Emissions Of Compounds Research Articles

Evaluation of additives used in gasoline vehicles in China: fuel economy, regulated gaseous pollutants and volatile organic compounds based on both chassis dynamometer and on-road tests

Using gasoline additives is one of the economical approaches to achieving higher engine efficiency and lower pollutant emissions. However, a limited understanding of the actual effects of various additives is one obstacle to replacing outdated additive standards. In this study, the effects of 14 popular additives from the Chinese market on fuel consumption and carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) emissions were evaluated based on the chassis dynamometer; then, one qualified additive was selected, and the on-road impacts on regulated gaseous and volatile organic compound (VOC) emissions were investigated using a portable emission measurement system. The results of the dynamometer tests showed that 9 of the 14 additives were beneficial in reducing CO emissions, with eight and seven beneficial for HC and NOx, respectively. Most of the test additives reduced the fuel consumption by 0.9–3.5%, while three additives had significant adverse effects. The on-road tests showed that the qualified additive could not only reduce on-road regulated gaseous emissions but also decrease most of VOC group, with decreases of 81.7% for aromatics, 79.4% for alkanes, 43.7% for halocarbons and 66.3% for alkenes. The vehicle-specific power (VSP) analysis showed that the test additive reductions in CO and HC emissions primarily occurred on highway roads because of the smoother vehicle operation. The results of this study indicated that quite a few additives might deteriorate the fuel consumption and tailpipe emissions, so the standards should be updated and market supervision should be further strengthened.

Chemical compounds released by combustion of polymer composites flat belts

Machines and devices for the production, transport and segregation of products are placed in production and storage rooms. Flat conveyor and drive belts are very often used for their construction. Due to heavy loads and difficult operating conditions, these belts can catch fire and, as a result, become the main source of air contaminants harmful to human health and life. This article examines the emission level of toxic chemical compounds most often produced during the thermal decomposition and combustion of flat drive and conveyor belts. Six types of flat belts, which were made of various polymer materials, i.e., polyamide, rubber, and polyurethane, and were pyrolyzed in a tube furnace at 950 °C, were tested for emission. Using an Fourier transform infrared spectroscopy gas analyser, five gaseous products of combustion were identified, i.e., carbon mono oxide, carbon dioxide, hydrogen cyanide, hydrogen bromide and sulfur dioxide (SO2). Chemical analysis showed that SO2 compounds and hydrogen bromide were present in only two samples. The test results indicate that gas emission concentration limits for all the tested belts were significantly exceeded. A comparative analysis of the concentration limits of V-belts described in the authors' earlier works shows that flat belts demonstrate lower emission levels of harmful compounds than V-belts. In addition, research has shown that compared to traditional rubber-based belts, belts made of modern materials exhibit no emission of hydrogen chloride compounds during thermal decomposition and combustion.

Influence of polymer additives on gas-phase emissions from 3D printer filaments

A collection of six commercially available, 3D printer filaments were analyzed with respect to their gas-phase emissions, specifically volatile organic compounds (VOCs), during simulated fused filament fabrication (FFF). Filaments were chosen because they were advertised to contain metal particles or carbon nanotubes. During experimentation, some were found to contain other non-advertised additives that greatly influenced gas-phase emissions. Three polylactic acid (PLA) filaments containing either copper, bronze, or stainless steel particles were studied along in addition to three carbon nanotube (CNT) filaments made from PLA, acrylonitrile-butadiene-styrene (ABS), and polycarbonate (PC). The metal-additive PLA filaments were found to emit primarily lactide, acetaldehyde, and 1-chlorododecane. The presence of metal particles in the PLA is a possible cause of the increased total emissions, which were higher than any other PLA filament reported in the literature. In addition, the filament with stainless steel particles had a threefold increase in total VOCs compared to the copper and bronze particles. Two of three CNT-containing filaments emitted compounds that have not been reported before for PLA and PC. A comparison between certain emitted VOCs and their suggested maximum inhalation limits shows that printing as little as 20 g of certain filaments in a small, unventilated room can subject the user to hazardous concentrations of multiple toxic VOCs with carcinogenic properties (e.g., acetaldehyde, 1,4-dioxane, and bis(2-ethylhexyl) phthalate). The use of certain additives, whether advertised or not, should be reevaluated due to their effects on VOC emissions during 3D printing.

Infection of susceptible/tolerant barley genotypes with Barley yellow dwarf virus alters the host plant preference of Rhopalosiphum padi clones depending upon their ability to transmit BYDV

Discovering mechanisms of plant–virus–vector interactions is fundamental to understand their ecology and evolution and to apply this knowledge in plant protection. To study the influence of varying Barley yellow dwarf virus (BYDV) transmission efficiencies on host plant preference of Rhopalosiphum padi (L.) clones, we performed host choice experiments with two barley cultivars (BYDV susceptible cv. ‘Rubina’ and BYDV tolerant cv. ‘Vixen’) including healthy and virus-infected plants. For the susceptible barley cultivar ‘Rubina’, aphid clone R07 (high transmission efficiency) preferred BYDV-infected over healthy host plants after 24 h, while clones D10 (medium transmission efficiency) and R09 (low transmission efficiency) preferred neither host. In contrast, BYDV infection of ‘Vixen’ did not affect the plant’s appeal for aphid clone R07. Host plant access, indicated by ingestion and observed by electrical penetration graph technique for a period of 2 h, was facilitated on BYDV-infected cv. ‘Rubina’ for the clones R07 and D10, whereas an opposite effect was observed for the clone R09. For R07 and R09, the difference was not visible after a period of 5 h. As observed earlier for BYDV-infected wheat, enhanced emission of volatile organic compounds associated with virus-induced attraction was detected for BYDV-infected cv. ‘Rubina.’ It is concluded that host plant preference is possibly linked with a high BYDV transmission efficiency as observed for the clone R07, leading to a fitness advantage of this clone as indicated by early increased ingestion. This advantage is not present on BYDV-tolerant genotypes most likely due to the absence of infection symptoms.

Heatwave frequency and seedling death alter stress-specific emissions of volatile organic compounds in Aleppo pine

Biogenic volatile organic compounds (BVOC) play important roles in plant stress responses and can serve as stress indicators. While the impacts of gradual environmental changes on BVOCs have been studied extensively, insights in emission responses to repeated stress and recovery are widely absent. Therefore, we studied the dynamics of shoot gas exchange and BVOC emissions in Pinus halepensis seedlings during an induced moderate drought, two four-day-long heatwaves, and the combination of drought and heatwaves. We found clear stress-specific responses of BVOC emissions. Reductions in acetone emissions with declining soil water content and transpiration stood out as a clear drought indicator. All other measured BVOC emissions responded exponentially to rising temperatures during heat stress (maximum of 43 °C), but monoterpenes and methyl salicylate showed a reduced temperature sensitivity during the second heatwave. We found that these decreases in monoterpene emissions between heatwaves were not reflected by similar declines in their internal storage pools. Because stress intensity was extremely severe, most of the seedlings in the heat-drought treatment died at the end of the second heatwave (dark respiration ceased). Interestingly, BVOC emissions (methanol, monoterpenes, methyl salicylate, and acetaldehyde) differed between dying and surviving seedlings, already well before indications of a reduced vitality became visible in gas exchange dynamics. In summary, we could clearly show that the dynamics of BVOC emissions are sensitive to stress type, stress frequency, and stress severity. Moreover, we found indications that stress-induced seedling mortality was preceded by altered methanol, monoterpene, and acetaldehyde emission dynamics.

ASSESSMENT OF DIRECT PYROGENIC CARBON EMISSIONS IN RUSSIAN FORESTS FOR 2020 USING REMOTE MONITORING DATA

The paper presents the results of assessing pyrogenic emissions of carbon compounds in Russian forests for 2020 using remote monitoring methods. The area of forests damaged by fires was 6.5 mln ha, whereas the amount of carbon emissions was 36.5 MtC. Although the total area of damage is higher than the average annual values, the amount of pyrogenic carbon emissions is lower than the average annual ones. In absolute terms, the year corresponds to 2016. We registered an increase in annual carbon emissions from fires since the abnormal 2012. A preliminary analysis of the entire observation period for fires suggests that 2021 may be the next abnormal year after the years of 2003 and 2012 in terms of forest fires and direct pyrogenic carbon emissions into the atmosphere.

Influence of biomass burning vapor wall loss correction on modeling organic aerosols in Europe by CAMx v6.50

Abstract. Increasing evidence from experimental studies suggests that the losses of semi-volatile vapors to chamber walls could be responsible for the underestimation of organic aerosol (OA) in air quality models that use parameters obtained from chamber experiments. In this study, a box model with a volatility basis set (VBS) scheme was developed, and the secondary organic aerosol (SOA) yields with vapor wall loss correction were optimized by a genetic algorithm based on advanced chamber experimental data for biomass burning. The vapor wall loss correction increases the SOA yields by a factor of 1.9–4.9 and leads to better agreement with measured OA for 14 chamber experiments under different temperatures and emission loads. To investigate the influence of vapor wall loss correction on regional OA simulations, the optimized parameterizations (SOA yields, emissions of intermediate-volatility organic compounds from biomass burning, and enthalpy of vaporization) were implemented in the regional air quality model CAMx (Comprehensive Air Quality Model with extensions). The model results from the VBS schemes with standard (VBS_BASE) and vapor-wall-loss-corrected parameters (VBS_WLS), as well as the traditional two-product approach, were compared and evaluated by OA measurements from five Aerodyne aerosol chemical speciation monitor (ACSM) or aerosol mass spectrometer (AMS) stations in the winter of 2011. An additional reference scenario, VBS_noWLS, was also developed using the same parameterization as VBS_WLS except for the SOA yields, which were optimized by assuming there is no vapor wall loss. The VBS_WLS generally shows the best performance for predicting OA among all OA schemes and reduces the mean fractional bias from −72.9 % (VBS_BASE) to −1.6 % for the winter OA. In Europe, the VBS_WLS produces the highest domain average OA in winter (2.3 µg m−3), which is 106.6 % and 26.2 % higher than VBS_BASE and VBS_noWLS, respectively. Compared to VBS_noWLS, VBS_WLS leads to an increase in SOA by up to ∼80 % (in the Balkans). VBS_WLS also leads to better agreement between the modeled SOA fraction in OA (fSOA) and the estimated values in the literature. The substantial influence of vapor wall loss correction on modeled OA in Europe highlights the importance of further improvements in parameterizations based on laboratory studies for a wider range of chamber conditions and field observations with higher spatial and temporal coverage.

Emissions of biogenic volatile organic compounds (BVOCs) from the rhizosphere of Scots pine (Pinus sylvestris) seedlings exposed to warming, moderate N addition and bark herbivory by large pine weevil (Hylobius abietis)

AimsBiogenic volatile organic compound (BVOC) research has been mostly focused on foliar emissions. In this experiment, the main focus was on rhizosphere BVOC emissions of Scots pine seedlings under changing growth conditions.MethodsSoil-growing Scots pines were exposed to increased air (0.5°C) and soil (4.0°C) temperature and N addition (30 kg N ha− 1 yr− 1) for three growing seasons in a field experiment. In addition to these factors, seedlings were exposed to bark herbivory by large pine weevils in two last seasons. Gas-chromatography and mass-spectrometry was used for analyzing the BVOC samples collected from pine rhizosphere.ResultsAlmost 98 % of BVOCs were non-oxygenated monoterpenes (nMTs), 1 % oxygenated monoterpenes (oMTs), 0.5 % sesquiterpenes (SQTs), and 1 % other BVOCs. In both years, there was an interaction of warming, N addition and bark herbivory on rhizosphere BVOC emissions. In 2015, warming and N addition in single exposures decreased oMT emissions, while herbivory in single exposure increased oMT emissions. In 2016, the three-way interaction showed that the effects of warming, N addition and herbivory on BVOCs were mainly detected in single exposures. In 2016, warming decreased nMT, oMT, SQT and other BVOC emissions; N addition decreased oMT and SQT emissions; and herbivory decreased SQT and other BVOC emissions.ConclusionsWarming and N addition in single exposures decreased the rhizosphere BVOC emissions. The effect of bark herbivory on BVOC emissions varied between the years from increase to decrease. It seems that under altered growth conditions Scots pine seedlings may reduce carbon investment to rhizosphere BVOCs.

Synthesis and properties of star-shaped polyesters for high-solid-content two-component polyurethane wood coatings

As the laws about emission of volatile organic compounds (VOCs) become more and more stringent, low VOC content coatings, such as high solid polyurethane coating, gradually attract great attention. Herein, a series of star-shaped hydroxyl polyesters (SHPs) were synthesized by methyl hexahydrophthalic anhydride (MHHPA), diisopropanolamine (DIPA), and monoglycidyl ether. The number of their average molecular weights is ranged from 913 to 1390 with 1.55–1.75 of PDI. The viscosities of SHPs are low to 1060 mPa·s. The molecular structures of SHPs were characterized by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectroscopies. The high-solid two-component polyurethane coatings (2 K-PU) from SHP-3 have a 65% of the solid contents and exhibit 20 mPa·s of the applied viscosity with 310 g/L of VOC contents. Moreover, the polyurethane film displays high coating hardness up to 2H, as well as excellent chemical resistance and good thermal stability.

Objective odor analysis of incidentally emitted compounds using the Langage des Nez® method: application to the industrial zone of Le Havre.

Environmental odor studies are usually done using two approaches: nuisance impact assessment and source identification. The latter may be done using chemical analysis or sensory analysis. While sensory analyses offer many advantages, they also face the main obstacle: odor nature description still uses conventional methods based on subjective evocations as odor descriptors. This makes the sensory method ineffective especially when the expected outcome is the source identification in the context of an industrial accident. This work wants to fulfill this gap proposing to build an objective database including the odor nature description of selected potentially emitted compounds using a promising approach: the Langage des Nez® (LdN). Using definite odorous compounds as odor referents, this work provides the odor nature description of 44 compounds, reported as potential incidentally released chemical compounds in the industrial zone of Le Havre. The city of Le Havre, France, was chosen as a model due to a history of odorous emissions of industrial origins. A trained panel described the odor of each compound using up to three referents of the LdN referents collection and attributed a score to each referent. A data analysis method was developed based on the frequency of citation of the referents and the attributed scores allowing the categorization of each compound in three types of consensus categories. The data analysis results showed that around 80% of compounds were described with a good consensus, showing the LdN as a well-adapted lexicon. This study does not point to any correlation between the chemical structures of the compounds of interest and their relative referents. When compared to conventional methods, LdN revealed a more objective and precise approach. The proposed experimental method and the results provided in this work offer the first insight for time-efficient approaches to objectively describe environmental odors, especially potentially emitted odors during incidents. This work may be supplemented by abatement and mixture effect investigations for a complete understanding of odor dispersion.

Estudio de estrategias verdes como medida para mitigar la contaminación marina generada por buques.

Due to the constant growth in import and export operations, it has equally increased global maritime trade, especially for its safety, efficiency and economy compared with other modes of transport. However, shipping has been one of the causes of the negative impact that affects the environment due to pollution generated by ships that produces deterioration in the ozone by emissions of organic gaseous compounds that promote extinction of the species and marine habitat due to spills of toxic liquids, ballast water, containers that falls into the sea, among other polluting sources. For the above, We found a reason to made a qualitative study based on statistics, information from agencies responsible for regulating the sector, international projects for the prevention of marine pollution by ships, scientific journal articles and existing studies on the amount of marine pollution and through this information, identify strategies that promote the development and implementation of green logistics in the mention sector in order to mitigate pollution it generates.

Comparing Permitted Emissions to Atmospheric Observations of Hydrocarbons in the Eagle Ford Shale Suggests Permit Violations

The recent decade’s rapid unconventional oil and gas development in the Eagle Ford of south-central Texas has caused increased hydrocarbon emissions, which we have previously analyzed using data from a Texas Commission on Environmental Quality air quality monitoring station located downwind of the shale area. Here, we expand our previous top-down emissions estimate and compare it to an estimated regional emissions maximum based on (i) individual facility permits for volatile organic compound (VOC) emissions, (ii) reported point source emissions of VOCs, (iii) traffic-related emissions, and (iv) upset emissions. This largely permit-based emissions estimate accounted, on average, for 86% of the median calculated emissions of C3-C6-hydrocarbons at the monitor. Since the measurement-based emissions encompass a smaller section of the shale than the calculated maximum permitted emissions, this strongly suggests that the actual emissions from oil and gas operations in this part of the Eagle Ford exceeded their permitted allowance. Possible explanations for the discrepancy include emissions from abandoned wells and high volumes of venting versus flaring. Using other recent observations, such as large fractions of unlit flares in the Permian shale basin, we suggest that the excessive venting of raw gas is a likely explanation. States such as Texas with significant oil gas production will need to require better accounting of emissions if they are to move towards a more sustainable energy economy.

The Air and Sewage Pollutants from Biological Waste Treatment

The mechanical-biological waste treatment plants (MBTP), which include the municipal waste biogas plants, have an important role in sustainable urban development. Some plants are equipped with a sewage pre-treatment plant, which is then directed to the sewerage system and the treatment plant. Others, on the other hand, have only a non-drainage tank. The parameters of technological sewage (TS) or processing technology could reduce sewage contamination rates. In addition to the quality of sewage from waste treatment plants, the emission of odours is also an important problem, as evidenced by the results obtained over the sewage pumping station tank. The conducted statistical analysis shows a significant positive correlation between odour concentration (cod) and volatile organic compounds (VOCs). Analysing the individual compounds, a high positive correlation was also found—the strongest being between H2S, NH3 and VOCs. In the case of sewage compounds, the insignificant correlation between P total and other parameters was found. For the rest of the compounds, the highest positive correlation was found between COD and BOD and N-NO2 and N-NH3 as well as COD and N-NO2. The dilution of sewage is only an ad hoc solution to the problem. Further work should be aimed at reducing sewage pollution rates. The obtained results indicate large pollution of technological sewage and a high level of odour and odorants concentration. The novelty and scientific contribution presented in the paper are related to analyses of various factors on technological sewage parameters and odour and odorant emission from TS tank at biogas plant processing municipal waste, which may be an important source of knowledge on the management of TS, its disposal and minimisation of emitted compound emissions.

Оценка влияния сжигания попутного газа на радиальный прирост Pinus sylvestris (Озёрное месторождение нефти, Пермский край, Россия)

The paper discusses the question of influence of associated gas flaring on radial growth of Pinus sylvestris. The studied area is Ozernoye oil field of Krasnovishersky district of Perm region (Russia). The main research method is dendrochronological analysis. The wood cores of Pinus sylvestris were selected in the summer of 2020 using a Pressler increment borer according to the standard methodology. Cores were taken from two plots. The main plot is 100 m from the associated gas flaring torch and background plot is 11 km from the torch. The calculation and measurement of the width of the radial growth of wood were made on the machine for measuring tree rings – LINTAB 6. Numerical parameters of wood growth obtained for both plots. The average value growth of wood at the main plot is 1.426 mm/year; at the background plot – 1.808 mm/year. The relative decrease of average growth of wood over 20 years before and after the start of associated gas flaring at the main plot 1.45 times higher than at the background plot. The radial growth decreases systematically at both plots for 20 years since the beginning of associated gas flaring. But the rates of decrease are 1.52–1.67 times higher near the torch. The trend for recovery, as well as increase in the growth values, 10-20 years after the start of associated gas flaring, was not revealed. Therefore, the explicit negative impact of associated gas combustion on the radial growth of wood in nearest forest were noted. Maximum growth rates at the main plot were noted for trees ages 0-55 years. It is not supporting the conclusions of some researches [7,37] that Pinus sylvestris has the most intense growth during 30-35 years old. Revealed [37] high levels of chemical and dust atmospheric contamination, reducing growth of wood, most likely cannot be achieved by the associated gas flaring by the single torch. Positive (fertilizing) influence of Ca, K, Na, Mg, Mn [29,30] compounds emissions is not marked as well. We guess that thermal – is the main negative factor for the plot near associated gas flaring. Our research could be continued to the studying of the influence of spatial, climatic aspects, volume and intensity of gas flaring process on the state of forest stand.

Mathematical Model of VOCs Emission in Three-layer Building Materials

A simple mathematical model is proposed to account for emissions of Volatile Organic Compounds (VOCs) from three-layer building materials. The model considers both the diffusion within three layer building materials and the mass transfer resistance through the air boundary layer. A general solution method based on Laplace transform is presented. Compared to other models capable of accounting for emissions of VOCs from multi layer building materials, the present model is fully analytical instead of being numerical. The present model was validated by the experimental data from the specially designed test. The results indicated that there was a good agreement between the model predictions and the experimental data. It can also be seen from calculation that model ignoring the boundary layer resistance cannot fully reflect the real situation.

Cu(I)-I-2,4-diaminopyrimidine Coordination Polymers with Optoelectronic Properties as a Proof of Concept for Solar Cells.

Two coordination polymers with formulas [CuI(dapym)]n and [Cu2I2(dapym)]n (dapym = 2,4-diaminopyrimidine) have been synthesized in water at room temperature. According to the stoichiometry used, mono (1D) and the two-dimensional (2D) structures can be obtained. Both are made up of Cu2I2 double chains. Their high insolubility in the reaction medium also makes it possible to obtain them on a nanometric scale. Their structural flexibility and short Cu-Cu distances provoke interesting optoelectronic properties and respond to physical stimuli such as pressure and temperature, making them interesting for sensor applications. The experimental and theoretical studies allow us to propose different emission mechanisms with different behaviors despite containing the same organic ligand. These behaviors are attributed to their structural differences. The emission spectra versus pressure and temperature suggest competencies between different transitions, founding critical Cu2I2 environments, i.e., symmetric in the 1D compound and asymmetric for the 2D one. The intensity in the 2D compound's emission increases with decreasing temperature, and this behavior can be rationalized with a structural constriction that decreases the Cu-Cu and Cu-I distances. However, compound 1D exhibits a contrary behavior that may be related to a change of the organic ligand's molecular configuration. These changes imply that a more significant Π-Π interaction counteracts the contraction in distances and angles when the temperature decreased. Also, the experimental conductivity measurements and theoretical calculations show a semiconductor behavior. The absorption of the 1D compound in UV, its intense emission at room temperature, and the reduction to nanometric size have allowed us to combine it homogeneously with ethyl vinyl acetate (EVA), creating a new composite material. The external quantum efficiency of this material in a Si photovoltaic mini-module has shown that this compound is an active species with application in solar cells since it can move the photons of the incident radiation (UV region) to longer wavelengths.

Perfection of equipment and technology of steel ladles lining drying and heating to neutralize emissions of organic binders decomposition products

Technological operations of steel ladles lining drying and heating are accompanied by formation and emission of compounds, referred to the first and second category of danger. This is attributed mainly to the presence in the refractory’s composition phenol-formaldehyde tars and coal pitch as binders. Results of simulation of steel ladle lining heating operation presented. The filtration speed distribution of decomposition products in the lining material established. The main part of harmful substances from the lining is emitted in the process of its drying into internal working space of the ladle. Less than 10% of the total amount of pollution substances goes out through the external evaporating openings in the ladle armor. It was shown, that within near 90% of drying and heating time, the temperature in the ladle does not exceed level of 800 °С, which is not enough for harmful substances afterburning. Reasonability of afterburning of the formed harmful emissions justified as a separate technological element of the facility of ladles drying. For the afterburning, not expensive materials should be used, having catalyst properties and developed surface. Application of catalyst enables to decrease the minimum necessary temperature for oxidation of decomposition products down to 600-650 °С. Description of the facility, developed by Concern “Jet Technologies”, for ladles drying and heating with neutralization exhausted technological gases presented. The facility has an airtight shelter, in which a ladle with new lining is placed. The shelter has a lifting cover, in which a gas-air burner is installed. The burner can operate with a high excess of air to provide minimal temperature of drying agent at early stages of drying. Inside the shelter a negative pressure is kept for active removal technological gases and prevention of penetrating them into the working zone of the shop. The power of the burner is controlled by the temperature, measured by a thermo-converter in the cover. Out of the shelter the technological gases are directed to a thermocatalyst reactor (TCR). The TCR has another burner for additional heating of gases leaving the ladle, to the afterburning temperature. Power control is made also based on the measured temperature. After completion of emitting binder decomposition products, the TCR is switched off. After neutralization in the TCR, the technological gases are emitted into atmosphere through a smoke stack. The facility operation control is made by a local control system, based on an industrial logic controller. At the EAF-based plant “NLMK-Kaluga”, the ladles with phenol-based binder lining are successfully dried for many years already at a facility described in the paper, providing an ecological safety of the emissions.

ASSESSMENT OF AIR POLLUTION IN THE CITIES OF PERM REGION

The chemicals emitted from stationary and mobile sources into the air in cities have a harmful effect on the population, contributing to the growth of morbidity and mortality and disturbing the natural environment. In Perm Krai, Russia, industrial facilities discharge about 360 chemicals into the air. The airborne pollution mostly comes from chemical industry, oil and minerals extraction, metallurgical industry, power generation, and transport. This study focused on the assessment of airborne pollution in the cities of Perm Krai. The study used data of the Perm Center for Hydrometeorology and Environmental Monitoring, published in annual environmental reports. It was found that the main pollutant emissions from stationary sources are liquid and gaseous substances. The most common emission components are hydrocarbons coming from pipeline transportation facilities. The second most common substance is carbon monoxide emitted by combustion of various fuels. Gross pollutant emissions tended to increase from 2014 to 2018, with a steady growth of emissions from mobile sources. Airborne pollution was assessed by the comprehensive air quality index, taking into account several substances that make the largest contribution to airborne pollution (this year). The monitoring results from Berezniki, Gubakha, Krasnokamsk, Lysva, Perm, Solikamsk and Tchaikovsky were analyzed. The paper presents the dynamics of air quality index in these cities from 2008 to 2018. The highest index value (‘very high’) was observed in Solikamsk in 2012; the lowest index value, in Tchaikovsky. The airborne pollution in these cities showed a tendency to decrease over the past six years, possibly, due to the use of more advanced emissions cleaning technologies and the decommissioning of some industrial facilities. The cities that have large industrial companies, such as Perm, Berezniki, Lysva and Solikamsk, experience the greatest environmental burden from stationary sources. Emissions of volatile organic compounds and sulfur dioxide from stationary sources increased from 2016 to 2018, although neither ‘high’, nor ‘very high’ pollution was observed in the cities of Perm Krai from 2013 to 2018.

Comparison of formaldehyde tropospheric columns in Australia and New Zealand using MAX-DOAS, FTIR and TROPOMI

Abstract. South-eastern Australia has been identified by modelling studies as a hotspot of biogenic volatile organic compound (VOC) emissions; however, long-term observational VOC studies are lacking in this region. Here, 2.5 years of multi-axis differential optical absorption spectroscopy (MAX-DOAS) formaldehyde (HCHO) measurements in Australasia are presented, from Broadmeadows, in northern Melbourne, Australia, and from Lauder, a rural site in the South Island of New Zealand. Across the measurement period from December 2016 to November 2019, the mean formaldehyde columns measured by the MAX-DOAS were 2.50±0.61×1015 molec. cm−2 at Lauder and 5.40±1.59×1015 molec. cm−2 at Broadmeadows. In both locations, the seasonal cycle showed a pronounced peak in Austral summer (December–January–February) consistent with temperature-dependent formaldehyde production from biogenic precursor gases. The amplitude of the seasonal cycle was 0.7×1015 molec. cm−2 at Lauder, and it was 2.0×1015 molec. cm−2 at Broadmeadows. The Lauder MAX-DOAS HCHO measurements are compared with 27 months of co-located Fourier transform infrared (FTIR) observations. The seasonal variation of Lauder MAX-DOAS HCHO, smoothed by the FTIR averaging kernels, showed good agreement with the FTIR measurements, with a linear regression slope of 1.03 and an R2 of 0.66 for monthly averaged formaldehyde partial columns (0–4 km). In addition to ground-based observations, a clear way to address the VOC measurement gap in areas such as Australasia is with satellite measurements. Here, we demonstrate that the TROPOspheric Monitoring Instrument (TROPOMI) can be used to distinguish formaldehyde hotspots in forested and agricultural regions of south-eastern Australia. The MAX-DOAS measurements are also compared to TROPOMI HCHO vertical columns at Lauder and Melbourne; very strong monthly average agreement is found for Melbourne (regression slope of 0.61 and R2 of 0.95) and a strong agreement is found at Lauder (regression slope of 0.73 and R2 of 0.61) for MAX-DOAS vs. TROPOMI between May 2018 and November 2019. This study, the first long-term satellite comparison study using MAX-DOAS in the Southern Hemisphere, highlights the improvement offered by TROPOMI's high resolution over previous satellite products and provides the groundwork for future studies using ground-based and satellite DOAS for studying VOCs in Australasia.

Wet Inorganic Nitrogen Deposition at the Daheitin Reservoir in North China: Temporal Variation, Sources, and Biomass Burning Influences

Atmospheric nitrogen deposition is of great concern to both air quality and the ecosystem, particularly in northern China, which covers one-quarter of China’s cultivated land and has many heavily air polluted cities. To understand the characteristics of wet N deposition at rural sites in northern China, one-year wet deposition samples were collected in the Daheitin reservoir region. Due to the intense emissions of gaseous nitrogen compounds from heating activities during cold seasons and distinct dilution effects under different rainfall intensities and frequencies, the volume weighted mean concentrations of wet N deposition showed higher levels in dry seasons but lower levels in wet seasons. In contrast, the wet N deposition rates varied consistently with precipitation, i.e., high during the wet season and lower during the dry season. The annual wet deposition rate of total inorganic ions (the sum of NO3−–N and NH4+–N) at the rural site in North China from July 2019 to June 2020 was observed at 18.9 kg N ha−1 yr−1, still remained at a relatively high level. In addition, biomass burning activities are ubiquitous in China, especially in northern China; however, studies on its impact on wet N deposition are limited. Non-sea salt potassium ion (nss-K+) was employed as a molecular tracer to investigate the characteristics of biomass burning activities as well as their impact on the chemical properties of wet N deposition. Three precipitation events with high nss-K+ levels were captured during the harvest season (June to July). The variations in the patterns of nss-K+, deposited N species, and ratios of nss-K+ to nitrogen species as well as their relationships all indicated that biomass burning emissions contributed remarkably to NO3−–N but had a minor influence on NH4+–N.