Water filtration

Activated Carbon Filtration
Sand,D.E,Cartridges filters
Softening: P.H balance.
Identification and Correction
Chlorination
Reverse osmosis

Reverse osmosis occurs when the water is moved across the membrane against
the concentration gradient, from lower concentration to higher
concentration. To illustrate, imagine a semipermeable membrane with fresh
water on one side and a concentrated aqueous solution on the other side.
If normal osmosis takes place, the fresh water will cross the membrane to
dilute the concentrated solution. In reverse osmosis, pressure is exerted
on the side with the concentrated solution to force the water molecules
across the membrane to the fresh water side.

Reverse osmosis is often used in commercial and residential water
filtration. It is also one of the methods used to desalinate seawater.
Sometimes reverse osmosis is used to purify liquids in which water is an
undesirable impurity

How reverse osmosis works

Reverse osmosis is sometimes referred to as ultrafiltration because it
involves the movement of water through a membrane as shown in Figure 1.
The membrane has microscopic openings that allow water molecules, but not
larger compounds, to pass through. Some RO membranes also have an
electrical charge that helps in rejecting some chemicals at the membrane
surface. Proper maintenance is essential to retain effectiveness over
time. Some units are equipped with automatic membrane flushing systems to
clean the membrane.
What impurities will reverse osmosis remove?

Reverse osmosis (RO) has become a common method for the treatment of
household drinking water supplies. Effectiveness of RO units depends on
initial levels of contamination and water pressure. RO treatment may be
used to reduce the levels of:
Naturally occurring substances that cause water supplies to be unhealthy
or unappealing (foul tastes, smells or colors).
Substances that have contaminated the water supply resulting in possible
adverse health effects or decreased desirability.

RO systems are typically used to reduce the levels of total dissolved
solids and suspended matter. The principal uses of reverse osmosis in
Minnesota and the Dakotas are for the reduction of high levels of nitrate,
sulfate, sodium and total dissolved solids.

RO units with carbon filters may also reduce the level of some SOCs
(soluble organic compounds) like pesticides, dioxins and VOCs (volatile
organic compounds like chloroform and petrochemicals). An RO unit alone
may not be the best solution for these types of contaminants, but
installing a properly design-ed RO unit to reduce the levels of other
contaminants may provide a reduction in SOCs and VOCs.