The million-dollar question is how to filter water for drinking & make it trustworthy.
Water is available everywhere on our planet in abundance.
The water filtration process is altogether different for different sources. There can be a massive difference in seawater & freshwater filtration costs.
It can be due to
- The difference in geographical locations.
- The requirement of additional filter components
- Rapidly increasing technology costs.
Water filtration in countries like Kuwait, Saudi Arabia, the USA, Australia, England differs a lot due to their geographical locations.
Sea & desert surrounds Saudi Arabia & Kuwait. They are devoid of any rivers & lakes. The use of the desalination process makes water fit for drinking. Due to abundant solar energy, solar water heaters are used in the desert for water desalination.
USA, England, Australia have freshwater resources like rivers & springs. So, the use of water resources is as per the drinking water demand. Densely Populated coastal regions have established desalination plants to cope up with heavy water demand.
In countries like Greenland & Antarctica, thick ice sheets trap freshwater. It is utilized to produce fresh water through different technologies.
What are the water purification methods?
There is a water purification solution for every type of water like sea water, fresh water.
98% of available water resource on earth is seawater & the rest is fresh water. There is gradual depletion in underground water. The steep rise in water pollution levels has posed a significant challenge in producing clean water.
Considering the ever exploding human population, one cannot think of survival without water.
So, here comes the brain tickling question again!
How to purify water through filtration for the exploding population?
Each water filtration process depends on its environment & surroundings to reach its full potential.
Water Desalination Process
One way of purifying seawater is to set up water desalination plants. Desalination plants take 2-3 years to assemble & cost millions of dollars. So, this process is costly & takes a tad bit of time to set up.
Certain places in the world have started installing desalination plants. These plants have the efficiency to convert 40% of seawater into freshwater.
Seawater TDS level has to bring on par with normal TDS level of freshwater. So, the reverse osmosis process expels the excess salts.
Water treatment is essential at this stage. As the reverse osmosis process ensures 45% of seawater conversion into pure water. Rest 55% of rejected water returns to the ocean as brine.
In final stages, Calcium & Magnesium is mixed to increase water minerals lost during the RO process.
At the final stage, we get filter water for drinking.
Reverse osmosis makes use of semi-permeable membranes of thickness 0.0001 microns. It is made up of 3 layers of materials: Polyamide, Polysulfone & Polyester base.
Polyamide layer is the topmost layer of a membrane sheet that is used to filter & refine unwanted chemicals, minerals & micro-organisms supported by thick Polysulfone layer & Polyester base.
The layered membrane sheet is wrapped around a cylindrical pipe & sealed at both end. Only raw water in & filtred water out connections are available.
Reverse osmosis process in desalination
Lets learn how reverse osmosis works!
Reverse osmosis membranes are very delicate. Any bigger water particle can damage the semi-permeable membranes permanently. All impurities have to be removed & raw water has to be purified before undergoing the reverse osmosis process.
Sea Water has to pass through screening. Multiple filtration stages are used to remove sand, mud, unwanted water particles & turbidity.
Then it has to undergo a sedimentation process by passing through sand granules filter followed by an activated carbon filter.
This filtration stage will remove all the unnecessary water elements like foul odor, pesticide, micro-plastics & chlorine.
To improve output water efficiency multiple stacks of ro membrane cylindrical pipes are used at various stages of the ro process.
Water pressure decreases at the end of each ro stage. So, a medium hp motor is used at each of these stages. This ensures that the water is pushed to subsequent stages for filtration. The process is repeated until the ro water is not filtrable anymore.
Thermal Process for desalination
Thermal power plants use the thermal process for desalination. Herein, boilers are used to remove impurities by evaporating water & condensing them again.
Thermal power plants do not need reverse osmosis process as all water impurities are removed at the condensation stage.
Low Temperature Thermal Desalination Plants ( LTTD )
LTTD plants are designed on the fact that water evaporates at lower temperatures at lower pressure. Vacuum pumps play an important role in creating low temperatures & low-pressure environments in which water evaporates at a temperature gradient of 8-degree Celcius between two volumes of water.
LTTD plants are environment friendly. Water wastage in LTTD is extremely less in comparison to reverse osmosis plants.
In a nutshell, warm water is pumped to a giant flash chamber. Generated water vapor is condensed. Then fresh filter water for drinking is pumped out!
LTTD technology is promising as the cost is extremely less in comparison to RO technology. This is extensively used in small islands for generating fresh water.
What is a water filtration machine?
A water filtration machine is of two different types. The first one is a fully electric operated RO+UV+MF water purifier. Second is the gravity-based water purifier.
Electric water filtration machines
are made up of a combination of different technologies like reverse osmosis, UV lamp, Ultrafiltration(UF) membrane & carbon filter.
The machines make use of sedimentation filters to filter sand, mud, etc. These big water particles can damage reverse osmosis membranes severely.
Thereafter raw water has to undergo filtration process through a carbon filter to remove odor, chlorine & pesticides.
Carbonated water passes through the reverse osmosis stage. Water salts & micro-organisms bigger than 0.0001 microns are unable to pass through it. The expelled water is drained as wastewater.
Now 99% of RO purified water may still contain microorganisms. So, UV lamp radiation is used to destroy them.
Finally RO water is ready for storage in tank for drinking purpose.
Drinking water filter
Gravity based water purifiers are non-electric drinking water filter.
They use simple sediment filter & activated carbon filter to purify water. They can’t filter disease-causing microorganisms & treat hard water into soft water.
Filter water for drinking
We are the one to make choices about the quality of water that we want to drink. The finest water quality needs more money as technology makes it costly.
That water is RO water which is the most safest & healthiest.
We have seen a number of water purification technologies at work all over the world. Purified water as a resource is still scarce.
Its existence is constantly threatened by heavy pollution & human activities.
Advanced water purification technologies like RO & UV are still very costly. Not everybody can own them. We must learn to respect water & stop polluting it. It comes at a huge cost. Days are not far when we would be paying price for wasting every drop of water.
Its better to rise up early & correct our mistakes.