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The exhaust fume from internal combustion engines has been one of the largest pollutants in
aquatic and atmospheric systems in the world1
. The formation of oxides of nitrogen under high
pressures and temperatures during the combustion process of the engine initiates a chain of
reactions with volatile organic compounds (VOC’s) in the presence of UV light to form
photochemical smog in the atmosphere3
. This research investigates the possibility to reduce the
photochemical smog by removing a water soluble fraction of diesel fumes. In the general
experimental set up of this research, the diesel exhaust line that comes out from Toyota 2C
diesel engine is connected to a smog chamber equipped with UV light source. It was measured
that the pH of the water drops to 2.9 from 5.8 in 20 min during the function of diesel engine at
idle mode. The Fig. 1(a) shows the UV-Vis spectrum of diesel fumes directly purged into
distilled water samples. It shows the dissolution of some VOC’s in water. The Fig. 1(b)
represents the UV-VIS spectrum of diesel fumes that initially go through the smog chamber
and then purged into cyclohexane. Fig.1(c) represents the UV-VIS spectrum of the samples
that were collected after the diesel fumes were fed into the water tank prior to sending it into
the smog chamber. Fig. 1(c) demonstrates a good enhancement of a broad peak from 230 nm
to 280 nm that corresponds to water insoluble portion of the diesel fume. The relative increase
of the water insoluble fraction from Fig. (b) to (c) proves a deduction of water soluble fraction
in the diesel fumes. This could in turn have a positive effect on the atmospheric pollution.