The water may consist of different types of impurities like minerals, metals, gases, bacteria, and chemicals. Many of these contaminants can be deter mental to your health. Hence one should treat the water before consumption. Water can be made harmless through various methods so that all the pathogens are destroyed and contaminants filtered.
Disinfecting Water
Water disinfection can be effected using following methods:
Chlorination
Chlorine addition is one of the most effective means for disinfection of water both or municipal and private supplies. Chlorination is cheap and effective method for killing harmful pathogens and microorganism like bacteria, virus and cyst organisms. It also effective against non-pathogenic iron, manganese and sulfur bacteria. Chlorine is used as sodium hypochlorite (contains 5% available chlorine) for home use. Chlorine also comes in dry pellets and has (70 percent available chlorine). Water chlorination can be done in the following way:
- In dry form
- In liquid form
- Injected into well by using a chemical feed pump
Shock chlorination is done in the following cases:
When the well is constructed recently
- It is contaminated.
- If surface water has entered into the well.
- To control the problem of iron bacteria.
- Warn every one not to use that water.
- Provision of drinking water should be made before doing a shock chlorination.
- You must posses all the necessary equipments before beginning shock chlorination.
In Continuous disinfection chlorine is added to all water drawn from the source. Chlorine when mixed properly, kill all microorganism that are disease causing. It is the concentration of the chlorine temperature, and pH. The time required for disinfection depends on the concentration of chlorine, temperature and pH of the water.
Ultraviolet Light Disinfection
Ultraviolet light is a recent development in water treatment field. Ultraviolet radiation does not alter taste and the odor of the water. Mercury vapor lamp is used for producing UV light that produces disinfecting dose. The dose of 20,000 Mws/cm2 is capable of killing most of the pathogenic bacteria. To disinfect viruses dose of 45,000 Mws/cm2 is needed. The device used for disinfection consist of stainless cylindrical chamber having mercury arc lamp. When water enters the chamber it comes into the effect of the lamp and then exits. For successful disinfection radiation must pass through through every particle of water. For effectiveness of the system it is necessary that water film is thinner and the water flow is slower.
Distillation Disinfection
Distillation is effectively used for reducing nitrates, dissolved salts like chlorides, sulfates and carbonates of sodium, potassium, magnesium, and other organic matters. The unit is designed to boil the water and then condense the steam to collect the pure water.
Other Methods of Treatment
Some other methods that are used as a emergency measure on a temporary basis to treat water are:
- Boiling
- Chlorine Bleach
- Granular Calcium Hypochlorite
- Chlorine Tablets (Halazone)
- Iodine Tablets
