Post-graduate theses
Current Record: 4767 of 6511
|
|
| Identifier |
uch.chemistry.msc//2001MST0716 |
| Title |
Μελέτη της φορμαλδεΰδης στην υγρή και αέρια φάση στην περιοχή της Ανατολικής Μεσογείου |
|
Author
|
Οικονόμου, Κωνσταντίνα
|
| Abstract |
Formaldehyde (HCHO) is a labile organic compound involved in several important processes occurring within the troposphere. Atmospheric deposition is a significant source of HCHO since concentrations in rainwater are proposed to be up to three orders of magnitude higher than in surface waters. Despite the significance of HCHO to the chemistry of the troposphere very few works have been addressed the occurrence and variability of this compound in rain. Especially no work has been reported for the Mediterranean or the Southern Europe. We report in this study HCHO concentrations measured in 66 rain samples in Heraklion (Crete) from September 1999 to May 2000 (i.e. during the rainy period). Concentrations ranged from 12.7 to 334 ppb, in the range of HCHO levels reported at other locations world-wide. The volume-weighted annual average rainwater formaldehyde concentration was 91.6 ppb and comprised approximately 3% of the dissolved total carbon. Formaldehyde levels in rain water were found to be air-masses origin dependant since the per event deposition of HCHO when air masses originated from Europe or Balkans were 3-4 times higher compared to that from Africa or from marine sectors. Formaldehyde was positively correlated with formic acid, non-sea-salt sulfate, nitrate and ammonium. Ambient concentrations of HCHO measured during EL-CID campaign at Finokalia (Crete) in a total of 214 samples. HCHO concentrations ranged between 0.18 and 1.01 ppbv with an overall average value of 0.54 ppbv. A diurnal variation has been observed which exhibits the daytime photo-oxidation production and destruction and the night-time production from the oxidation of dimethylsulfide (DMS) through nitrate (NO3 . ) radicals. Very good correlation was observed between HCHO, Black Carbon (BC) and carbon monoxide (CO) during the biomass burning events which were occurred all over Greece during a period of the campaign.
|
| Language |
Greek |
| Issue date |
2001-07-01 |
| Collection
|
School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses
|
|
|
Type of Work--Post-graduate theses
|
| Permanent Link |
https://elocus.lib.uoc.gr//dlib/e/3/2/metadata-dlib-2001MST0716.tkl
|
| Views |
196 |
|
Digital Documents
|
|
|
Collections
