Page 5 - REMOVING IMPURITIES FROM WATER AND PURIFYING IT

PURIFYING DRINKING WATER

 We all need clean drinking water to stay fit. However, pollution and germs
cause water to get contaminated. Contaminated water can cause diseases
such as typhoid and cholera. Therefore, water needs to be purified before
consuming it.

 At home, this can be done by boiling and using water purifiers.
 Boiling is a very effective method that has been in use for a very long time.
Boiling water kills germs. These days’ water purifiers are also being used to
purify water.
 Before the water from various sources reaches us, it is treated in
purification plants.

 The three main methods involved in treating water in a water- treatment
plant are:
1. Sedimentation
2. Filtration
3. Chlorination

 Water is collected in large tanks and allowed to stand for a few days. This

allows heavy impurities to settle down by sedimentation.
 The harmful bacteria present in the water are killed by the action of air
and sunlight. Chemicals such as alum are also added to purify water.
 Water is allowed to pass through filters made of sand and gravel. This
helps in removing suspended impurities such as clay and mud.
 Then chlorine is added to the water to kill germs. This process is known
as chlorination.

 After this process, water is supplied to our homes through pipelines.