Page 11 - REMOVING IMPURITIES FROM WATER AND PURIFYING IT (2)
P. 11
•Water is collected in large tanks and allowed
to stand for a few days. This allows heavy
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impurities to settle down by sedimentation.
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•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.
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•Water is allowed to pass through filters made of
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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.
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•After this process, water is supplied to our homes
through pipelines.
