Investigation of partitioning mechanism for volatile organic compounds in a multiphase system

Laboratory experiments were performed to investigate the partitioning behavior of a set of diverse volatile organic compounds (VOCs). After equilibration at a temperature of 25 °C, the VOC concentrations were measured by headspace method in combination with gas chromatography/mass spectrometry (GC/MS). The obtained data were used to determine the partition coefficients (KP) of VOCs in a gas–liguid–solid system. The results have shown that the presence and nature of solid materials in the working solution control the air–water partitioning of dissolved VOCs. The air/solution partitioning of BTEX and C9–C10 aldehydes was most affected in the presence of diesel soot. KP values decreased by a factor ranging from 1.5 for toluene to 3.0 for ethylbenzene. The addition of mineral dust in the working solution exhibited greater influence on the partitioning of short aldehydes. KP values decreased by a factor of 1.8. The experimental partition coefficients were used to develop a predictive model for partitioning of BTEX and n-aldehydes between air, water and solid phases.

Research highlights
► We investigate the partitioning behavior of BTEX and n-aldehydes in a multiphase system.
► The partition coefficients are experimentally determined at temperature of 25 °C. Coefficient values depend on presence of solid materials in the system.
► We model a partitioning mechanism of VOCs between air, water and solid phases.