Influence upon Effusion of Hydrophobic Organic Compounds (HOCs) from Fog Droplets: Surfactant, pH, and Salt Effects

In this study, a HOCs-effusion reactor was constructed to investigate the effects of surfactant, pH, and salt concentration on the effusion of n-octane that we chose as a surrogate for hydrophobic organic compounds (HOCs) in fog droplets. Sodium dodecyl sulfate (SDS) was selected as the surfactant for our experiments. In addition, a correction factor a for the exchange constant of mass transfer of n-octane was defined and used to illustrate the effects mentioned above. The experimental results show that the values of a are in the range of 0.421-i).798 for the effect of SDS_ Thus, SDS can decrease the mass transfer of n-octane effused from the fog droplet by about 20-{)O%. However, the values of a vary from 1.17 to 1.57 and 1.42 to 4.23 for the effects of the H2S04 and NaCI. Therefore, ionic strength contributed by H2S04 and NaCI can increase the effusion rate of n-octane by about 17 to 57% for the effect of H2S04 and 42 to 323% for the effect of NaCI.