Page 416 - Primary Six Notes

Preparation of safe water for drinking

Water is prepared for safe drinking by boiling, filtering and

treatment.

1. Boiling

When water is heated, it boils to a temperature of 100 C
0
(212 F). This temperature kills germs.
0

2. Filtering

Water filtering is the process by which a porous device, such
as a piece of cloth, is used to remove impurities or solid parti-

cles from water. Examples of solid impurities filtered are dirt,

soil, stones, leaves, animal wastes etc.

Filtered water may not be safe for drinking because it may

contain some germs.

3. Treatment of water

Treatment of water is when chemicals are added to kill germs

in it.

The chemicals kill germs in water

Disadvantages of using chemicals

 They are expensive

 They do not make water clear

 They may add some smell and taste to water