10. Lipids in Water-Surface Microlayers and Foams
245
provide a standard method for sampling the surface microlayer (Greenberg et aI.,
1992).
10.5. Physicochemical Processes at the Surface Microlayers
The fate and distribution of materials in the surface micro layers and foam depend
on the material's physical and chemical properties (e.g., aqueous solubility,
diffusivity in air and water, viscosity, specific gravity, vapor pressure, and reactivity) and a series of environmental factors that influence their transport and
transformation (Fig. 10.3). The aqueous solubility of a substance depends on the
dielectric constant (E) of the solvent (i.e., on the polar characteristic of the water
molecules). Studies of the dielectric properties of water adsorbed on gels and
porous and nonporous substrates demonstrated that the dielectrict constant
changes in the range of 78.5-4.5 (at 25°C and I atm) for film thicknesses
wind action
dissolution
precipitation
complexation
adsorption
redox
Well-Mixed Water
upwelling
(particle
resuspensk;)n)
,
<
Well-Mixed Air
FIGURE 10.3. Physicochemical and biological processes related to the transport and alteration of materials occurring at the air-water interface of aquatic ecosystems.
245
provide a standard method for sampling the surface microlayer (Greenberg et aI.,
1992).
10.5. Physicochemical Processes at the Surface Microlayers
The fate and distribution of materials in the surface micro layers and foam depend
on the material's physical and chemical properties (e.g., aqueous solubility,
diffusivity in air and water, viscosity, specific gravity, vapor pressure, and reactivity) and a series of environmental factors that influence their transport and
transformation (Fig. 10.3). The aqueous solubility of a substance depends on the
dielectric constant (E) of the solvent (i.e., on the polar characteristic of the water
molecules). Studies of the dielectric properties of water adsorbed on gels and
porous and nonporous substrates demonstrated that the dielectrict constant
changes in the range of 78.5-4.5 (at 25°C and I atm) for film thicknesses
wind action
dissolution
precipitation
complexation
adsorption
redox
Well-Mixed Water
upwelling
(particle
resuspensk;)n)
,
<
Well-Mixed Air
FIGURE 10.3. Physicochemical and biological processes related to the transport and alteration of materials occurring at the air-water interface of aquatic ecosystems.