TDS is a common terminology in use whenever you discuss water purification.
What exactly is TDS?
Let us look at this concept in brief.
Water is the Best Health Drink in the world that contains no fat, no calories, and no cholesterol.
Health Authorities often check the following to make sure that the water is safe.
- Presence of Dissolved Oxygen
- Presence of the Bacterial Growth, Algae, algae
- Total Dissolved Solids (TDS)
Total Dissolved Solids
A water molecule in its purest form contains 2 atoms of Hydrogen and 1 atom of Oxygen.
But, the water available from natural sources like rivers, lakes, and groundwater does not conform to this molecular formula.
This is because water contains a lot of organic and inorganic salts dissolved in it.
This water contains calcium, magnesium, sodium, potassium, sulfates, carbonates, nitrates, and fluorides among many other salts.
This seems to be a very long list, but the positive aspect is that you need a majority of these salts for your overall growth.
You need a certain proportion of these solids in your drinking water.
However, water can contain other contaminants such as heavy metals like arsenic, lead, and even mercury. These chemicals are dangerous and require elimination.
TDS up to a certain level is acceptable for human consumption.
It is only when the TDS proportion exceeds 500 (500 ppm) does it become hazardous. You would require the use of water purifiers to eliminate the excess TDS.
The Hardness of the Drinking water is created by naturally occurring substances like calcium (Ca) and magnesium (Mg).
Total Dissolved Solids (TDS) are the total amount of the mobile charged ions in a given volume of water which include minerals, salts, cations, anions, and metals.
TDS = The Total number of cations and anions in the water.
Rain Water is the Purest form of water, and the TDS of rainwater is few tens of mg/L.
TDS is represented in units of mg per unit volume of the water ( mg/l ) that is also referred to as parts per million ( ppm ).
The Dissolved salts come from both natural and inorganic sources. The Organic sources of the dissolved salts include leaves, plankton, trash from industries, pesticides, fertilizers and more.
Water will also pick up metals like lead and copper when it travels through the pipelines.
The Dissolved salts also come from the artificial sources such as rocks, atmospheric gasses, nitrogen iron, and minerals also.
Over time, Water purifiers will lose the capability of removing the Dissolved salts from water.
You should observe the Quality of the membrane in your water filter and should replace it when required.
Please note that the presence of the Dissolved salts in water will affect the taste.
According to World Health Organization, TDS level less than 300 mg/litre is considered as excellent, between 300 and 600 mg/liter is good, 600-900 is fair, 900 – 1200 is poor and TDS level more than 1200 mg/liter is unacceptable.
In India, If the TDS level is above 500mg/liter, the water is considered as disagreeable. But, due to the lack of water resources, people are drinking water that has greater TDS Levels.
According to the BIS Standards, the maximum desirable TDS is 300 mg/l and maximum permissible is 600 mg/l.
WHO states that the water containing TDS concentrations below 900 mg/litre are acceptable for the consumers. Lesser the TDS, Better the Water
How to Reduce the TDS in Water?
There are a lot of RO water purifiers available that can reduce or remove the Dissolved salts in the water.
The most widely used Water Purifications Systems are Carbon filtration, Reverse Osmosis, Distillation, and Deionization.
In Carbon filtration, the Charcol consumes many toxic compounds when the water is passed through the activated charcoal.
Reverse Osmosis is one of the most commonly used filtration systems that removes all the dissolved contaminants in the water. The Only problem with RO is, It needs a lot of water.
The RO process splits the water into two parts and drives the dissolved salts out from the part into other.
As I mentioned above, Reverse osmosis requires a lot of water, and the wastage is also high.
If you input 3 Litres of Water into the RO Process, you will get one litre of Clean water and 2 liters of Dirty water.
So, when you are planning to buy a Ro Water Filter, Make sure you collect the Reject water and use it for cleaning the house. Don’t waste the Reject Water of Reverse Osmosis purification system.
Distillation involves boiling the water and produce the water vapor that rises to a cooler surface and condensed back to liquid. Distillation is one of the oldest forms of water purification which is still used to convert the sea water to drinking water.
In this process, the Dissolved salts in the water are removed through the ion exchange. By Controlling the electric charge of the ions in the water, the Deionization removes the TDS from the water.