How to Remove Permanent Hardness of Water

Hard water is a state of water with dissolved calcium and magnesium. There are two types of hard water. The hardness of water caused by calcium bicarbonate is known as temporary hardness. This dissolving of minerals takes place during normal water cycles, and the grade of hardness sometimes depends on the geological area. Residues in the dishwasher, less foam with detergents and soap, wearing out of clothes, and less water pressure through taps are some of the common signs to take an appointment for the softening of water in your home. 

There are no serious health issues regarding hard water, but it might cause dry skin and hair. Temporary hardness can be removed by boiling, but permanent hardness cannot be removed with this method. Water softening at home can be done using a resin coated with sodium. Other methods of removing hardness include Clark’s process, Calgon’s process, and ion-exchange resin.

What is Hard Water?

A state of water incorporated with calcium and magnesium is known as hard water. When hard water is boiled in boilers, calcium carbonate crystals accumulate as plaques, reducing the equipment’s lifespan dramatically. This mineral breakdown occurs naturally during water cycles. The extent of hardness varies depending on the geological location.

How Can You Detect the Hardness of Water?

Hard water may not seem very visible. But when we closely observe, we can feel the hardness of water. Here are a few ways to detect it:

• Stains in sink and tub
• Clothes wear out easily
• Dull colours of clothes
• White, chalky residue on dishes and pipes
• Dry skin and dry hair
• Hard water will not form lather with soap.

Hard Water Problems

We’ve discussed the signs of hardness. Let’s now discuss the problems of having hard water. We don’t want our daily use of water to make us feel bad, right? When you have hard water, sulphur present in it might cause a rotten egg smell. It will have a musty odour and taste. Hard water will also have a metallic smell and taste. It causes discoloration and cloudiness. Additionally, the rusting of iron and steel is enhanced with hard water. In industrial cases, hard water causes corrosion, deterioration of equipment, build ups in pipes, and low flow pressure.

How to Remove Permanent Hardness of Water

Hard water can be permanent or temporary. Permanent hardness is the most difficult to deal with. This is the result of mineral sulphates and chlorates.

Boiling

Bicarbonates in temporary hard water are precipitated into insoluble form during heating. This insoluble form later separates out.

Ion Exchange

Hard water is passed through zeolite or resin containing columns. These columns will have sodium ions in it. When hard water passes through the column, it binds to the less tolerable ions in hard water. In return, sodium ions are released from column to hard water as a counter action. These sodium ions are more tolerable.

Chelation

Chelating agents like ethylenediaminetetraacetic acid (EDTA) bind to the non tolerable ions in hard water.

Reverse Osmosis

In this method, there is an impermeable membrane only permeable to water. Hard water is passed through this filter with high pressure, leaving large particles causing hardness behind.

Lime Softening

Calcium hydroxide (slaked lime) is added to hard water. It increases the Ph of hard water leaving precipitates of CaCO3 and Mg(OH)2.

This insoluble precipitate is later removed. After that an acid was added to water to bring its Ph back to normal.

Questions on Removing the Permanent Hardness of Water

What is permanent hard water?

Hard water is formed due to dissolved minerals. It is the water with high mineral count.

What are the types of hardness?

Hardness of water can be temporary and permanent. Hardness is caused by carbonates and bicarbonate of calcium and magnesium. Permanent hardness is caused by other salts of calcium and magnesium.

What are the methods to remove hardness of water?

• Boiling
• Clark’s process

Ca(HCO3​)2​ + Ca(OH)2​ → 2CaCO3 ​+ 2H2​O.

• Calgon’s method

Calgon reacts with hard water and precipitates with salts, which is easier to remove from water.

• Using ion exchange resins 

The unwanted ions in hard water are exchanged with more agreeable ions like sodium ions.

• Using washing soda

What is reverse osmosis in removing hardness?

In this method, there is an impermeable membrane only permeable to water. Hard water is passed through this filter with high pressure, leaving large particles causing hardness behind.

What is lime softening?

Calcium hydroxide (slaked lime) is added to hard water. It increases the pH of hard water, leaving precipitates of CaCO3 and Mg(OH)2.

This insoluble precipitate is later removed. After that, an acid is added to water to bring its pH back to normal.

Conclusion

Hard water can be permanent or temporary. Permanent hardness is the most difficult to deal with. This is the result of mineral sulphates and chlorates. Hardness causes residues in the dishwasher, less foam with detergents and soap, wearing out of clothes, and less water pressure through taps. If you see any of these common signs, make sure to take an appointment for softening of water at home. 

There are no serious health issues regarding hard water, but it might cause dry skin and hair. Temporary hardness can be removed by boiling, but permanent hardness can’t. Water softening at home can be done using a resin coated with sodium. Other methods of removing hardness include Clark’s process, Calgon’s process, and ion-exchange resin.