The objective of the present research project is to develop a one dimensional Lagrangian aerosol code based on the solution of the General Dynamic Equation of aerosols. We will investigate the importance of different background aerosol concentrations on the growth and transport of sulfur particles in typical conditions of condinental air and compared with available experimental data, where the size distribution of sulfur and ammonium ions were measured. Furthermore, the importance of different physical mechanisms (e.g. nucleation, condensation, coagulation, settling) on the evolution of the aerosol size distribution will be examined. The development of the aerosol code will be based on the research made in the Safety Technology Institute, Italy for the development of a one dimensional Lagrangian code for aerosol transport. The General Dynamic Equation f aerosols will be solved numerically using a discrete-nodal point method to describe the particle size distribution. Different mechanisms will be included in the model as binary nucleation and condensation, chemical reactions and settling.