Ultrafiltration is a
low-pressure membrane process used to separate bacteria,
viruses, and high molecular weight compounds colloidal and
particulate matters from a feed stream.
Ultrafiltration has larger
pores and high permeability with less osmotic effects that
allows ultrafiltration to operate at relatively lower pressure
than nanofiltration and reverse osmosis and is therefore it is
least costly to operate.
Ultrafiltration is widely
used in industry as pretreatment for other forms of
purification such as ion exchange and reverse osmosis, gelatin
and protein concentration in the pharmaceutical industry, sugar
clarification in the food and beverage industry, cheese and
whey concentration, production of ultra pure water,
clarification of juice, downstream processing, membrane
bioreactors, treatment of bleach plant effluents, and recovery
of lignin compounds in the pulp and paper industry.
Ultrafiltration can be used to reject virus, bacteria,
pyrogens, endotoxins, and particulates but not ionic species.
Hollow fiber configuration
is widely used in the ultrafiltration processes. The benefit of
this construction is that it allows for backwashing of the
membrane when the filtrate or product flow rate has decreased
due to accumulation of material on the membrane. The
ultrafiltration membrane is capable of removing colloidal
materials, fine suspensions, bacteria, virus, suspended
material and large dissolved molecular weight organic
materials.