The effect of the fractal dimensionality on sedimentation with either open or closed boundary conditions is determined for polydisperse systems. The differing roles of the particle size on diffusion and migration in a field can be seen. Coagulation of an aerosol is modeled by integration of the master equations for two different values of the fractal dimensionality. Little effect is seen here although there is a more pronounced effect on the rates of scavenging of a smaller particle by growing aerosols of different fractal dimensionalities. Finally, the role of the fractal dimensionality in the interaction of charged particles is found to be negligible for oppositely charged particles but is significant for particles of the same charge.