Organic aerosol is a large and important fraction of PM1 and has great impact on human health, especially because of some of the compounds have proved to be mutagens or carcinogens. Along with fast economical growth, the air quality in Beijing has suffered severe deterioration, with PM being one of the top pollutants.
Organic matter is the most abundant fraction in fine particles in Beijing, accounting for 30-50% of the total mass, indicating its key role in air pollution control. Because the chemical compositions and sources of OA are complex (they can be classified as either primary OA (POA), from direct emissions, or secondary OA (SOA), from the oxidation of gas-phase precursors), the related studies on their chemical and physical characteristics have become difficult and a recent focus point. High time-resolution online measurements are needed to gain insight into aerosol chemical characteristics, sources and processes.
Professor Wang Yuesi and Dr. Liu Quan from State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences performed the online observation of chemical compositions and size distributions of OA with a HR-ToF-AMS to reveal the variation regularity of organic aerosols in Bejing winter. Meanwhile, based on the data of the mass spectra of organic compounds, major sources of OA were resolved by positive matrix factorisation (PMF). Their work, entitled "In situ measurement of PM1 organic aerosol in Beijing winter using a high-resolution aerosol Mass Spectrometer", was published in Chinese Science Bulletin, 2012, Vol 57(7).
The mean OA mass concentration was 20.9±25.3 ìg/m3 during this campaign, varying between 1.9 and 284.6 ìg/m3. The average mass-based size distributions of OA present a prominent accumulation mode peaking at approximately 450 nm. During this study, the average H/C, O/C and N/C (molar ratio) were 1.70, 0.17, and 0.005, respectively, corresponding to an OM/OC ratio (mass ratio of organic matter to organic carbon) of 1.37. The diurnal pattern of O/C was consistent with that of OM/OC and displayed a typical photochemical characteristic.
Positive Matrix Factorisation (PMF) analysis of the organic mass spectral dataset differentiated the OA into three components (Figure 1): hydrocarbon-like (HOA), cooking-related (COA), and oxygenated (OOA) organic aerosols, which, on average, accounted for 26.9%, 49.7% and 23.4%, respectively. The sum of HOA and COA could be regarded as POA, and the OOA corresponded to aged SOA. The POA is a dominant component of OA in Beijing winter, with a large percentage of 76.6%. The large contribution of COA in the POA mass indicates its key role in PM1 pollution control in Beijing.
See the article: Liu Quan, Sun Yang, Hu Bo et al. In situ measurement of PM1 organic aerosol in Beijing winter using a high-resolution aerosol Mass Spectrometer. Chinese Science Bulletin, 2012, 57 (7): 819-826.
Liu Quan | EurekAlert!
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences