The Almighty has blessed us with pure & clean water in form of
- ponds and
The Almighty stores the water in glaciers and clouds.
But, we have contaminated our streams, ponds and lakes by adding impurities. Moreover, the water we extract from earth also contains many contaminants.
Humans impure water either by adding industrial waste or by adding any other form of impurities.
To get clean water for the purpose of drinking, we adopt several methods, reverse osmosis is among those methods.
What's in this article...
How RO plant works?
The questions which arise in everybody’s minds are what is RO or reverse osmosis, and how does a reverse osmosis plant works?
What is Reverse Osmosis?
The internet encyclopedia, Wikipedia, defines reverse osmosis as:
“Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules and larger particles from drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property that is driven by chemical protential differences of the solvent, a thermodynamic parameter. Reverse osmosis can remove many types of dissolved and suspended species from water, including bacteria, and is used in both industrial processes and the production of potable water.”
الٹادلوج منحل کو محلول سے الگ کرنے کا طریقہ اس میں محلول کو ایک جھلی میں سے معمولی کے دلوجی درجہ حرارت سے زیادہ درجہ حرارت پر بہنے دیا جاتا ہے ۔ اسے غذائی مصنوعات کے ارتکاز یا خشک کرنے کے لیے زیر عمل لایا جاتا ہے ۔ (خصوصاً دودھ اور جوسز کے لیے ) کیمیکل پلانٹس میں ری سائیکل واٹر کے ٹریٹمنٹ کے لیے استعمال ہوتا ہے ۔
Some important definitions:
Before we explain the process, go through these terms to fully understand the
The desalinated water that is demineralized or deionized.
The water stream that conveys the concentrated contaminants that did not go through the RO membrane.
The water that endures the RO membrane is called permeate or
The Reverse Osmosis Process:
Reverse Osmosis works by utilizing a high pressure pump to expand the pressure on the salt side of the RO
then allow the water across the semi-permeable RO membrane.
Eventually it leaves all of disintegrated salts behind in the reject stream.
The measure of pressure required relies upon the salt grouping of the feed water.
The more concentrated the feed water, the more pressure is required to beat the osmotic pressure.
As the feed water enters the RO membrane under pressure (greater enough to overcome osmotic pressure) the water particles go through
- the semi-permeable membrane and
- the salts
and different contaminants are not allowed to pass and are released through the rejected stream.
We drain this steam. in a few conditions, We can also fed back into the feed water supply to be reused to save water.
The product water, for the most part has around 95% to 99% of the removed dissolved salts.
The RO framework utilizes cross filtration as opposed to standard filtration where the contaminants are gathered within the filter media.
With cross filtration, the solution goes through the channel, or crosses the filter, with two outlets: the sifted water goes one way and the polluted water goes another way.
To maintain avoidance from develop of contaminants, cross flow filtration allows water to clear away contaminants. It also allows enough turbulance to keep the membrane surface clean.
The contaminants Reverse Osmosis removes:
Reverse Osmosis is exceptionally powerful in treating
- ground and
- salty water
for both vast and little flows applications.
Reverse Osmosis can expel up to 99%+ of the dissolved salts (particles),
- bacteria and
from the feed water.
Criteria of removal:
An RO membrane rejects contaminants dependent on their size and charge.
Any contaminant that has a molecular weight more noteworthy than 200 is likely rejected by a legitimately running RO plant (Note here that a water atom has an MW of 18).
In like manner, the more prominent the ionic charge of the contaminant, the more probable it will note be able to go through the RO membrane. For instance, a sodium particle has just a single charge (monovalent) and isn’t removed by the RO membrane and additionally calcium for instance, which has two charges.
Limitations of an RO plant:
An RO framework does not expel gases, for example, CO2.
As RO water plant does not expel gases, the permeate water can have a somewhat lower than ordinary pH level contingent upon CO2 levels in the feed water as the CO2 is changed over to carbonic corrosive.