Hardness generally refers to the sum of the calcium and magnesium ions in water expressed in milligram/liter of lime stone, CaCO3. These ions combine with ordinary soaps to form insoluble calcium-magnesium soaps which are ineffective for cleansing purposes. Very little cleaning occurs until these ions are present. Therefore, the soap is deactivated quantitatively and much more soap is required when hard waters are used for cleansing purposes.
Hard water also interferes with almost every cleaning task including laundering and dishwashing to bathing and personal grooming. Clothes laundered in hard water may look dingy and feel harsh and scratchy. Dishes and glasses may be spotted when dry. Hard water may cause a film on glass shower doors, shower walls, bathtubs, sinks, faucets, etc. Hair washed in hard water may feel sticky and look dull. Water flow may be reduced by deposits in pipes.
Before looking at the occurrence of hard water, it is worth stating that despite these problems, the introduction of a water softener system can deal with many of the problems at source. There are many options available for such systems and we recommend you review the options before coming to a final decision.
Occurrence of Hard Waters
Calcium and Magnesium which are the main constitutive of hard water dissolved from limestone, dolomite, and other minerals when water comes in contact. Ground waters generally contain much greater concentrations of hardness than that found in surface waters. An example of hard water occurrence in nature can be seen in Figure 1 where a layer of 20-centimeter thick is formed in Eifel aqueduct in Germany during 180 years where calcium has precipitated gradually.
A portion of the ancient Roman Eifel aqueduct in Germany. In service for about 180 years, the aqueduct had deposits of scale up to 20 cm thick along the walls.
Problems of Water Hardness
- Increased soap consumption in hard waters is probably the most disadvantage of hardness. Much of this disadvantage has been eliminated by the increased use of synthetic detergents, but where soaps are used the increased cost is significant.
- Process waters containing hardness when used in textile, paper, canning, and other industries can cause considerable deterioration in product quality.
- Boiler feed water containing hardness can cause scale buildup.
In boilers, the precipitation will damage and slows down the flow of heat into water, causing the heating efficiency and allows the metal boiler to overheat. The damage caused by calcium carbonate precipitate differs, for example, calcite or aragonite (magnesium ore).
- Health considerations. The World Health Organization says that “there does not appear to be any convincing evidence that water hardness causes adverse health effects in humans” In fact, the United States National Research Council has found that hard water can actually serve as a dietary supplement for calcium and magnesium. Recommendations have been made for the maximum and minimum levels of calcium (40–80 ppm) and magnesium (20–30 ppm) in drinking water, and a total hardness expressed as the sum of the calcium and magnesium concentrations of 2–4 mmol/L. Hardness in water can clog skin pores
- Hardness in water stain fabrics
- Hardness in water can clog skin pores
- Hardness toughen and discolor vegetables