Abstract
Seawater is composed of a number of different components that can be divided into the
following phases:
1. Solids (material that does not pass through a 0.45-μm flter)
a. Particulate organic material (plant detritus)
b. Particulate inorganic material (minerals)
2. Gases
a. Conservative (N2, Ar, Xe)
b. Nonconservative (O2 and CO2)
3. Colloids (passes through a 0.45-μm flter but is not dissolved)
a. Organic (complex sugars)
b. Inorganic (iron hydroxides)
4. Dissolved solutes
a. Inorganic solutes
1. Major (>1 ppm)
2.Minor (<1 ppm)
b. Organic solutes
It should be pointed out that the separation of the phase of an element between solid,
colloidal, and dissolved is operational and dependent upon the separation method used.
Figure 2.1 demonstrates how the sizes of some solutes are related to the methods used to
separate the phases. This chapter discusses the various dissolved major components of
seawater. It examines the concentration of the major components in seawater and the processes that can cause them to vary from place to place.