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| Titel |
Geochemistry of aerosols from an urban site, Varanasi, in the Eastern
Indo-Gangetic Plain |
| VerfasserIn |
Kirpa Ram, Stefan Norra, Felix Zirzov, Sunita Singh, Manisha Mehra, Sachichida Nanad Tripathi |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133778
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| Publikation (Nr.) |
 EGU/EGU2016-14426.pdf |
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| Zusammenfassung |
| PM2.5 aerosol samples were collected from an urban site, Varanasi, in the eastern
Indo-Gangetic Plain on weekly basis during 19 March to 29 May 2015 (n=12), along with
daily samples (n=8) during 11 to 18 March 2015 to study the geochemical and morphological
features of aerosols. Samples were collected with a low volume sampler (Leckel
GmbH, Germany) on the terrace of the Institute of Environment and Sustainable
Development building, located in the Banaras Hindu University campus in the southern
part of the city. Samples were analyzed for element concentration by Inductively
Coupled Plasma Mass Spectrometry and particle morphology by Scanning Electron
Microscope.
PM2.5 concentration ranged between 22.3 and 70.5 μgm−3 in daily samples, whereas
those varied between 52.0 and 106 μgm−3 in weekly samples. Lead, potassium, aluminum,
zinc and iron have conspicuously higher concentrations with Pb concentration exceeding
above the annual limit of 50 ngm−3 in four samples. First results show a trend of
corresponding concentrations of chemical elements originated from anthropogenic and
geogenic sources. The biogenic particles are a minor fraction of the total particulate aerosols.
The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back trajectory
analysis of air parcels indicate that the air mass for the low loaded days originate from eastern
directions including the region of the gulf of Bengal, where as high aerosols concentrations in
cases of air masses arriving from north-western direction transporting the air pollutants from
the Gangetic Plain towards Varanasi.
Black carbon (BC) concentration, measured using an microaethalometer (AE-51), exhibit
a strong variability (4.4 to 8.4 μg m−3) in the University campus which are ∼20-40% lower
than those measured in the Varanasi city. The carbon content was found to be high with soot
particles constituting the largest part in these samples and exist as single particle as well as
attachment to other particles. The Cluster analysis shows a mixture of geogenic and
anthropogenic emission sources, though their contribution could not be quantified in the
present study. Thus further investigations are started with continuous aerosol sampling in
Varanasi. |
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