Hard water is a common nuisance for households and industries, causing mineral buildup on plumbing fixtures, sanitary fittings, utensils, water boiler systems and pipework. In addition, it inhibits soap/detergent performance besides causing skin and hair problems. Here we have given some ways to deal with it.
Water softening is one of the most efficient ways of treating hard water. It aims at reducing the concentration of calcium, magnesium and other hardness causing mineral cations. Different methods are employed for water softening.
Conventional water softening devices use an ion-exchange resin which bind the hardness ions(mainly calcium and magnesium ions) to a molecule. This refrains them from forming scales or interfering with detergents. The hard water passes thru a bed of resin with charged sodium attached to its surface. The resin binds calcium and magnesium ions and releases sodium into the water. Resins for removal of bi-carbonate, carbonate and sulphate ions are also available.
Lime Softening is another effective method which utilizes lime or calcium hydroxide to remove calcium and magnesium ions(hardening agents) by precipitation. Lime(Calcium hydroxide) reacts with the calcium and magnesium to form calcium carbonate and magnesium hydroxide which precipitate in sludge form. This causes considerable reduction in TDS (total dissolved solids) as compared to the ion exchange method. It also eliminates microorganisms and other dissolved organic matter. This method can be used to expel impurities like iron, manganese, arsenic and radium from water.
Chelants are used as chemical water softeners in shampoos, laundry detergents and other hard surface cleaning agents specially meant for performing well in hard water. The most commonly used chelant is EDTA (ethylenediamine tetraacetic acid). Chelants bind with minerals found in hard water and prevent them from forming a residue, resulting in sparkling clean clothes and surfaces.
Water conditioning is done by subjecting hard water to a strong focused magnetic field in a set up that causes electron excitation to occur. This in turn ensures that calcium crystals and other mineral mineral deposits precipitate out in a low density form and remain suspended in water rather than stick to the inner surfaces of pipes and other surfaces. This precipitated matter, also called soft scale is much easier to remove than a rock like hard layer of limescale.
Distilling hard water is often done for industrial uses like automotive cooling systems and boiler systems. The presence of other ions commonly found in hard water affect the lifespan of automobile batteries. So only distilled water is used to refill lead acid batteries used in cars and trucks. In this process, impure water is converted into steam by boiling. The impurities are left behind in the boiling chamber. The steam passes into a cooling section and condenses back into water in a purer form. This condensed water then flows into a storage container. Distillation process removes almost all of the mineral contaminants from hard water.
Reverse Osmosis (RO) has emerged as the most effective technology for desalination and water softening, both for domestic and industrial uses. In Reverse Osmosis systems, hard water is forced under pressure against a semi-permeable membrane made of thin film composite poly-amide. The membrane remove impurities and mineral particles larger than .001 microns and allows only pure water molecules to flow through. The retained impurities and dissolved salts are drained out as waste water. Reverse Osmosis systems remove excess TDS(totally dissolved solids) from water. Also, the pre-filters and activated carbon in such systems make water absolutely safe for drinking. Reverse Osmosis is completely non-toxic as no chemicals are added to the water.
Temporary quick fixes
There are many quick fixes for softening water that you can try at home. The results do not last long, but these methods are quite effective in removing the mineral build up and making hard water soft to a certain extent.
One solution for softening hard water is to boil it after filtering. The lime settles down to the bottom and you can use this water for cooking and drinking. However, do note that this does not eliminate mineral impurities from the water completely.
Soap sud formation is affected considerably by the minerals present in hard water. Adding borax or washing soda at the time of washing clothes, gets rid of this problem and improves soap/detergent performance in hard water.