| Natural rainwater is soft. When this rainwater reaches | | | | sodium bicarbonate. The water can also be softened |
| the ground it absorbs earth minerals like calcium, | | | | by the processes like resin ion exchange, chelating |
| magnesium, chalk, lime etc. So the water becomes | | | | and also with the help of physical conditioners. |
| hard. Though hard water contains essential minerals | | | | Household water softening equipments use ion |
| they cannot be used as they have lots of | | | | exchange resins. In this process the water is passed |
| disadvantages. | | | | through the bed of resin. Based on the harness of |
| Hard water cannot be used for cleaning, as they are | | | | the water the ion exchange resin is selected. The |
| not efficient for this purpose. It cannot be stored for | | | | ions contain negatively charged particles. When it |
| a long time as they form scales. Knowledge about | | | | passes through it its negatively charged particles |
| how to soften hard water is needed so as to make | | | | attract the positively charged metal ions in hard |
| the water suitable for its intended purpose. | | | | water. |
| Sodium and calcium in it precipitates on heating. So | | | | So the calcium and magnesium ions remain on the |
| they cause adverse effect on the boiler walls. | | | | resin and the ion free water is collected. When the |
| Precipitation of their salts on the walls of the boilers | | | | resins are used continually they lose their |
| causes failure of the boilers during pressurization. | | | | effectiveness due to the accumulation of calcium and |
| They also corrode the pipes through which they flow. | | | | magnesium. So it can be cleaned by passing |
| So it is necessary to remove them and make them | | | | concentrated brine solution on it. |
| soft. | | | | Chelating agents like citric acid can be used to soften |
| When it is softened the minerals like calcium and | | | | water, which can be used for laundry purposes. |
| magnesium are removed and the sodium stays in it. | | | | These chelating agents are found in detergents and |
| Calcium and magnesium ion concentrations are greatly | | | | shampoos. |
| reduced. The most popular softening agent used is | | | | |