Question

What are the different steps in large scale water purification? [5 marks]

Answer 1

The different steps in large scale water purification are:

1. Water is first pumped from rivers or lakes to large tanks of water works. [1 mark]
2. Water is allowed to stand in large sedimentation tanks for few hours. [1 mark]
3. The clear water from sedimentation tank is filtered through a layer of sand and gravel. It can also be done through activated charcoal which gives better quality water. [1 mark]
4. The water is then disinfected using chlorine gas. This kills germs, and harmful bacteria. [1 mark]
5. The purified water is then pumped into the supply system. The water is used for drinking and household purposes. [1 mark]