scholarly journals Oxygenated organic functional groups and their sources in single and submicron organic particles in MILAGRO 2006 campaign

2009 ◽  
Vol 9 (18) ◽  
pp. 6849-6863 ◽  
Author(s):  
S. Liu ◽  
S. Takahama ◽  
L. M. Russell ◽  
S. Gilardoni ◽  
D. Baumgardner

Abstract. Fourier Transform Infrared (FTIR) and X-ray Fluorescence (XRF) were used to measure organic functional groups and elements of submicron particles collected during MILAGRO in March 2006 on three platforms: the Mexico City urban area (SIMAT), the high altitude site at 4010 m (Altzomoni), and the NCAR C130 aircraft. Scanning Transmission X-ray Microscopy (STXM) and Near-Edge X-ray Absorption Fine Structure (NEXAFS) were applied to single particle organic functional group abundance analysis of particles simultaneously collected at SIMAT and C130. Correlations of elemental concentrations showed different groups of source-related elements at SIMAT, Altzomoni, and C130, suggesting different processes affecting the air masses sampled at the three platforms. Cluster analysis resulted in seven distinct clusters of FTIR spectra, with the last three clusters consisting of spectra collected almost exclusively on the C130 platform, reflecting the variety of sources contributing to C130 samples. Positive Matrix Factorization (PMF) of STXM-NEXAFS spectra identified three main factors representing soot, secondary, and biomass burning type spectra. PMF of FTIR spectra resulted in two fossil fuel combustion factors and one biomass burning factor, the former representative of source regions to the northeast and southwest of SIMAT. Alkane, carboxylic acid, amine, and alcohol functional groups were mainly associated with combustion related sources, while non-acid carbonyl groups were likely from biomass burning events. The majority of OM and O/C was attributed to combustion sources, although no distinction between direct emissions and atmospherically processed OM could be identified.

2009 ◽  
Vol 9 (1) ◽  
pp. 4567-4607 ◽  
Author(s):  
S. Liu ◽  
S. Takahama ◽  
L. M. Russell ◽  
S. Gilardoni ◽  
D. Baumgardner

Abstract. Fourier Transform Infrared (FTIR) and X-ray Fluorescence (XRF) were used to measure organic functional groups and elements of submicron particles collected during MILAGRO in March 2006 on three platforms: the Mexico City urban area (SIMAT), the high altitude site at 4010 m (Altzomoni), and the NCAR C130 aircraft. Scanning transmission X-ray Microscopy (STXM) and Near-Edge X-ray Absorption Fine Structure (NEXAFS) were applied to single particle organic functional group abundance analysis of particles simultaneously collected at SIMAT and C130. Correlations of elemental concentrations showed different groups of source related elements at SIMAT, Altzomoni, and C130, suggesting different processes affecting the air masses sampled at the three platforms. Cluster analysis resulted in seven distinct Clusters of FTIR spectra, with the last three clusters consisting of spectra collected almost exclusively on the C130 platform, reflecting the variety of sources contributing to C130 samples. Positive Matrix Factorization (PMF) of NEXAFS-STXM spectra identified three main factors representing soot, secondary, and biomass burning type spectra. PMF of FTIR spectra resulted in three fossil fuel combustion type factors, one biomass burning factor, and one mixed or processed factor. The fossil fuel combustion type factors were found to have the largest contributions to OM, while the processed factor has the largest O/C among all factors. Alkane, carboxylic acid, and amine functional groups were mainly associated with combustion related sources, while alcohol groups were likely from atmospheric processing of mixed sources. While the processed factor has the highest O/C, half of the OM and O/C measured could be attributed directly to fossil fuel combustion sources. Both PMF of NEXAFS-STXM spectra and PMF of FTIR spectra indicate that the combustion type factors are more affected by fluctuations in local sources, while the processed factors are more consistent during the sampling period.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1349
Author(s):  
Tutik Setianingsih ◽  
Bambang Susilo ◽  
Siti Mutrofin ◽  
Bambang Ismuyanto ◽  
Andreas Novan Endaryana ◽  
...  

In this research work, MFe2O4/CNS was prepared using the hydrothermal–microwave method. The influence of cations (M) toward functional groups of composites and their performance in pesticide degradation were studied. Rice husk was pyrolyzed hydrothermally (200 °C, 6 h) and by microwave (800 W, 40 min). Each product was mixed with MCl2 (Zn, Ni, Mn), FeCl3, KOH, and water, and calcined (600 °C, 15 min) to obtain a composite. Characterization by XRD confirmed the MFe2O4/CNS structure. The FTIR spectra of the composites showed different band sharpness related to C-O and M-O. A mixture of dried paddy farm soil, composite, BPMC (buthylphenylmethyl carbamate) pesticide solution (0.25%), and H2O2 solution (0.15%) was kept under dark conditions for 48 h. The solution above the soil was filtered and measured with a UV-Vis spectrophotometer at 217 nm. Applications without the composite and composite–H2O2 were also conducted. The results reveal that dark BPMC degradation with the composite was 7.5 times larger than that without the composite, and 2.9 times larger than that without the composite–H2O2. There were no significantly different FTIR spectra of the soil, soil–BPMC, soil–BPMC-H2O2, and soil–BPMC-H2O2 composite and no significantly different X-ray diffractograms between the soil after drying and soil after application for pesticide degradation using the composite.


2017 ◽  
Vol 17 (11) ◽  
pp. 6853-6864 ◽  
Author(s):  
Jing Zheng ◽  
Min Hu ◽  
Zhuofei Du ◽  
Dongjie Shang ◽  
Zhaoheng Gong ◽  
...  

Abstract. Highly time-resolved in situ measurements of airborne particles were conducted at Mt. Yulong (3410 m above sea level) on the southeastern edge of the Tibetan Plateau in China from 22 March to 14 April 2015. The detailed chemical composition was measured by a high-resolution time-of-flight aerosol mass spectrometer together with other online instruments. The average mass concentration of the submicron particles (PM1) was 5.7 ± 5.4 µg m−3 during the field campaign, ranging from 0.1 up to 33.3 µg m−3. Organic aerosol (OA) was the dominant component in PM1, with a fraction of 68 %. Three OA factors, i.e., biomass burning organic aerosol (BBOA), biomass-burning-influenced oxygenated organic aerosol (OOA-BB) and oxygenated organic aerosol (OOA), were resolved using positive matrix factorization analysis. The two oxygenated OA factors accounted for 87 % of the total OA mass. Three biomass burning events were identified by examining the enhancement of black carbon concentrations and the f60 (the ratio of the signal at m∕z 60 from the mass spectrum to the total signal of OA). Back trajectories of air masses and satellite fire map data were integrated to identify the biomass burning locations and pollutant transport. The western air masses from South Asia with active biomass burning activities transported large amounts of air pollutants, resulting in elevated organic concentrations up to 4-fold higher than those of the background conditions. This study at Mt. Yulong characterizes the tropospheric background aerosols of the Tibetan Plateau during pre-monsoon season and provides clear evidence that the southeastern edge of the Tibetan Plateau was affected by the transport of anthropogenic aerosols from South Asia.


1974 ◽  
Vol 28 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Gary D. Nichols ◽  
David M. Hercules ◽  
Roy C. Peek ◽  
Dennis J. Vaughan

The application of x-ray photoelectron spectroscopy (ESCA) to the study of fiberglass surfaces is reported. Qualitatively, ESCA has been used to show the change in concentration of elements at the surface when fiberglass is subjected to heat and/or acid treatment. Diffusion of calcium to the surface as a function of temperature has been studied. Similarly, leaching of aluminum by acid as a function of pH is reported. The ability of ESCA to detect organic functional groups attached to fiberglass surfaces has been demonstrated for nitrogen and sulfur. Fiberglass coated with organic groups having chelating properties has been shown to extract metals from solution. It has also been demonstrated that ESCA can follow reactions of organic functional groups on glass surfaces, namely sulfonation of an amine.


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