ABSTRACT
This chapter begins with describing and quantifying the physical and chemical phenomena controlling the exchange of chemicals between the atmosphere and water bodies such as oceans, lakes, and rivers. It describes the several physical processes which may apply simultaneously as a chemical migrates between the phases. Based on this conceptual "model", equations can be written describing the various processes and manipulated into convenient forms for applying to real situations in which the aim is to predict transfer rates. These equations contain equilibrium and kinetic parameters or coefficients which normally require separate determination. In some cases the coefficients can be estimated indirectly or obtained from correlations. A complete predictive procedure thus emerges which may be applied to any given air-water exchange situation. The chapter evaluates the simplest "two-resistance" volatilization model in concentration terms, then independently the simple atmospheric deposition models. Although there is confidence that the model is reliable there remain situations in which experimental verification of the predictions is desirable.
