Gschwend%20thesis.pdf

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in a glass flask, stripped onto a charcoal trap, extracted into methylene
chloride, and analyzed by GC. In another experiment, auto and diesel
exhaust were collected in empty glass flasks, Each was connected by a U-
shaped neck to an identical flask containing thoroughly prestripped seawater
(gently stirred). The vapors were then allowed to exchange between the air
and the seawater for i day. The water was then analyzed for C2... and C3-.
benzenes. In order to study the effects of outboard engines, water was collected
near the underwater exhaust of an outboard engine, and this was analyzed for
its isomer distribution. Also, a seawater sample was collected at CD on
September 2 during an afternoon of continual motorboat activity in the
immediate vicinity of CD. The resultant isomer distributions are shown in
figure 4-2.
Although all of the patterns are similar, some important differences
exist. Gasoline and gasoline/oil for motorboats contain less C3-benzenes
than .the heavier fuel oil. Auto exhaust and outboard-exhaust-dissolved-in-
seawater have similar isomer distributions. This may be explained if both
engines produced like exhaust patterns, and this pattern is not changed on
transfer .into seawater bv underwater exhaust systems of outboard engines.
The isomer distribution obtained from exchange of auto exhaust vapor
wi th seawater differs from that of the original exhaust by an enrichment in
the lower-boiling compounds. The pattern of auto-exhaust-dissolved-in~
seawater resembles that observed in CD sample of September 2. This may be
due to boats operating near the dock that
had either inboard ör
inboardloutboard engines. These powerboat types exhaust directly into the
atmosphere, a situation simulated in the lab by placing exhaust gases in
close proximity to seawater and allowing them to dissolve.