The study on the evaporation behaviors of diesel oil contaminants

The evaporation of diesel oil, 90# gasoline and aromatic mixture on free surface of petri dishes were carried out at the ambient temperature of 20°C. The results showed that there were different evaporation behaviors for different oil products. Diesel oil evaporates in a power manner, where the loss of mass is approximately power with time, and has the fit equation of y = 0.0062 t
^0.7612
. While 90# gasoline evaporates in a logarithmic with time and with the fit equation of y = 15.803 ln (t) − 20.884. The aromatic mixture evaporates as linear with time and with fit equation of y = 0.0321 t + 3.6739. The evaporation of diesel oil leads to the changes of diesel physical properties, it lead the increase of the viscosity and the decrease of API gravity (American Petroleum Institute gravity). And there is positive relativity between viscosity of residual diesel oil and the loss percent of diesel oil during evaporation process. During the diesel oil evaporation, the compositions of those less than 15 carbon atoms has affected, mainly those less than 13 carbon atoms compositions. And the results presented that the evaporation behavior of different composition of diesel oil varied with different composition. The influences of soil type and air porosity on evaporation behavior of diesel oil in unsaturated soil were studied in this paper. During the diesel oil evaporation in thin layer soils (5 mm thick), the soil type was the dominant factor; while during volatilization in soil columns (200 mm thick), the air porosity was the dominant factor.