Bubble columns bounded dispersions

We are often concerned with the dispersion of pollutants and other chemicals in the environment. Advection and mass flux are indiscriminate transport processes. In the water column of a lake, for example, these processes transport dissolved and particle-bound chemicals equally across the boundaries of the test volume. Settling of particles, in contrast, causes a downward flux of particle-bound chemicals while leaving dissolved chemicals in place. Similarly, surfactants or gases that join rising air bubbles are carried to the surface. These discriminate transport processes are very important in a variety of environmental situations ... 

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