Hygroscopic growth of simulated lung fluid aerosol particles under ambient environmental conditions

2021 ◽  
Vol 57 (26) ◽  
pp. 3243-3246
Author(s):  
James F. Davies ◽  
Chelsea L. Price ◽  
Jack Choczynski ◽  
Ravleen Kaur Kohli

The hygroscopicity of simulated lung fluid particles is reported. Efflorescence and deliquescence transitions were measured, and phase hysteresis was observed. A multiphase particle is predicted to form under dry and low RH conditions.

Author(s):  
Snezana Radivojev ◽  
Gerfried Luschin-Ebengreuth ◽  
Joana T. Pinto ◽  
Peter Laggner ◽  
Alessandro Cavecchi ◽  
...  

2006 ◽  
Vol 6 (12) ◽  
pp. 4519-4527 ◽  
Author(s):  
H. Wex ◽  
A. Kiselev ◽  
M. Ziese ◽  
F. Stratmann

Abstract. A calibration for LACIS (Leipzig Aerosol Cloud Interaction Simulator) for its use as a CCN (cloud condensation nuclei) detector has been developed. For this purpose, sodium chloride and ammonium sulfate particles of known sizes were generated and their grown sizes were detected at the LACIS outlet. From these signals, the effective critical super-saturation was derived as a function of the LACIS wall temperature. With this, LACIS is calibrated for its use as a CCN detector. The applicability of LACIS for measurements of the droplet activation, and also of the hygroscopic growth of atmospheric aerosol particles was tested. The activation of the urban aerosol particles used in the measurements was found to occur at a critical super-saturation of 0.46% for particles with a dry diameter of 75 nm, and at 0.42% for 85 nm, respectively. Hygroscopic growth was measured for atmospheric aerosol particles with dry diameters of 150, 300 and 350 nm at relative humidities of 98 and 99%, and it was found that the larger dry particles contained a larger soluble volume fraction of about 0.85, compared to about 0.6 for the 150 nm particles.


Tellus B ◽  
1992 ◽  
Vol 44 (5) ◽  
pp. 556-569 ◽  
Author(s):  
I. B. Svenningsson ◽  
H.-C. Hansson ◽  
A. Wiedensohler ◽  
J. A. Ogren ◽  
K. J. Noone ◽  
...  

2007 ◽  
Vol 7 (1) ◽  
pp. 211-222 ◽  
Author(s):  
M. Ehn ◽  
T. Petäjä ◽  
H. Aufmhoff ◽  
P. Aalto ◽  
K. Hämeri ◽  
...  

Abstract. The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic compound, was monitored. The focus was mainly on days with new particle formation by nucleation. The measured hygroscopic growth factors (GF) correlated positively with the gaseous phase sulfuric acid concentrations. The smaller the particles, the stronger the correlation, with r=0.20 for 50 nm and r=0.50 for 10 nm particles. The increase in GF due to condensing sulfuric acid is expected to be larger for particles with initially smaller masses. During new particle formation, the changes in solubility of the new particles were calculated during their growth to Aitken mode sizes. As the modal diameter increased, the solubility of the particles decreased. This indicated that the initial particle growth was due to more hygroscopic compounds, whereas the later growth during the evening and night was mainly caused by less hygroscopic or even hydrophobic compounds. For all the measured sizes, a diurnal variation in GF was observed both during days with and without particle formation. The GF was lowest at around midnight, with a mean value of 1.12–1.24 depending on particle size and if new particle formation occurred during the day, and increased to 1.25–1.34 around noon. This can be tentatively explained by day- and nighttime gas-phase chemistry; different vapors will be present depending on the time of day, and through condensation these compounds will alter the hygroscopic properties of the particles in different ways.


2020 ◽  
Vol 12 (5) ◽  
pp. 785 ◽  
Author(s):  
Tong Wu ◽  
Zhanqing Li ◽  
Jun Chen ◽  
Yuying Wang ◽  
Hao Wu ◽  
...  

Water uptake by aerosol particles alters its light-scattering characteristics significantly. However, the hygroscopicities of different aerosol particles are not the same due to their different chemical and physical properties. Such differences are explored by making use of extensive measurements concerning aerosol optical and microphysical properties made during a field experiment from December 2018 to March 2019 in Beijing. The aerosol hygroscopic growth was captured by the aerosol optical characteristics obtained from micropulse lidar, aerosol chemical composition, and aerosol particle size distribution information from ground monitoring, together with conventional meteorological measurements. Aerosol hygroscopicity behaves rather distinctly for mineral dust coarse-mode aerosol (Case I) and non-dust fine-mode aerosol (Case II) in terms of the hygroscopic enhancement factor, f β ( R H , λ 532 ) , calculated for the same humidity range. The two types of aerosols were identified by applying the polarization lidar photometer networking method (POLIPHON). The hygroscopicity for non-dust aerosol was much higher than that for dust conditions with the f β ( R H , λ 532 ) being around 1.4 and 3.1, respectively, at the relative humidity of 86% for the two cases identified in this study. To study the effect of dust particles on the hygroscopicity of the overall atmospheric aerosol, the two types of aerosols were identified and separated by applying the polarization lidar photometer networking method in Case I. The hygroscopic enhancement factor of separated non-dust fine-mode particles in Case I had been significantly strengthened, getting closer to that of the total aerosol in Case II. These results were verified by the hygroscopicity parameter, κ (Case I non-dust particles: 0.357 ± 0.024; Case II total: 0.344 ± 0.026), based on the chemical components obtained by an aerosol chemical speciation instrument, both of which showed strong hygroscopicity. It was found that non-dust fine-mode aerosol contributes more during hygroscopic growth and that non-hygroscopic mineral dust aerosol may reduce the total hygroscopicity per unit volume in Beijing.


2017 ◽  
Vol 10 (3) ◽  
pp. 1269-1280 ◽  
Author(s):  
Sergey S. Vlasenko ◽  
Hang Su ◽  
Ulrich Pöschl ◽  
Meinrat O. Andreae ◽  
Eugene F. Mikhailov

Abstract. A tandem arrangement of Differential Mobility Analyser and Humidified Centrifugal Particle Mass Analyser (DMA-HCPMA) was developed to measure the deliquescence and efflorescence thresholds and the water uptake of submicron particles over the relative humidity (RH) range from 10 to 95 %. The hygroscopic growth curves obtained for ammonium sulfate and sodium chloride test aerosols are consistent with thermodynamic model predictions and literature data. The DMA-HCPMA system was applied to measure the hygroscopic properties of urban aerosol particles, and the kappa mass interaction model (KIM) was used to characterize and parameterize the concentration-dependent water uptake observed in the 50–95 % RH range. For DMA-selected 160 nm dry particles (modal mass of 3.5 fg), we obtained a volume-based hygroscopicity parameter, κv ≈  0.2, which is consistent with literature data for freshly emitted urban aerosols.Overall, our results show that the DMA-HCPMA system can be used to measure size-resolved mass growth factors of atmospheric aerosol particles upon hydration and dehydration up to 95 % RH. Direct measurements of particle mass avoid the typical complications associated with the commonly used mobility-diameter-based HTDMA technique (mainly due to poorly defined or unknown morphology and density).


Atmosphere ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 340 ◽  
Author(s):  
Zhi-Jie Tang ◽  
Xin Hu ◽  
Jun-Qin Qiao ◽  
Hong-Zhen Lian

20 sets of indoor and outdoor size-segregated aerosol (SSA) samples (180 foils) were collected synchronously by using two 8 Stage Non-Viable Cascade Impactor from an office room in the central region of the megacity-Nanjing, China in winter and spring in 2016. The mass size distribution of SSAs was bimodal for outdoor SSAs and unimodal for indoor in both winter and spring. The crustal elements, such as K, Ca, Mg and Fe, were mainly distributed in the coarse fractions of SSAs while toxic elements such as As, Cd, Pb and Sb were enriched more in the fine fractions in both winter and spring. Moreover, indoor/outdoor (I/O) concentration ratios of SSAs and inorganic elements indicated the penetration of outdoor fine fractions of SSAs into indoor air. As, Pb, V and Mn showed higher inhalation bioaccessibility extracted by the artificial lysosomal fluid (ALF); while V, As, Sr and Cd showed higher inhalation bioaccessibility using the simulated lung fluid (SLF), suggesting differences in elemental inhalation bioaccessibility between ALF and SLF extraction. There were similar potential carcinogenic and accumulative non-carcinogenic risks via inhalation exposure to indoor and outdoor particle-bound toxic elements based on their bioaccessible concentrations. Therefore, the potential health risks to human posed by toxic elements in office rooms cannot be neglected via inhalation exposure of the fine airborne particles.


2018 ◽  
Author(s):  
Josef Gasteiger ◽  
Matthias Wiegner

Abstract. The spatiotemporal distribution and characterization of aerosol particles are usually determined by remote sensing and optical in-situ measurements. These measurements are indirect with respect to microphysical properties and thus inversion techniques are required to determine the aerosol microphysics. Scattering theory provides the link between microphysical and optical properties; it is not only needed for such inversions but also for radiative budget calculations and climate modeling. However, optical modeling can be very time consuming, in particular if non-spherical particles or complex ensembles are involved. In this paper we present the MOPSMAP package (modeled optical properties of ensembles of aerosol particles) which is computationally fast for optical modeling even in case of complex aerosols. The package consists of a data set of pre-calculated optical properties of single aerosol particles, a Fortran program to calculate the properties of user-defined aerosol ensembles, and a user-friendly web interface for online calculations. Spheres, spheroids, and a small set of irregular particle shapes are considered over a wide range of sizes and refractive indices. MOPSMAP provides the fundamental optical properties assuming random particle orientation, including the scattering matrix for the selected wavelengths. Moreover, the output includes tables of frequently used properties such as the single scattering albedo, the asymmetry parameter or the lidar ratio. To demonstrate the wide range of possible MOPSMAP applications a selection of examples is presented, e.g., dealing with hygroscopic growth, mixtures of absorbing and non-absorbing particles, the relevance of the size equivalence in case of non-spherical particles, and the variability of volcanic ash microphysics. The web interface is designed to be intuitive for expert and non-expert users. To support users a large set of default settings is available, e.g., several wavelength-dependent refractive indices, climatologically representative size distributions, and a parameterization of hygroscopic growth. Calculations are possible for single wavelengths or user-defined sets (e.g., of specific remote sensing application). For expert users more options for the microphysics are available. Plots for immediate visualization of the results are shown. The complete output can be downloaded for further applications. All input parameters and results are stored in the user’s personal folder so that calculations can easily be reproduced. The MOPSMAP package is available on request for offline calculations, e.g., when large numbers of different runs for sensitivity studies shall be made.


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