Modules for the conversion of sulfate has been included in the urban scale K-theory particulate model, AROSOL. Two modules are included: one is an empirical first order SO2 conversion scheme termed EMM and the other is a series of chemical kinetic reactions based on the Carbon Bond Mechanism, termed CBM-IV. These modules can interact with two modules for the aerosol phase. One, the aerosol dynamics model (ADM), includes modules for the treatment of binary nucleation of the sulfuric acid-water system and condensation on existing particles. The other is termed the lumped aerosol model (LAM) and treats sulfate as another separate component in the atmosphere. The use of LAM and ADM with AROSOL is discussed. The use of EMM and LAM in AROSOL is illustrated with test simulations using 1982 Philadelphia Aerosol Field Study data.