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Increasing public concern regarding air quality has led to the development of efficient aerosol-monitoring techniques. Among the various aerosol measurement instruments based on electrical methods, in this study, an electrical cascade impactor (ECI) was designed and fabricated in our laboratory and was used to measure the real-time size distributio...
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... DLPI (Dekati, Fig. S2) was used to determine the PM concentration and mass-size distribution in the dilution tunnel via isokinetic sampling in the middle of the flue gas stream. The sampling was made with regards to the EN 13284-1 (BSI, 2001), ISO 11338-1 (ISO, 2003) and EN ISO 23210 (ISO, 2009) standards, which do not include the sampling of the PM 1 and PM 0.1 fractions (Drastichová, 2015). The flue gas was cooled down in the dilution tunnel ahead of the DLPI. The DLPI was heated during collection to a temperature of 80°C to prevent condensation of flue gases and to be closer to the temperature of flue gases in the dilution tunnel. Any diluter was applied ahead of the DLPI. The DLPI enables the sorting of the PM into thirteen different sized fractions with diameters of approximately 0.03 µm to 10 µm. The sums of the particle masses on the individual collection substrates provide the distribution of the PM fractions: PM 0.1 (0-2 stage), PM 1 (0-7 stage), PM 2.5 (0-9 stage) and PM 10 (0-13 stage), Table S3. Behind the DLPI was a polyurethane foam (PUF) for the collection of PAHs in the gaseous phase. The use of PUF is meaningful because, for example, for benzo [a]pyrene, the vapor fraction can represent a significant amount of its total concentration. PUF is an efficient sorbent due to its relatively high capacity, low cost and low impedance (Paolini et al., 2016). The correctness of the results from the DLPI was compared in this study with the results from a cyclone (Tecora) that was simultaneously used in parallel to determine the PM concentration and mass-size distribution. The time coverage of the DLPI in comparison with the time coverage of the cyclone is summarized in Table S4. The results of the EF (emission factor) PAHs from the cyclone are presented in detail in our previous work (Horak et al., ...
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... was reported in the literature ( Sahu et al., 2008;Lisouza et al., 2013) that PAHs with a higher molecular weight (MW > 228 g mol -1 ) preferentially segregate into fine particles. The DLPI data showed that 4 PAHs with MW > 228 g mol -1 were primarily detected (more than 50%) on PM 1 except for tests no. 4, 20, 24 and 25, in which the 4 PAHs were mainly (more than 50%) detected in the gas phase (PUF), and for test no. 3, in which the 4 PAHs were also detected on larger PM and in PUF (Fig. 1, Table S4). The cyclone data showed that 4 PAHs were mostly detected on PM 2.5 , except for test no. 18 in which the 4 PAHs were mainly detected in PUF (Fig. 2, Table ...
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... results described in the main text of the article are presented in graphs and tables in the Supplementary Material. The schematic diagrams of the tested combustion devices are shown in Fig. S1. The photo of the Dekati Low-Pressure Impactor (DLPI, Dekati) is presented in Fig. ...
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... DLPI (Dekati, Fig. S2) was used to determine the PM concentration and mass-size distribution in the dilution tunnel via isokinetic sampling in the middle of the flue gas stream. The sampling was made with regards to the EN 13284-1 (BSI, 2001), ISO 11338-1 (ISO, 2003) and EN ISO 23210 (ISO, 2009) standards, which do not include the sampling of the PM 1 and ...
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... no. 4, 20, 24 and 25, in which the 4 PAHs were mainly (more than 50%) detected in the gas phase (PUF), and for test no. 3, in which the 4 PAHs were also detected on larger PM and in PUF (Fig. 1, Table S4). The cyclone data showed that 4 PAHs were mostly detected on PM 2.5 , except for test no. 18 in which the 4 PAHs were mainly detected in PUF (Fig. 2, Table ...
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The particle size distribution of urban aerosols is typically dominated by ultrafine particles (UFP) originating from local sources such as traffic and industrial emissions. Due to their negligible mass they are clearly underrepresented by legislative PM10 mass measurements. This is one reason why their contribution to urban air quality is better c...
Citations
... The electrical low-pressure cascade impactor was developed further for achieving higher resolution with 100 or 500 size fractions (i.e. HR-ELPI+) (Saari S. et al., 2018) or measuring nanoparticle mass concentration using a wire-to-rode corona charger to eliminate the new particle formation which may occur in the pin-to-plate corona charger (Han J. et al., 2018). ...
Inertial impactors are applied widely to classify particulate matters (PMs) and nanoparticles (NPs) with desired aerodynamic diameters for further analyses due to their sharp cutoff characteristics, simple design, easy operation, and high collection ability. A few hundred papers have been published since the 1860s that addressed the characteristics and applications of the inertial impactors. In the last 30 years, our group has also carried out lots of studies to contribute to the design and the improvement of inertial impactors. With our understanding of inertial impactors, this article reviews previous studies of some typical types of the inertial impactors including conventional impactors, cascade impactors, and virtual impactors and the parameters for design consideration of these devices. The article also reviews some applications of the inertial impactors, which are mass concentration measurement, mass and number distribution measurement, personal exposure measurement, particulate matter control, and powder classification. The synthesized knowledge of the inertial impactor in this study can help researchers to design an inertial impactor with an accurate cutoff diameter, a sharp collection efficiency curve, and no particle bounce and particle overloading effects for long-term use for PM classification and control purposes.
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Air pollutants can cause a variety of environmental and health problems, and several epidemiological and clinical studies have investigate the association of diseases with air pollution. Air pollutants include fine particles and ultrafine particles, which show complex aspects depending on time and space. Therefore, a portable system for measuring fine particles is required. In this study, we developed a portable system to measure the number concentration, mass concentration, and effective density of PM10, which are important measures of fine particles. Current devices used to measure the effective density of particles are either large or only able to measure target particles at the nanoscale. In this study, an Optical Particle Counter (OPC) and a one-stage Quartz Crystal Microbalance (QCM) impactor were used to compose a PM10 multilateral measurement system to calculate the effective density of PM10. OPC is a small device that measures the number concentration of particles, and the QCM impactor measures the mass concentration of particles. Currently available QCM impactors for particle measurement are large devices. Therefore, we miniaturized it in the form of a one-stage impactor. The QCM was installed on an impaction plate to collect the particles. Through the developed system, the number and mass concentrations of input particles were simultaneously measured, and their effective density was calculated using the measured concentrations. Finally, outdoor air monitoring was performed, and the obtained measurements were validated by comparing them with the measurements of reference devices. A difference of 4.7% and 11% were obtained for mass and number concentrations, respectively. Therefore, the effective density of PM10 was successfully calculated.
