Kohlenwasserstoffe

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Kohlenwasserstoffe

• Rauch, Ruß, Methan, Erdöl

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Umweltverhalten organischer Schadstoffe   3.      
     Kohlenwasserstoffe 3.1.        Rauch,
Ruß 3.2.        Methan 3.3.        Erdöl 3.3.1    
  Zusammensetzung
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Rauch, Ruß            Rauch- Kohlenstoffpartikel
gt 10 µm        Ruß Kohlenstoffpartikel lt 1
µm        Rußflocken (schweres Heizöl) 50-100
µm  
EG-Richtlinien zur Staubemission (EEC 80/779)
Jahresmittelwert 80 µg/m³ Mittelwert im Winter
(1.10.-31.3.) 130 µg/m³ Maximalwert (98 der
Tagesmittel 250 µg/m³ müssen unter diesem Wert
liegen)

nach Alloway Ayres Schadstoffe in der Umwelt
Spektrum, 1996
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Daten aus Bliefert, 1997
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Figure from Baird, 1999
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Senken für Methan   1)  Chemische Reaktion mit
OH-Radikalen in der Troposphäre OH-Radikale
entstehen bei Photolyse von Ozon (O2 angeregter
Sauerstoff)   O. H2O ? HO. .OH   In reiner
Luft Umsetzung mit Kohlenmonoxid   HO. CO ? H.
CO2   In verunreinigter Luft Umsetzung mit
Methan, Bildung des reaktiven Methylradikals   HO.
CH4 ? .CH3 H2O   Reaktion mit Sauerstoff
unter Bildung von Methylperoxyradikal, Reaktion
mit NO zu einem Alkoxyradikal   CH3-O-O. NO ?
CH3O. NO2   Umwandlung in Carbonylverbindung
durch Abgabe eines H-Atoms   CH3O. ? H2CO .H
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Daten aus Bliefert, 1997
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Data from Conell, 1997
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Petroleum
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Light Heavy Crude Oil Depending on the mixture
of hydrocarbon molecules, crude oil varies in
color, composition and consistency. Different
oil-producing areas yield significantly different
varieties of crude oil. The words "light" and
"heavy" describe a crude oils density and its
resistance to flow (viscosity).Some, which are
low in metals and sulfur content, light in color
and consistency, and flow easily, are known as
"light." Less expensive, low-grade crude oils,
which are higher in metals and sulfur content,
and must be heated to become fluid, are known as
"heavy." The term "sweet" is used to describe
crude oil that is low in malodorous sulfur
compounds such as hydrogen sulfide and
mercaptans, and the term "sour" is used to
describe crude oil containing high malodorous
sulfur compounds
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Figure from Conell, 1997
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Figure from Conell, 1997
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Data from Conell, 1997
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Figure from Conell, 1997
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Exxon Valdez (1989)
http//www.foilex.com/bilder/tcdae/exxonvaldez.GIF
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Consequences
http//www.quarks.de/dyn/pics/17504-17698-2-kap6_2
.jpg
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Data from Conell, 1997
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Different oils do not behave in the same manner
when released onto the sea. This is due to
differences in the physico-chemical composition.
Studies and experiments have shown that the rate
of weathering may vary greatly for various oil
types under different weather conditions . This
was also clearly demonstrated in the dramatically
different behaviour of the oils spilled in the
Exxon Valdez incident in Alaska in 1989 and in
the Braer incident off Shetland in 1993.
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At first, it looked as if this oil spill would be
on par (in terms of damage) with the wreck of the
Exxon Valdez in 1989. However, the accident
turned out to be relatively harmless even though
it was the twelfth largest spill in history ("A
Disaster That Wasn't," Discover, January 1994, p.
69.). The damage to the wildlife was as follows
"The official death tolls -- the number of
carasses recovered -- included 1,542 seabirds,
several thousand pounds of commercially farmed
salmon, 10 gray seals, and 4 otters. Two of the
otters were run over by a camera crew covering
the spill, however, and the other two probably
died of old age"
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Data from Conell, 1997
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http//en.wikipedia.org/wiki/Colloid
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Figure from Conell, 1997
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Figure from Conell, 1997
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Figure from Conell, 1997
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Data from Conell, 1997
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Key points

• Sources
• Components
• Physical
• Chemical
• n- vs branched
• Biota
• Ar hydrocarbons and biota
• toxicity