Hard water poses critical problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers and other equipment that handles water. In domestic settings, hard water is often indicated by a lack of foam formation when soap is agitated in water, and by the formation of limescale in kettles and water heaters.[1]Wherever water hardness is a concern, water softening is commonly used to reduce hard water’s adverse effects.
With hard water, soap solutions form a white precipitate (soap scum) instead of producing lather, because the 2+ ions destroy the surfactant properties of the soap by forming a solid precipitate (the soap scum). A major component of such scum is calcium stearate, which arises from sodium stearate, the main component of soap:
2 C17H35COO− (aq) + Ca2+ (aq) → (C17H35COO)2Ca (s)
Hard water also forms deposits that clog plumbing. These deposits, called “scale”, are composed mainly of calcium carbonate (CaCO3), magnesium hydroxide (Mg(OH)2), and calcium sulphate (CaSO4).Calcium and magnesium carbonates tend to be deposited as off-white solids on the inside surfaces of pipes and heat exchangers. This precipitation (formation of an insoluble solid) is principally caused by thermal decomposition of bicarbonate ions but also happens in cases where the carbonate ion is at saturation concentration. The resulting build-up of scale restricts the flow of water in pipes. In boilers, the deposits impair the flow of heat into water, reducing the heating efficiency and allowing the metal boiler components to overheat. In a pressurized system, this overheating can lead to failure of the boiler. Benbell Softener Systems provide the widest range of Industrial softeners and Commercial softeners which are fully customised to deliver soft water as per required standards.
Hard water causes wastage of soap. Precipitate of magnesium and calcium soaps adhere to the fabrics and cause problems.
Water containing nitrates, sulphates and alkali carbonates causes difficulty in crystallization of sugar. Moreover the sugar so produced may be de-liquescent.
The dissolved salts in water react with costly dyes causing precipitates.
Calcium, magnesium and iron salts dissolved in water severely effect the quality of paper
Hard water develops undesirable products while preparation of pharmaceutical products
Water containing chlorides and sulphates if used for concrete making effects the hydration of cement and the final strength of the hardened concrete.
Hard water used in laundry causes much of the soap used in washing to go as waste and even cause discolouration of clothes
For steam generation boilers are invariably employed. If hard water is directly fed to the boilers a number of troubles arise such as scale and sludge formation , corrosion, priming and foaming and caustic embrittlement of the boiler.
