Modeling sorption transport in rooms and sorption filtration systems for building air quality analysis.

Adsorption, desorption and chemisorption are known to impact the dispersal of volatile organic and chemically reactive compounds in buildings. These same three processes may be used to advantage to control the levels of these compounds indoors using building sorption filtration devices. To add to the understanding of these processes, to provide the means to predict the impact of these processes on human exposure and to provide the tools needed to design gaseous filtration systems to mitigate the exposure to these compounds, a general approach to modeling the dynamics of these processes is presented. Equations are presented to account for the elemental advection, diffusion, sorption, and chemical transport steps affecting single component sorption dynamics in rooms and sorption filtration systems. These element equations are based on general principles and formulated in terms of fundamental physical parameters that may be determined using standard procedures. Models to predict room and sorption filtration system dynamics are formulated using assemblages of these element equations and a series of simplified models of these systems are derived. Initial applications to model single-component sorption transport in rooms and sorption filtration systems indicate that the approach has the potential to provide accurate predictions providing the sorption and chemical characteristics of the sorbatesorbent system being considered are well-characterized. This potential is, however, compromised by the lack (or present uncertainty) of fundamental data relating to sorption equilibrium, porous diffusion, surface chemistry, and boundary layer mass transport.