960
number of excitation and emission wavelengths depends on apparatus possibilities, as well as on
the main goal of investigator. For rough classification of OP (light/medium/heavy) two excitation
wavelengths are enough. For more precise oil type identification at least three .Aex are needed.
5 - CONCLUSIONS
We can summarize basic spectral features obtained in this work.
- Location of spectrum maximum and spectral shape for oil dispersed in water strongly
corresponds with A ex alteration; Amax for oil film is independent of A ex.
- For natural dissolved organic matter Amax equals 440 nm and practically is constant while Aex is
varying from 200 to 340 nm, but shifts to longer wavelengths if A ex > 340 nm.
- Major bands in fluorescence spectra for oil pollutions in water have the following maxima:
290 nm (Aex<266 nm) - is caused by light OP (gasoline);
340 nm (Aex<308 nm) - is caused by water soluble OP fractions;
>400 nm - due to heavy oils.
-Some additional bands appear in fluorescence spectra using close excitation wavelengths in
spectral region 300...345 nm.
-On the basis of experimental results the new technique for separation of fluorescence of oil
pollution dispersed in water has been suggested.
-Synchronous fluorescence spectra for different oil pollutions in water have been detected using
various differenceAA between Aex and Aem. Synchronous fluorescence spectra withAA=50 nm
characterize type of oil pollution and can be used for oil identification. DOM does not contribute
in this spectrum.
REFERENCES
1. Kung R.T.V., Itzkan I., 1976. Absolute oil conversion efficiency.Applied Optics, 15: 409-415.
2. Visser H., 1979. teledetection of the thickness of oil film on polluted water based on the oil film
fluorescence properties. Applied Optics. 19:1746-1749.
3. Hoge F.E.,1983. Oil film thickness using airborne laser oil fluorescence backscatter. Applied
Optics. 22:3316-3317.
4. Burlamacchi P., Cecchi G., Mazzinghi P., Pantani L., 1983. Performance evaluation of UV
sources for lidar fluorosensing of oil film s Applied Optics.22:48-53.
5. Hengsterman T., Reuter R, 1990. Lidar fluorosensing of mineral oil spills on the sea surface.
Applied Optics.29: 3218-3227.
6. Taer Abd Deidan, Patsayeva S.V., Fadeev V.V., Yuzhakov V.I., 1994 (to be published),
Fluorescent study of thin oil films. Bulletin of Moscow University.
7. Eastwood D., 1981. Modem fluorescence spectroscopy. Ed. Wehry E.L. Plenum Press, New
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