| p>Water is a vital necessity for mankind--it is used | | | | power to kill the bacteria. UV filters use this |
| for drinking, cooking, bathing, washing clothes and | | | | effectively in the treatment of water. However, UV |
| utensils, gardening, pets, cleaning, agriculture, and | | | | filters do not make the water soft or remove the |
| boilers and water heaters. Water is almost invariably | | | | odors. |
| contaminated with acidity, salts, metals, color, odor, | | | | The Reverse Osmosis (RO) system uses |
| taste, and other organic pollutants like insecticides and | | | | semi-permeable membranes for the purification of |
| herbicides and bacteria and microbes. Hence, one | | | | water. They filter out almost all unwanted impurities |
| must resort to purification before consumption. | | | | like magnesium, calcium, iron, and smelly compounds |
| Water softener systems are ion-exchange resins | | | | and bacteria. This process gives only about 10% of |
| that replace the calcium and magnesium salts present | | | | the input water. The domestic RO units usually |
| in hard water with sodium ions. The soft water thus | | | | contain a five-stage purification process: a pre-filter, a |
| obtained is good for bathing and for use in | | | | sediment filter, a bactereostatic carbon filter to |
| dishwashers and washing machines. Soda ash | | | | remove color and odor, an ultra filtration membrane |
| neutralizes the acidity of water and is widely used for | | | | to remove bacteria and viruses, and a polisher to |
| the purpose. When the water is alkaline, one resorts | | | | ensure removal of bacteria completely. |
| to citric acid to neutralize the alkalinity. | | | | One should test the input water and take appropriate |
| Activated carbon filters are widely used for the | | | | measures for purification. Also, tests should be carried |
| treatment of water with strong smell of rotten eggs | | | | out at regular intervals to ensure the systems |
| or garlic. Activated carbon filters work based on the | | | | function as per specifications. |
| principle of adsorption. Ultraviolet radiation has the | | | | |