5 by 60 µg m−3. For the day-to-day variability, CMAQ reproduces the observed Eastern China synchronous mode but not the north–south opposing mode of NO2. Both models capture the day-to-day variability of PM2.5 better than that of NO2. These results shed light on model improvement. The EOF–EEMD package is freely available for noncommercial uses.
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Chai, Zhen, Fu Ping Li und Xu Wen He. „The Environmental Problems in Development and Utilization of Urban Mines: Taking Secondary Copper Production as a Case“. Advanced Materials Research 726-731 (August 2013): 4154–58. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.4154.
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The great amount of resource consumption and the depletion of metal rich primary ores are the main driving forces to develop and utilize the valuable resource hiding in urban mines. Although urban mining possesses several advantages such as lower energy consumption, less cost and easier to develop and less pollution than conventional primary mining, the various wastes generated in the urban mining become a burden for the society because of poor organization production and the implementation of the strict environmental regulations. This paper investigated the environmental problems and the wastes characterization in development and utilization by taking secondary copper as an example. The main pollutants discharged in secondary copper production were exhaust gas containing POPs and metals, waste water of heavy metals and acid water, and the residues of melting and electrolytic plants. The toxic pollutants like heavy metals asked for appropriate dumping and disposal to prevent the damage to the environment.
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Levy, Ilan. „A national day with near zero emissions and its effect on primary and secondary pollutants“. Atmospheric Environment 77 (Oktober 2013): 202–12. http://dx.doi.org/10.1016/j.atmosenv.2013.05.005.
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Ji, Yuanyuan, Cong An, Jinghao Tang, Jialin Li, Xiaoyu Yan, Xiaoshuai Gao, Wanghui Chu et al. „Causes Investigation of PM2.5 and O3 Complex Pollution in a Typical Coastal City in the Bohai Bay Region of China in Autumn: Based on One-Month Continuous Intensive Observation and Model Simulation“. Atmosphere 15, Nr. 1 (07.01.2024): 73. http://dx.doi.org/10.3390/atmos15010073.
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In order to investigate the causes of complex air pollution in coastal cities in the Bohai Rim of China, a one-month intensive field observation combined with model simulation was carried out in a typical city named Dongying in September 2022. The results showed that two PM2.5 and O3 complex pollution episodes occurred in Dongying in the observation period, with the primary pollutant being O3. Atmospheric photochemical reactions occurring under unfavorable meteorological conditions led to the production of O3 while at the same time facilitating the generation of nitrate, sulfate, and other secondary components of PM2.5 by enhancing the atmospheric oxidizing capacity, which promoted the formation of complex air pollution. It was worth noting that in the context of high pollutants emission, the occurrence of complex air pollution was more sensitive to the variation in meteorological conditions than to the change in pollutants emission. To continuously improve air quality and protect human health in Dongying, it is recommended that an effective regional joint air pollution prevention and control mechanism with neighboring cities should be established in the premise of effective local pollutants reduction, and special attention should be paid to the adverse effect of the air mass transportation from Bohai Bay.
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Awang, Norrimi Rosaida, und Soniya Ramesh Kumar. „Diurnal variation of secondary air pollutant concentrations during movement restriction orders in Johor“. BIO Web of Conferences 73 (2023): 05002. http://dx.doi.org/10.1051/bioconf/20237305002.
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Secondary air pollutants are those that are formed through chemical reactions between primary pollutants and other substances in the atmosphere. Diurnal variations in secondary air pollutants can occur due to changes in sunlight, temperature, and the presence of other chemicals in the atmosphere. Ground-level ozone is created when sunlight interacts with nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the air. This study focused on secondary air pollution levels during movement restriction orders (MCOs)using hourly average ozone data acquired from the Department of Environment Malaysia in 2020 and 2021 in Batu Pahat station. The data were analyzed using descriptive statistics, time series analysis, and diurnal plot. The diurnal pattern of ozone concentrations showed a consistent trend in the location, with the highest levels observed from noon to evening and the lowest levels at night. Additionally, the study found that ozone levels were highest during the movement control order (MCOs) compared to the conditional movement control order (CMCO) and restricted movement control order (RMCO) with mean values of 18.1 ppb, 14.5 ppb and 17.4 ppb, respectively due to increased sunlight during the summer months. The study findings can be used to identify and study the best conditions to decrease ozone air pollution.
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Wang, T., W. Nie, J. Gao, L. K. Xue, X. M. Gao, X. F. Wang, J. Qiu et al. „Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact“. Atmospheric Chemistry and Physics 10, Nr. 16 (16.08.2010): 7603–15. http://dx.doi.org/10.5194/acp-10-7603-2010.
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Abstract. This paper presents the first results of the measurements of trace gases and aerosols at three surface sites in and outside Beijing before and during the 2008 Olympics. The official air pollution index near the Olympic Stadium and the data from our nearby site revealed an obvious association between air quality and meteorology and different responses of secondary and primary pollutants to the control measures. Ambient concentrations of vehicle-related nitrogen oxides (NOx) and volatile organic compounds (VOCs) at an urban site dropped by 25% and 20–45% in the first two weeks after full control was put in place, but the levels of ozone, sulfate and nitrate in PM2.5 increased by 16%, 64%, 37%, respectively, compared to the period prior to the full control; wind data and back trajectories indicated the contribution of regional pollution from the North China Plain. Air quality (for both primary and secondary pollutants) improved significantly during the Games, which were also associated with the changes in weather conditions (prolonged rainfall, decreased temperature, and more frequent air masses from clean regions). A comparison of the ozone data at three sites on eight ozone-pollution days, when the air masses were from the southeast-south-southwest sector, showed that regional pollution sources contributed >34–88% to the peak ozone concentrations at the urban site in Beijing. Regional sources also contributed significantly to the CO concentrations in urban Beijing. Ozone production efficiencies at two sites were low (~3 ppbv/ppbv), indicating that ozone formation was being controlled by VOCs. Compared with data collected in 2005 at a downwind site, the concentrations of ozone, sulfur dioxide (SO2), total sulfur (SO2+PM2.5 sulfate), carbon monoxide (CO), reactive aromatics (toluene and xylenes) sharply decreased (by 8–64%) in 2008, but no significant changes were observed for the concentrations of PM2.5, fine sulfate, total odd reactive nitrogen (NOy), and longer lived alkanes and benzene. We suggest that these results indicate the success of the government's efforts in reducing emissions of SO2, CO, and VOCs in Beijing, but increased regional emissions during 2005–2008. More stringent control of regional emissions will be needed for significant reductions of ozone and fine particulate pollution in Beijing.
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Salazar, Cristian, Anna I. Kurbatova und Milana E. Kupriyanova. „Quito’s coronavirus curfew: Escalating tropospheric ozone pollution“. E3S Web of Conferences 211 (2020): 04008. http://dx.doi.org/10.1051/e3sconf/202021104008.
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The effect of the curfew due to the pandemic of Covid-19 virus on the levels of air pollution in the historic center of Quito was evaluated with a focus on tropospheric ozone (O3). During the curfew period the daily O3 mean concentration increased by 96%, 109% and 95% in comparison to the concentrations for the same period in the years 2017, 2018 and 2019. This increase is mainly explained by considerable reduction in NOx emissions, thus there was little titration of ozone accumulated in the city environment due to its shallow boundary layer by NO, reaching its maximum concentration at midday. Among studied pollutants that influence O3 formation (CO, NO2, PM2.5) during the curfew the contaminant that showed the greatest reduction in the mean concentration compared to three previous years was NO2, followed by CO and PM2.5. The daily O3 8-hour mean concentrations during the curfew both on weekdays and weekends were lower than the limit values. These results are relevant for designing abatement policies of secondary pollutants such as O3 under strict measures of control of primary pollutant emissions.
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Rajeswari, Mrs S., V. Manosri, G. Praveen Kumar, C. Sugapriya und S. Udhayakumaran. „Adsorption Study on Waste Water Characteristics by using Natural Bio-Adsorbents“. International Journal for Research in Applied Science and Engineering Technology 11, Nr. 5 (31.05.2023): 3108–11. http://dx.doi.org/10.22214/ijraset.2023.52232.
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Abstract: Wastewater generation and treatment is an ever-increasing concern in the current century due to increased urbanization and industrialization. Hazardous contamination of water is a major hurdle in the provision of usable and drinkable water to the world. Innovative, economic, renewable and environment friendly technologies are need of the hour for wastewater treatment. Numerous wastewater treatment techniques, including physical, chemical, and biological (primary to tertiary treatment) approaches, are used to address the issue of growing environmental hazards. Various treatment techniques being used have the risks of producing secondary pollutants. The most promising technique is the use of different materials as adsorbents that have a higher efficacy in treating wastewater, with a minimal production of secondary pollutants. Adsorption Technology is used for Grey water treatment.
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Lu, Keding, Song Guo, Zhaofeng Tan, Haichao Wang, Dongjie Shang, Yuhan Liu, Xin Li, Zhijun Wu, Min Hu und Yuanhang Zhang. „Exploring atmospheric free-radical chemistry in China: the self-cleansing capacity and the formation of secondary air pollution“. National Science Review 6, Nr. 3 (19.07.2018): 579–94. http://dx.doi.org/10.1093/nsr/nwy073.
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Abstract Since 1971, it has been known that the atmospheric free radicals play a pivotal role in maintaining the oxidizing power of the troposphere. The existence of the oxidizing power is an important feature of the troposphere to remove primary air pollutants emitted from human beings as well as those from the biosphere. Nevertheless, serious secondary air-pollution incidents can take place due to fast oxidation of the primary pollutants. Elucidating the atmospheric free-radical chemistry is a demanding task in the field of atmospheric chemistry worldwide, which includes two kinds of work: first, the setup of reliable radical detection systems; second, integrated field studies that enable closure studies on the sources and sinks of targeted radicals such as OH and NO3. In this review, we try to review the Chinese efforts to explore the atmospheric free-radical chemistry in such chemical complex environments and the possible link of this fast gas-phase oxidation with the fast formation of secondary air pollution in the city-cluster areas in China.
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Amato, F., M. Viana, A. Richard, M. Furger, A. S. H. Prevot, S. Nava, F. Lucarelli et al. „Size and time-resolved roadside enrichment of atmospheric particulate pollutants“. Atmospheric Chemistry and Physics Discussions 11, Nr. 1 (07.01.2011): 453–83. http://dx.doi.org/10.5194/acpd-11-453-2011.
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Abstract. Size and time-resolved roadside enrichments of atmospheric particulate pollutants in PM10 were detected and quantified in a Mediterranean urban environment (Barcelona, Spain). Simultaneous data from one urban background (UB), one traffic (T) and one heavy traffic (HT) location were analysed, and roadside PM10 enrichments (RE) in a number of elements arising from vehicular emissions were calculated. Tracers of primary traffic emissions (EC, Fe, Ba, Cu, Sb, Cr, Sn) showed the largest REs (>70%). Other traffic tracers (Zr, Cd) showed lower but still consistent REs (25–40%), similar to those obtained for mineral matter resulting from road dust resuspension (Ca, La, Ce, Ti, Ga, Sr, 30–40%). The sum of primary and secondary organic carbon showed a RE of 41%, with contributions of secondary OC (SOC) to total OC ranging from 46% at the HT site, 63% at the T site, and 78% in the UB. Finally, other trace elements (As, Co, Bi) showed unexpected but consistent roadside enrichments (23% up to 69%), suggesting a link to traffic emissions even though the emission process is unclear. Hourly-resolved PM speciation data proved to be a highly resourceful tool to determine the source origin of atmospheric pollutants in urban environments. At the HT site, up to 62% of fine Mn was attributable to industrial plumes, whereas coarse Mn levels were mainly attributed to traffic. Similarly, even though Zn showed on average no roadside enrichment and thus was classified as industrial, the hourly-resolved data proved that at least 15% of coarse Zn may be attributed to road traffic emissions. In addition, our results indicate that secondary nitrate formation occurs within the city-scale, even in the absence of long atmospheric residence times or long-range atmospheric transport processes.
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Amato, F., M. Viana, A. Richard, M. Furger, A. S. H. Prévôt, S. Nava, F. Lucarelli et al. „Size and time-resolved roadside enrichment of atmospheric particulate pollutants“. Atmospheric Chemistry and Physics 11, Nr. 6 (29.03.2011): 2917–31. http://dx.doi.org/10.5194/acp-11-2917-2011.
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Abstract. Size and time-resolved roadside enrichments of atmospheric particulate pollutants in PM10 were detected and quantified in a Mediterranean urban environment (Barcelona, Spain). Simultaneous data from one urban background (UB), one traffic (T) and one heavy traffic (HT) location were analysed, and roadside PM10 enrichments (RE) in a number of elements arising from vehicular emissions were calculated. Tracers of primary traffic emissions (EC, Fe, Ba, Cu, Sb, Cr, Sn) showed the largest REs (>70%). Other traffic tracers (Zr, Cd) showed lower but still consistent REs (25–40%), similar to those obtained for mineral matter resulting from road dust resuspension (Ca, La, Ce, Ti, Ga, Sr, 30–40%). The sum of primary and secondary organic carbon showed a RE of 41%, with contributions of secondary OC (SOC) to total OC ranging from 46% at the HT site, 63% at the T site, and 78% in the UB. Finally, other trace elements (As, Co, Bi) showed unexpected but consistent roadside enrichments (23% up to 69%), suggesting a link to traffic emissions even though the emission process is unclear. Hourly-resolved PM speciation data proved to be a highly resourceful tool to determine the source origin of atmospheric pollutants in urban environments. At the HT site, up to 62% of fine Mn was attributable to industrial plumes, whereas coarse Mn levels were mainly attributed to traffic. Similarly, even though Zn showed on average no roadside enrichment and thus was classified as industrial, the hourly-resolved data proved that at least 15% of coarse Zn may be attributed to road traffic emissions. In addition, our results indicate that secondary nitrate formation occurs within the city-scale, even in the absence of long atmospheric residence times or long-range atmospheric transport processes. Characteristic tracer ratios of road traffic emissions were identified: Cu/Sb = 6.8–8.0, Cu/Sn = 4.7–5.4 and Sn/Sb = 1.5.
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Al-Mosawi, Fatima Husham, Dunya A. Al-Abbawy und Abbas F. Abbas. „Synthesis, Analytical and Uptake Behavior of Copper, Cadmium and Lead by New Schiff-base Chelating resin“. Research Journal of Chemistry and Environment 26, Nr. 12 (25.11.2022): 106–12. http://dx.doi.org/10.25303/2612rjce1060112.
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The current study aims to improve the quality of wastewater collected from the raw, primary sedimentation tank and secondary sedimentation tank of Hamdan wastewater treatment plant, Basrah, Iraq. Heavy metals contamination is one of the most critical environmental issues. Therefore, appropriate steps need to reduce pollutants in wastewater to acceptable levels before being discharged to the environment. Several treatment methods have been developed recently to adsorb these pollutants. This study reviews the ability of polymer, a new resin (3,3'-(1,4- phenylene) bis(1-(4-(4-hydroxybenzylidene) amino) phenyl) prop-2-en-1-one) to adsorb copper, cadmium and lead from wastewater. The new Schiff base was prepared on polyurethane foam diagnosed by FT-IR and 1H-NMR spectroscopic methods. The polymer has excellent sorption capacities due to the large specific surface area, chemical composition and the removal metals efficiency in varying proportions. For Cd2+, the efficiency removal was 100% in wastewater and the efficiency of removing Cu2+ was 100% in raw wastewater and primary sedimentation tank. The removal efficiency of Pb2+ was 86%, 64% and 79% 79% in raw sewage, primary and secondary sedimentation tank respectively.
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Su, Zhihua, Xin Li, Yunlong Liu und Bing Deng. „The Multi-Time Scale Changes in Air Pollutant Concentrations and Its Mechanism before and during the COVID-19 Periods: A Case Study from Guiyang, Guizhou Province“. Atmosphere 12, Nr. 11 (11.11.2021): 1490. http://dx.doi.org/10.3390/atmos12111490.
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The lockdown during the coronavirus disease 2019 (COVID-19) pandemic provides a scarce opportunity to assess the efficiency of air pollution mitigation. Herein, the monitoring data of air pollutants were thoroughly analyzed together with meteorological parameters to explore the impact of human activity on the multi-time scale changes of air pollutant concentrations in Guiyang city, located in Southwest China. The results show that the COVID-19 lockdown had different effects on the criteria air pollutants, i.e., PM2.5 (diameter ≤ 2.5 μm), PM10 (diameter ≤ 10 μm), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) concentrations. The lockdown caused a significant drop in NO2 concentration. During the first-level lockdown period, the NO2 concentration declined sharply by 8.41 μg·m−3 (45.68%). The decrease in NO concentration caused the “titration effect” to weaken, leading to a sharp increase in O3 concentration. Although human activities resumed partially and the “titration effect” enhanced certainly during the second-level lockdown period, the meteorological conditions became more conducive to the formation of O3 by photochemical reactions. Atmosphere oxidation was enhanced to promote the generation of secondary aerosols through gas–particle transitions, thus compensating for the reduced primary emission of PM2.5. The implication of this study is that the appropriate air pollution control policies must be initiated to suppress the secondary generation of both PM2.5 and O3.
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Wang, Hao. „Influence of Hydraulic Loading Rate on Horizontal Zeolite Wetland Effluent Quality“. Advanced Materials Research 573-574 (Oktober 2012): 659–62. http://dx.doi.org/10.4028/www.scientific.net/amr.573-574.659.
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In Tangshan area, the secondary effluent of wastewater treatment plants was used for this study. Horizontal zeolite wetland was carried out treating it. Hydraulic loading rate was the parameters for analyzing the nitrogen and phosphorus removal efficiency of pollutants from the secondary effluent of wastewater treatment plant. Zeolite constructed wetlands showed different behaviors for nitrogen and phosphorus removals.Under the optimum hydraulic loading rate, the primary pollutions were removed to a large extent.
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Tafti, Mojtaba Dehqani, Faramarz Doulati Ardejani, Mohammad Fatehi Marji und Yousef Shiri. „Simulation of groundwater contamination by leakage from waste-filled mine“. Rudarsko-geološko-naftni zbornik 36, Nr. 5 (2021): 49–55. http://dx.doi.org/10.17794/rgn.2021.5.5.
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Mining wastes are a great source of pollutants. Open-pit backfill materials can be found as waste rock and as tailings. The aim of the current study was the investigation of the contaminant transportation pathways by groundwater flow from these waste materials through heterogeneous porous media. Numerical Lattice Boltzmann Method (LBM) was used for examining the effects of different factors on pollutant transportation through groundwater beneath the waste materials. Grain size, vertical and horizontal fracturing, and hydraulic pressure gradient were factors considered here. The results showed that contaminant transportation by the groundwater flow from the waste materials through porous media depends on primary and secondary matrix porosity of the open-pit material, heterogeneity in permeability of aquifer rock, and hydraulic head of groundwater.
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Obiebi, Irikefe Paul, und Patrick Gold Oyibo. „A cross-sectional analysis of respiratory ill-health among charcoal workers and its implications for strengthening occupational health services in southern Nigeria“. BMJ Open 9, Nr. 1 (Januar 2019): e022361. http://dx.doi.org/10.1136/bmjopen-2018-022361.
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ObjectivesThis study was conducted to assess the concentration of air pollutants at charcoal sites, the dose-response relationship between site-based exposure levels to air pollutants and prevalence of respiratory symptoms among charcoal workers, and the measures these workers employ to safeguard their health.DesignCross-sectional but comparative designSettingCharcoal production kiln sites in Sapele, Delta State, Nigeria.ParticipantsOverall 296 charcoal workers and age-matched, sex-matched and height-matched non-exposed traders (comparison group).Primary and secondary outcome measuresThe primary outcome measure was the prevalence of respiratory symptoms among charcoal workers while secondary outcomes included lung function indices as well as hazard control practices among charcoal workers.ResultsMajority (83.3%) of the sites had PM10and PM2.5values five times higher than the WHO standard. Charcoal workers were more likely to have respiratory symptoms; wheeze was statistically significant after adjusting for confounders, (OR 4.22; CI 1.37 to 12.99). The dose-response relationship between site-based exposure levels to air pollutants and the prevalence of respiratory symptoms among charcoal workers was statistically significant for all symptoms except chest tightness (p=0.167). Mean forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) were considerably lower among workers with differences of −0.22 (−0.42 to −0.05) L and −0.52 (-0.76 to −0.29) L, respectively, whereas FEV1/FVC ratio and peak expiratory flow rate were higher among workers with mean differences of 5.68 (3.59–8.82)% and 0.31 (-23.70 to 24.43) L/min, respectively; but the mean difference was significant only for the FEV1/FVC ratio. Charcoal workers had poor hazard control practices; only 3.4% reportedly used personal protective equipment.ConclusionAir pollutants at kiln sites were higher than WHO standards. Despite the significantly higher prevalence of wheeze, chest tightness and chronic cough among charcoal workers, their hazard control practices were inadequate. Charcoal workers should adopt appropriate hazard control practices, and use improved devices which emit minimal pollutants.
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Wu, Pei-Chih, Huey-Jen Su und David Kung. „Primary Products Emitted From Evaporating Essential Oils and Potential Secondary Pollutants From Their Reactions With Oxidants“. Epidemiology 22 (Januar 2011): S40. http://dx.doi.org/10.1097/01.ede.0000391783.44762.ad.
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Juodis, Laurynas, Vitold Filistovič, Evaldas Maceika und Vidmantas Remeikis. „Analytical dispersion model for the chain of primary and secondary air pollutants released from point source“. Atmospheric Environment 128 (März 2016): 216–26. http://dx.doi.org/10.1016/j.atmosenv.2015.12.019.
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Naresh, Ram, Shyam Sundar und J. B. Shukla. „Modeling the removal of primary and secondary pollutants from the atmosphere of a city by rain“. Applied Mathematics and Computation 179, Nr. 1 (August 2006): 282–95. http://dx.doi.org/10.1016/j.amc.2005.11.101.
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Lin, Chao, Yunyi Wang, Ryozo Ooka, Cédric Flageul, Youngseob Kim, Hideki Kikumoto, Zhizhao Wang und Karine Sartelet. „Modeling of street-scale pollutant dispersion by coupled simulation of chemical reaction, aerosol dynamics, and CFD“. Atmospheric Chemistry and Physics 23, Nr. 2 (26.01.2023): 1421–36. http://dx.doi.org/10.5194/acp-23-1421-2023.
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Abstract. In the urban environment, gas and particles impose adverse impacts on the health of pedestrians. The conventional computational fluid dynamics (CFD) methods that regard pollutants as passive scalars cannot reproduce the formation of secondary pollutants and lead to uncertain prediction. In this study, SSH-aerosol, a modular box model that simulates the evolution of gas, primary and secondary aerosols, is coupled with the CFD software, OpenFOAM and Code_Saturne. The transient dispersion of pollutants emitted from traffic in a street canyon is simulated using the unsteady Reynolds-averaged Navier–Stokes equations (RANS) model. The simulated concentrations of NO2, PM10, and black carbon (BC) are compared with field measurements on a street of Greater Paris. The simulated NO2 and PM10 concentrations based on the coupled model achieved better agreement with measurement data than the conventional CFD simulation. Meanwhile, the black carbon concentration is underestimated, probably partly because of the underestimation of non-exhaust emissions (tire and road wear). Aerosol dynamics lead to a large increase of ammonium nitrate and anthropogenic organic compounds from precursor gas emitted in the street canyon.
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Javed, Ammar, Farheen Aamir, Umar Farooq Gohar, Hamid Mukhtar, Muhammad Zia-UI-Haq, Modhi O. Alotaibi, May Nasser Bin-Jumah, Romina Alina Marc (Vlaic) und Oana Lelia Pop. „The Potential Impact of Smog Spell on Humans’ Health Amid COVID-19 Rages“. International Journal of Environmental Research and Public Health 18, Nr. 21 (29.10.2021): 11408. http://dx.doi.org/10.3390/ijerph182111408.
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Rapid and unchecked industrialization and the combustion of fossil fuels have engendered a state of fear in urban settlements. Smog is a visible form of air pollution that arises due to the over-emissions of some primary pollutants like volatile organic compounds (VOCs), hydrocarbons, SO2, NO, and NO2 which further react in the atmosphere and give rise to toxic and carcinogenic secondary smog components. Smog reduces the visibility on roads and results in road accidents and cancellation of flights. Uptake of primary and secondary pollutants of smog is responsible for several deleterious diseases of which respiratory disorders, cardiovascular dysfunction, neurological disorders, and cancer are discussed here. Children and pregnant women are more prone to the hazards of smog. The worsening menace of smog on one hand and occurrence of pandemic i.e., COVID-19 on the other may increase the mortality rate. But the implementation of lockdown during pandemics has favored the atmosphere in some ways, which will be highlighted in the article. On the whole, the focus of this article will be on the dubious relationship between smog and coronavirus.