scholarly journals Use of high-volume outdoor smog chamber photo-reactors for studying physical and chemical atmospheric aerosol formation and composition

Author(s):  
E Borrás ◽  
M Ródenas ◽  
T Vera ◽  
A Muñoz
2021 ◽  
Vol 13 (14) ◽  
pp. 8031
Author(s):  
Syakirah Afiza Mohammed ◽  
Suhana Koting ◽  
Herda Yati Binti Katman ◽  
Ali Mohammed Babalghaith ◽  
Muhamad Fazly Abdul Patah ◽  
...  

One effective method to minimize the increasing cost in the construction industry is by using coal bottom ash waste as a substitute material. The high volume of coal bottom ash waste generated each year and the improper disposal methods have raised a grave pollution concern because of the harmful impact of the waste on the environment and human health. Recycling coal bottom ash is an effective way to reduce the problems associated with its disposal. This paper reviews the current physical and chemical and utilization of coal bottom ash as a substitute material in the construction industry. The main objective of this review is to highlight the potential of recycling bottom ash in the field of civil construction. This review encourages and promotes effective recycling of coal bottom ash and identifies the vast range of coal bottom ash applications in the construction industry.


2007 ◽  
Vol 7 (3) ◽  
pp. 8361-8393 ◽  
Author(s):  
L. E. Olcese ◽  
J. E. Penner ◽  
S. Sillman

Abstract. A new mechanism to simulate the formation of secondary organic aerosols (SOA) from reactive primary hydrocarbons is presented, together with comparisons with experimental smog chamber results and ambient measurements found in the literature. The SOA formation mechanism is based on an approach using calculated vapor pressures and a selection of species that can partition to the aerosol phase from a gas phase photochemical mechanism. The mechanism has been validated against smog chamber measurements using α-pinene, xylene and toluene as SOA precursors, and has an average error of 17%. Qualitative comparisons with smog chamber measurements using isoprene were also performed. A comparison against SOA production in the TORCH 2003 experiment (atmospheric measurements) had an average error of only 12%. This contrasts with previous efforts, in which it was necessary to increase partition coefficients by a factor of 500 in order to match the observed values. Calculations for rural and urban-influenced regions in the eastern U.S. suggest that most of the SOA is biogenic in origin, mainly originated from isoprene. A 0-dimensional calculation based on the New England Air Quality Study also showed good agreement with measured SOA, with about 40% of the total SOA from anthropogenic precursors. This mechanism can be implemented in a general circulation model (GCM) to estimate global SOA formation under ambient NOx and HOx levels.


2005 ◽  
Vol 5 (5) ◽  
pp. 8507-8646 ◽  
Author(s):  
G. McFiggans ◽  
P. Artaxo ◽  
U. Baltensperger ◽  
H. Coe ◽  
M. C. Facchini ◽  
...  

Abstract. The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the "indirect effects" are credited with the greatest range of uncertainty amongst the known causes of radiative forcing. This manuscript explores the effects that the composition and properties of atmospheric aerosol can have on the activation of droplets in warm clouds, so potentially influencing the magnitude of the indirect effect. The effects of size, composition, mixing state and various derived properties are assessed and a range of these properties provided by atmospheric measurements in a variety of locations is briefly reviewed. The suitability of a range of process-level descriptions to capture these aerosol effects is investigated by assessment of their sensitivities to uncertainties in aerosol properties and by their performance in closure studies. The treatment of these effects within global models is reviewed and suggestions for future investigations are made.


2010 ◽  
Vol 10 (6) ◽  
pp. 16055-16109 ◽  
Author(s):  
R. Chirico ◽  
P. F. DeCarlo ◽  
M. F. Heringa ◽  
T. Tritscher ◽  
R. Richter ◽  
...  

Abstract. Diesel particulate matter (DPM) is a significant source of aerosol in urban areas and has been linked to adverse health effects. Although newer European directives have introduced increasingly stringent standards for primary PM emissions, gaseous organics emitted from diesel cars can still lead to large amounts of secondary organic aerosol (SOA) in the atmosphere. Here we present results from smog chamber investigations characterizing the primary organic aerosol (POA) and the corresponding SOA formation at atmospherically relevant concentrations for three in-use diesel vehicles with different exhaust aftertreatment systems. One vehicle lacked exhaust aftertreatment devices, one vehicle was equipped with a diesel oxidation catalyst (DOC) and the final vehicle used both a DOC and diesel particulate filter (DPF). The experiments presented here were obtained from the vehicles at conditions representative of idle mode, and for one car in addition at a speed of 60 km/h. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used to measure the organic aerosol (OA) concentration and to obtain information on the chemical composition. For the conditions explored in this paper, primary aerosols from vehicles without a particulate filter consisted mainly of black carbon (BC) with a low fraction of organic matter (OM, OM/BC<0.5), while the subsequent aging by photooxidation resulted in a consistent production of SOA only for the vehicles without a DOC and with a deactivated DOC. After 5 h of aging ~80% of the total organic aerosol was on average secondary and the estimated "emission factor" for SOA was 0.23–0.56 g/kg fuel burned. In presence of both a DOC and a DPF, primary particles with a mobility diameter above 5 nm were 300±19 cm−3, and only 0.01 g SOA per kg fuel burned was produced within 5 h after lights on. The mass spectra indicate that POA was mostly a non-oxidized OA with an oxygen to carbon atomic ratio (O/C) ranging from 0.097 to 0.190. Five hours of oxidation led to a more oxidized OA with an O/C range of 0.208 to 0.369.


2021 ◽  
Author(s):  
Urmas Hõrrak ◽  
Xuemeng Chen ◽  
Kristo Hõrrak ◽  
Uko Rand ◽  
Kaupo Komsaare ◽  
...  

&lt;p&gt;The SMEAR Estonia station (58.277663 N, 27.308266 E, 36 m a.s.l.) was established in south-east of Estonia at the J&amp;#228;rvselja Experimental Forestry in 2012 to investigate the atmosphere-biosphere interactions and atmospheric aerosol formation and growth.&lt;/p&gt;&lt;p&gt;In summer 2019, the gamma-radiation monitor GammaTRACER XL2-3 (Saphymo GmbH) was set up at J&amp;#228;rvselja station and the rain sensor DRD11A (Vaisala Oyj) in autumn 2019. These devices enable to measure the gamma-radiation dose rate and precipitation intensity, which affect the ionization rate of atmospheric air close to ground, with high accuracy and time resolution, and complement our measurement system of atmospheric ions and aerosol particles.&lt;/p&gt;&lt;p&gt;The gamma-radiation dose rate measurements at about 1.2 m above the ground reveled on relatively steady background about 70 nSv/h occasional events with increase up to about 110 nSv/h, which correlated well with rainfall intensity. Commonly such events last 3-4 hours, but in specific meteorological situation with continuous long-lasting rain and air mass movement from southerly directions the effect can last 2-3 days, resulting in gradual increase in gamma-radiation dose rate level during about 24 h.&lt;/p&gt;&lt;p&gt;Such a phenomenon is known to occur due to wet deposition of radioactive aerosol particles during rain, namely due to the radon (&lt;sup&gt;222&lt;/sup&gt; Rn) short-lived daughter progeny products (Po-218, Pb-214, Bi-214) attached to atmospheric aerosol particles. The radon (&lt;sup&gt;222&lt;/sup&gt; Rn) daughter progeny involvement is confirmed by simultaneous gamma-spectrometric measurements with SARA AGS711F (Envinet GmbH) at T&amp;#245;ravere station (58&amp;#176; 15' 52,9&quot; N, 26&amp;#176; 27' 42,1&quot;, 72 m), located about 50.3 km west from the J&amp;#228;rvselja SMEAR station. The gamma dose rates showed very similar temporal behavior when both stations were affected by the same air mass with precipitation zone passing over the stations.&lt;/p&gt;&lt;p&gt;To our best knowledge, the details of rain-induced enhancement of gamma-radiation dose rate and atmospheric processes behind the phenomenon are not well known and are worth future investigations. The events of rain induced gamma-radiation dose rate enhancement at J&amp;#228;rvselja SMEAR and T&amp;#245;ravere station are analyzed and discussed in more detail in the presentation and the spatial representativity of the phenomenon is estimated based on the gamma-radiation monitoring network data of Estonian Early Warning System.&lt;/p&gt;


2020 ◽  
Vol 166 ◽  
pp. 06007
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Stanislav Fic ◽  
Hanna Ivashchyshyn

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.


2019 ◽  
Author(s):  
Giulia Stefenelli ◽  
Jianhui Jiang ◽  
Amelie Bertrand ◽  
Emily A. Bruns ◽  
Simone M. Pieber ◽  
...  

Abstract. Box model simulations based on the volatility basis set (VBS) approach were used to assess secondary organic aerosol (SOA) precursors and volatility distributions from residential wood combustion. Emissions were sampled from three different residential stoves at different combustion conditions (flaming vs. smoldering-dominated), aging temperatures (−10 °C, 2 °C and 15 °C), and emission loads, then exposed to hydroxyl (OH) radicals in a smog chamber. Primary emissions of SOA precursor compounds, organic aerosol and their evolution during aging in the smog chamber were monitored by a comprehensive suite of gas and particle instrumentation, including a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) and a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). SOA precursors were classified according to their chemical composition and the identification of the nature of the precursors revealed useful to better constrain model parameters, in particular SOA production rates and molecular characteristics of the condensable gases formed. The general aim of the model was the determination of the parameters describing the volatility distributions of the oxidation products from the different chemical classes considered and their temperature dependence. Novel parameterization methods based on a genetic algorithm (GA) approach allowed estimation of precursor class contributions to SOA and evaluation of the effect of emission variability on SOA yield predictions. Significant differences were observed in the gas-phase composition between smoldering and flaming emissions. Smoldering phase emissions were dominated by oxidized VOCs with less than six carbon atoms family (OVOCc 


1973 ◽  
Vol 244 (134) ◽  
pp. 53-54 ◽  
Author(s):  
C. S. KIANG ◽  
D. STAUFFER ◽  
V. A. MOHNEN

2014 ◽  
Vol 14 (3) ◽  
pp. 1689-1700 ◽  
Author(s):  
H. Kokkola ◽  
P. Yli-Pirilä ◽  
M. Vesterinen ◽  
H. Korhonen ◽  
H. Keskinen ◽  
...  

Abstract. Large-scale atmospheric models, which typically describe secondary organic aerosol (SOA) formation based on chamber experiments, tend to systematically underestimate observed organic aerosol burdens. Since SOA constitutes a significant fraction of atmospheric aerosol, this discrepancy translates into an underestimation of SOA contribution to radiative forcing of atmospheric aerosol. Here we show that the underestimation of SOA yields can be partly explained by wall losses of SOA forming compounds during chamber experiments. We present a chamber experiment where α-pinene and ozone are injected into a Teflon chamber. When these two compounds react, we observe rapid formation and growth of new particles. Theoretical analysis of this formation and growth event indicates rapid formation of oxidized volatile organic compounds (OVOC) of very low volatility in the chamber. If these oxidized organic compounds form in the gas phase, their wall losses will have significant implications on their partitioning between the gas and particle phase. Although these OVOCs of very low volatility contribute to the growth of new particles, their mass will almost completely be depleted to the chamber walls during the experiment, while the depletion of OVOCs of higher volatilities is less efficient. According to our model simulations, the volatilities of OVOC contributing to the new particle formation event can be of the order of 10−5 μg m−3.


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