WHAT IS REVERSE OSMOSIS
Reverse Osmosis is a membrane process that
acts as a molecular filter to remove over 99% of all dissolved
minerals. Water passes through the membrane while the dissolved
and particulate matter is left behind.
As pressure is applied to the concentrated
solution, the flow is reversed and water is passed through
the membrane from the concentrated side to the dilute side.
Water molecules penetrate the thin layer
of the membrane and diffuse through it molecule by molecule.
Dissolved salt ions would also diffuse through this layer,
except that the solubility of the salt ions in the feed is
much less than that of the water. This results in water passing
through the membrane more rapidly than salts, causing separation.
The driving force of the reverse osmosis
process is driven by both the feed water pressure and the
concentration differentials across the membrane surface. For
water, the pressure effect is the most important, and for
the dissolved ions in the water, the concentration difference
is the most important. Therefore, increases in pressure increase
the amount of treated water without causing a corresponding
increase in waste flow.
The RO process removes most of the dissolved
mineral salts, almost all of the particulate matter and most
of the dissolved organic compounds.