Water with a high dissolved mineral content is referred to as hard water, as opposed to soft water having a low dissolved mineral content. Calcium (Ca2+) and magnesium (Mg2+) ions are abundant in hard water. Water hardness is defined as the concentration of multivalent cations. Multivalent cations are metal ions with a charge greater than 1+, most commonly 2+.

These ions enter water supplies via leaching from aquifer minerals, such as limestone.The two common calcium-containing minerals are Calcite and gypsum.

But, do you know the solution of hard water?

Yes, it is water softening!

Where do we find hard water?

Hard water is typically found in groundwater (wells) because the water is in direct contact with minerals, which can be dissolved. Surface water (lakes, rivers, and streams) is generally soft with very low levels of hardness.

Hard water is generally not harmful to one's health, but it can cause serious plumbing issues in both residential and commercial applications. Water hardness is a serious issue, causing everything from a lack of suds formation in bathing and laundry applications, to costly breakdowns in boilers, cooling towers, and other water-handling equipment.

The dissolution/formation of calcium carbonate scales is described by the following equilibrium reaction:

CaCO₃ + CO₂ + H₂O = Ca²⁺ + 2HCO₃^-

Thus, the ion exchange process is effective at removing calcium and magnesium ions.

What is water softening?

Water softening is a process that addresses the issue of "hard water." Hard water is defined as water that contains more minerals than regular tap water. It's mostly due to high calcium and magnesium levels, which makes it difficult for products like soap to dissolve in water. It can also cause hard water stains in bathtubs and sinks, as well as clogged pipes.

Basic methods for water softening

· Washing soda method

Water is treated with a calculated amount of washing soda (Na₂CO₃), which converts calcium and magnesium chlorides and sulphates into their respective carbonates, which precipitate.

   CaCl₂ + Na₂CO₃ --> CaCO₃ + 2NaCl

  MgSO₄ + Na₂CO₃ --> MgCO₃ + Na₂SO₄

· Ion-exchange resin method

Ion-exchange resins are organic polymers with anionic functional groups that bind divalent cations (Ca²⁺), stronger than monovalent cations (Na+). Ion-exchange properties are also found in inorganic materials known as zeolites.

These minerals are common in laundry detergents. Resins are also available to eliminate the absorbed carbonate, bicarbonate, and sulfate ions, as well as the hydroxide ions released by the resin.

Manufacturer of water softeners

If you have any questions about water treatment plants, or if you would like to discuss about water softeners, please contact the Netsol Water team right away. Our team is an expert in water treatment and can help you tailor a solution, to your specific requirements.