Mechanical filtration.
Mechanical filtration removes
suspended solids, plankton and bacteria and is usually
used with the other forms of treatment described below.
The type of mechanical filtration used depends on the
condition of the incoming water and the volume of water
to be treated. A mechanical filter usually consists of a
series of filters that remove in
-
creasingly smaller particles—sand
filters or polyester filter bags (20-
to 35-μm), followed by cartridge
filters (10-, 5-, 1-μm) or diatoma
-
ceous earth (DE) filters. Small
volumes of seawater can be filtered
to remove bacteria using 0.22- or
0.45-μm membrane cartridge
filters.
Chemical filtration.
Dissolved
inorganic and organic compounds
(DOC), metals, pesticides, and
other contaminants can prevent
or retard microalgal growth, al
n
commercial hatcheries