ABSTRACT
This chapter aims to include advection and reaction rates in evaluative calculations involving equilibrated compartments under the steady-state assumption. The great advantage of working with fugacity becomes apparent when considering how to express the equilibrium environment mathematically. Translation and extrapolation of reaction rates from environment to environment and laboratory to environment is therefore a challenging and fascinating task that will undoubtedly keep environmental chemists busy for many more decades. In reality, virtually all environmental reactions are second-order processes, i.e., the rate depends on the concentration of both the chemical and on a second term that is characteristic of the reactive nature of the environment. Confusion may arise when calculating the residence time or persistence of a chemical in a system in which advection and reaction occur simultaneously. Local efforts to reduce contamination by controlling local sources may therefore be frustrated, because most of the chemical is inadvertently imported.
