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Identifier

000401784

Title

Μη-Μεθανικοί υδρογονάθρακες (C2-C6) στην ατμόσφαιρα των Αθηνών : ρόλος της καύσης βιομάζας τους χειμερινούς μήνες

Alternative Title

Non-Methane hydrocarbons at the atmosphere of the greater athens area

Author

Πανοπούλου, Αναστασία Π.

Thesis advisor

Μιχαλόπουλος, Νικόλαος

Reviewer

Κανακίδου, Μαρία
Λιακάκου, Ελένη

Abstract

The following work presents the first results of high-resolution and long-term measurements of non-methane hydrocarbons (NMHCs) in the atmosphere of the Great Athens Area (GAA). For their analysis an automate Gas Chromatography system based on the cryofocusing technique was used, which was coupled with a Flame Ionization Detector (GC – FID). The measurements took place from October till December 2015. The concentrations of NMHCs show a significant increase from October to December. Especially in December, it is apparent a duplication or triplication of their respective levels. The increase is attributed to their emission from wood burning for domestic heating, which occurs during winter. Additionally, they exhibit a well defined daily cycle, which is characterized by a morning maximum, followed by an extended noon minimum, and eventually an extended night maximum. The levels of the maximum are different each month, but on December the night maximum is higher compared with the morning maximum. In order to investigate the contribution of wood burning to the concentrations of NMHCs, the analysis period is divided into no-wood burning (nwb) and wood burning (wb) period, according to the increase of the concentration of carbon monoxide (CO) and black carbon (BC). At wb period there is an increase of the concentrations from about 50% to 70% (for example, butane’s concentration increases from 2 ppb to 6 ppb), while there is no difference between the concentrations of workdays and holidays. From the comparison of the trend between the NMHCs daily cycles and the daily cycles of the BC fractions from fossil fuel burning and wood burning (BC_ff and BC_wb respectively), it is indicated that the morning maximum of the concentrations is attributed to the fossil fuel burning exclusively. However, the night maximum is due to both fossil fuel and wood burning. Finally, from the slopes of the regression between NMHCs with BC_ff and BC_wb respectively, we came to the result that emission rate of NMHCs from fossil fuel and wood burning is the same the wb period. An exception seems to be the NMHCs with less than 3 carbon atoms, which presents a little higher emission rates from wood burning. Additionally, since there is no difference of the emission rates from the fossil fuel burning in both periods (nwb and wb), we conclude that during the wb period a new source of NMHCs, wood burning, is added to the previous sources, and also having the same intensity of emissions.

Language

Greek

Subject

Time variation

Wood burning

Καύση ξύλου

Χρονική διακύμανση

Issue date

2016-07-22

Collection

School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses

Type of Work--Post-graduate theses