ABSTRACT
Most significant chemical and biochemical phenomena in water involve interactions between species in water and another phase as discussed in this chapter and illustrated in Figure 4.1, including the following: Sediment can be washed physically into a body of water. Production of solid biomass through the photosynthetic activity of algae occurs within a suspended algal cell and involves exchange of dissolved solids and gases between the surrounding water and the cell. Similar exchanges occur when bacteria degrade organic matter (often in the form of small particles) in water. Chemical reactions that produce solids or gases in water occur. Iron and many important trace-level elements are transported through aquatic systems as colloidal chemical compounds or are sorbed to solid particles. Pollutant hydrocarbons and some pesticides may be present as immiscible liquid films on the water surface.
