Importance of Water Treatment
Treatment of water is so important that we can avoid many possible water borne diseases like cholera, typhoid, jaundice and so on. It's true that water borne infections are responsible for more than 80% of the diseases in all over the world. Whenever there is contamination of drinking water sources and water logging after rain there is in an outbreak of infection.
Potable Water and its Sources
Safe, 100% pure and odour free water can be defined as potable one. This should be free from disease carrying micro organisms and dangerous chemical substances. Rain, Surface water (reservoir, stream and tank) and Ground Water (shallow wells, deep wells and springs) are three main sources of potable water. In urban areas and big towns, the corporation and municipality hold the full responsibility of treating water from surface sources and supplying to people.
Pollutants that Commonly Found in Natural Water
Naturally found water is not a pure water and it contains many dissolved and suspended impurities. All of the impurities are derived from atmosphere, catchment areas and soil. Hydrogen Sulphide, oxygen, ammonia, sodium and calcium carbonates (dissolved impurities) and clay, silt, sand, mud and microscopic plants (suspended) are some of the commonly found impurities of water. The most hazardous water pollution is caused by urbanization and industrialization. Industrial waste contains toxic agents ranging from metallic salts to complex synthetic organic chemicals. Whenever the water is polluted bsy these things, it will make serious health complications to animals, plants and human beings living in surrounding areas. Particularly sewage contains decomposable organic matter and disease creating chemicals. The fertilizers, pesticides such as DDT, Aldrin and Dioxin are some of the agricultural pollutants of water.
Hazards of Polluted Water
These are caused by the micro organism germs present in the drinking water. The water borne disease that comnmonly spread are cholera, gastric problem, typhoid, dysentry, round worm infestation, guinea worm infestation and jaundice. We can simply avoid above said all the diseases boiling water before using it.
Nowadays growth of chemical and other industries all over the world has become the main reason for the pollution of surface water. Every country is holding the responsibility to find out the level of pollution which won't affect the general health of people and animal living around polluted water. Detergents, solvents, cyanides, heavy metals, minerals, organic acids and bleaching agents are something which are responsible for serious health problems to mankind. Polychlorinated biphenyls present in water cause serious skin infections and intestinal disorders. Disorders of liver, bone and circulatory system are caused by vinyl chlorides and anaemia, bone marrow damage and leukaemia are by benzene. Pthalates found in water are responsible for the damage to human nervous system and Nitrosamine causes carcinogenic problem.
Various Methods of Purification of Drinking Water
Boiling and Filtering
This an easy and satisfactory method of purification in households. Water is roll boiled for five to ten minutes as we can kill all the germs that present in it. We can also reduce hardness of water by boiling it as carbon di oxide and calcium carbonate will be driven off. However we need water filter to separate precipitated calcium carbonate and other suspended impurities.
Dissolving Bleaching Powder
This method of purification can be used when water is stored in overhead tanks and obtained from wells. Bleaching powder, chlorinated lime with pungent smell, is commonly used chemical for the purification of water. 2.3 gm of bleaching powder will be required to purify about 1000 litres of water.
These are nowadays also available in pill form. One pill of chlorine weighing 0.5 gm is enough to disinfect about 20 litres of water. Potassium permangnate and iodine are also used for the purification purpose. But, they are nor preferred because of their side effects.
Using Different Types of Filters
Porcelain candle filters and U-V filters are commonly used for the filtration of water.
Porcelain candle filters
A candle made of porcelain or infusorial earth. The surface is coated with silver so that the bacteria coming in to contact with it is killed. However this method in not effective in removing ultimate pure water. It's also necessary to clean the candle as it gets clogged with coagulated bacteria and other impurities.
This type of water filters are smaller in size as they can be easily handled and installed in our home. There is no need of special tool to maintain it. Every UV water filter is provided with UV light and patented carbon block filter which will be hepful to avoid more than 125 health effect contaminants.