ABSTRACT Shipping activities significantly contribute to global atmospheric pollutant emissions. ... more ABSTRACT Shipping activities significantly contribute to global atmospheric pollutant emissions. Numerous studies have used synchrotron X-ray fluorescence spectroscopy (SRXRF) to identify elemental species in atmospheric particles, yet few studies have applied this technique for assessing PM10-bound chemical species from shipping emissions. In this study, we conducted simultaneous sampling of PM10 at three air quality observation sites located close to Laem Chabang Sea Port (LCSP) from 24 May to 27 June 2020. The PM10 samples were then chemically characterised using SRXRF at the Beam Line 5.1 Wiggler (BL5.1W) in the Siam Photon Source, Synchrotron Light Research Institute (Nakhon Ratchasima, Thailand). We identified unique features in the SRXRF spectra of PM10 samples collected from the site adjacent to LCSP. The average percentage contributions of selected metals at LCSP occurred in the order of Fe > Cu > Te > As > Br > Kr > Mn > Cr > Ni > V > Ti > P > Se > S > Cl, which is in good agreement with the results of previous studies conducted in Bangkok. Although some previous studies highlight the importance of V/Fe as the diagnostic binary ratio that can be used as a chemical proxy for categorizing shipping related particles, this application can be problematic-particularly in the atmospheric environment with high contents of iron-rich dust aerosols. In stead of employing V/Fe, the diagnostic binary ratios of As/V and Se/V can be considered as alternative geochemical tracers for classifying shipping emissions associated aerosols. By applying the concept of enrichment factor (EF), Se is exceedingly enriched in all observatory sites indicating that industrial emissions were the dominant contributor of Se at the ambient air of Lam Chabang. Hierarchical cluster analysis (HCA) successfully classify a group of V, Ti, Ga, and Ni at all sampling sites, which may be caused by shipping activities coupled with industrial emissions.
Organic carbon (OC) is the amount of carbon found in an organic compound. Once entered, the envir... more Organic carbon (OC) is the amount of carbon found in an organic compound. Once entered, the environment OC may cause climate change and effects on public health. The objective of the study was to assess the spatio-temporal trends of OC, climatology, and to develop inventories. The three satellite datasets (MACCity, ACCMIP, RCP 8.5) showed significant different trends in OC levels. Results indicated significantly higher trends in OC distribution during anthropogenic activities and the industrial era as compared with natural sources and the pre-industrial era. The residential and industrial sectors showed higher emission of OC 1.0 × 10−5to 2.5 × 102 Tg/year, respectively as compared with other sectors. Spatial distribution of OC revealed higher levels in bigger cities (Islamabad, Lahore, Karachi, Multan, Punch, and Mardan districts) of Pakistan. The temporal analysis shows irregular increasing trends in OC distribution with the passage of time. Principal component analysis (PCA) revealed that residential OC showed a positive correlation with surface temperature, wind and heat and OC transport, sum, residential, and energy sector with relative humidity in MACCity and RCP 8.5 datasets, respectively. The study indicated that savanna burning and residential sectors were a major contributor to the level of OC. The results will be helpful for the government to devise policies regarding OC management.
Abstract A lack of information on the radiative effects of refractory black carbon (rBC) emitted ... more Abstract A lack of information on the radiative effects of refractory black carbon (rBC) emitted from biomass burning is a significant gap in our understanding of climate change. A custom-made combustion chamber was used to simulate the open burning of crop residues and investigate the impacts of rBC size and mixing state on the particles' optical properties. Average rBC mass median diameters ranged from 141 to 162 nm for the rBC produced from different types of crop residues. The number fraction of thickly-coated rBC varied from 53 to 64%, suggesting that a majority of the freshly emitted rBC were internally mixed. By comparing the result of observed mass absorption cross-section to that calculated with Mie theory, large light absorption enhancement factors (1.7–1.9) were found for coated particles relative to uncoated cores. These effects were strongly positively correlated with the percentage of coated particles but independent of rBC core size. We suggest that rBC from open biomass burning may have strong impact on air pollution and radiative forcing immediately after their production.
The focus of this research was to present a data article associated with organic carbon (OC) and ... more The focus of this research was to present a data article associated with organic carbon (OC) and elemental carbon (EC) preserved in lake sediments. Descriptive statistics were applied in this dataset. Sediment cores were sliced immediately at the following layers: 0–20; 20–40; 40–60; 60–80; 80–100; 100–120; 120–140; 140–160; 160–180; 180–200; 200–220; 220–240; 240–260; 260–280; 280–300; 300–320; 320–340; 340–360; 360–380; 380–400; 440–460; 460–480; 480–500; 500–520; 520–540; 540–560 and 560–580 mm of depth. Chemical analysis of OC (i.e. OC1, OC2, OC3, OC4), EC (i.e. EC1, EC2, EC3), and the pyrolyzed organic carbon (OP) (i.e. OP1, OP2, OP3, OP4, OP5, OP6, Char, Soot) contents was conducted by using a DRI Model 2001 Thermal/Optical Carbon Analyzer. The chemical characterization coupled with statistical analysis reveal that vehicle exhausts are the most prominent factor governing OC/EC data detected in core sediments. These data underline some noticeable concerns associated with ecotoxicology and environmental safety of residents surrounding the Songkhla Lake.
ABSTRACT Shipping activities significantly contribute to global atmospheric pollutant emissions. ... more ABSTRACT Shipping activities significantly contribute to global atmospheric pollutant emissions. Numerous studies have used synchrotron X-ray fluorescence spectroscopy (SRXRF) to identify elemental species in atmospheric particles, yet few studies have applied this technique for assessing PM10-bound chemical species from shipping emissions. In this study, we conducted simultaneous sampling of PM10 at three air quality observation sites located close to Laem Chabang Sea Port (LCSP) from 24 May to 27 June 2020. The PM10 samples were then chemically characterised using SRXRF at the Beam Line 5.1 Wiggler (BL5.1W) in the Siam Photon Source, Synchrotron Light Research Institute (Nakhon Ratchasima, Thailand). We identified unique features in the SRXRF spectra of PM10 samples collected from the site adjacent to LCSP. The average percentage contributions of selected metals at LCSP occurred in the order of Fe > Cu > Te > As > Br > Kr > Mn > Cr > Ni > V > Ti > P > Se > S > Cl, which is in good agreement with the results of previous studies conducted in Bangkok. Although some previous studies highlight the importance of V/Fe as the diagnostic binary ratio that can be used as a chemical proxy for categorizing shipping related particles, this application can be problematic-particularly in the atmospheric environment with high contents of iron-rich dust aerosols. In stead of employing V/Fe, the diagnostic binary ratios of As/V and Se/V can be considered as alternative geochemical tracers for classifying shipping emissions associated aerosols. By applying the concept of enrichment factor (EF), Se is exceedingly enriched in all observatory sites indicating that industrial emissions were the dominant contributor of Se at the ambient air of Lam Chabang. Hierarchical cluster analysis (HCA) successfully classify a group of V, Ti, Ga, and Ni at all sampling sites, which may be caused by shipping activities coupled with industrial emissions.
Organic carbon (OC) is the amount of carbon found in an organic compound. Once entered, the envir... more Organic carbon (OC) is the amount of carbon found in an organic compound. Once entered, the environment OC may cause climate change and effects on public health. The objective of the study was to assess the spatio-temporal trends of OC, climatology, and to develop inventories. The three satellite datasets (MACCity, ACCMIP, RCP 8.5) showed significant different trends in OC levels. Results indicated significantly higher trends in OC distribution during anthropogenic activities and the industrial era as compared with natural sources and the pre-industrial era. The residential and industrial sectors showed higher emission of OC 1.0 × 10−5to 2.5 × 102 Tg/year, respectively as compared with other sectors. Spatial distribution of OC revealed higher levels in bigger cities (Islamabad, Lahore, Karachi, Multan, Punch, and Mardan districts) of Pakistan. The temporal analysis shows irregular increasing trends in OC distribution with the passage of time. Principal component analysis (PCA) revealed that residential OC showed a positive correlation with surface temperature, wind and heat and OC transport, sum, residential, and energy sector with relative humidity in MACCity and RCP 8.5 datasets, respectively. The study indicated that savanna burning and residential sectors were a major contributor to the level of OC. The results will be helpful for the government to devise policies regarding OC management.
Abstract A lack of information on the radiative effects of refractory black carbon (rBC) emitted ... more Abstract A lack of information on the radiative effects of refractory black carbon (rBC) emitted from biomass burning is a significant gap in our understanding of climate change. A custom-made combustion chamber was used to simulate the open burning of crop residues and investigate the impacts of rBC size and mixing state on the particles' optical properties. Average rBC mass median diameters ranged from 141 to 162 nm for the rBC produced from different types of crop residues. The number fraction of thickly-coated rBC varied from 53 to 64%, suggesting that a majority of the freshly emitted rBC were internally mixed. By comparing the result of observed mass absorption cross-section to that calculated with Mie theory, large light absorption enhancement factors (1.7–1.9) were found for coated particles relative to uncoated cores. These effects were strongly positively correlated with the percentage of coated particles but independent of rBC core size. We suggest that rBC from open biomass burning may have strong impact on air pollution and radiative forcing immediately after their production.
The focus of this research was to present a data article associated with organic carbon (OC) and ... more The focus of this research was to present a data article associated with organic carbon (OC) and elemental carbon (EC) preserved in lake sediments. Descriptive statistics were applied in this dataset. Sediment cores were sliced immediately at the following layers: 0–20; 20–40; 40–60; 60–80; 80–100; 100–120; 120–140; 140–160; 160–180; 180–200; 200–220; 220–240; 240–260; 260–280; 280–300; 300–320; 320–340; 340–360; 360–380; 380–400; 440–460; 460–480; 480–500; 500–520; 520–540; 540–560 and 560–580 mm of depth. Chemical analysis of OC (i.e. OC1, OC2, OC3, OC4), EC (i.e. EC1, EC2, EC3), and the pyrolyzed organic carbon (OP) (i.e. OP1, OP2, OP3, OP4, OP5, OP6, Char, Soot) contents was conducted by using a DRI Model 2001 Thermal/Optical Carbon Analyzer. The chemical characterization coupled with statistical analysis reveal that vehicle exhausts are the most prominent factor governing OC/EC data detected in core sediments. These data underline some noticeable concerns associated with ecotoxicology and environmental safety of residents surrounding the Songkhla Lake.
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