Potable Water

Question 1

What is potable water

Answer 1

Water that has been treated or is naturally safe for humans to drink

Question 2

What is the difference between pure water and potable water

Answer 2

• pure water is H2O molecules only

- potable water contains other dissolved substances

Question 3

What are the different steps in water waste treatment

Answer 3

1. Screening and grit removal
2. Sedimentation to produce sewage sludge and effluent
3. Anaerobic digestion of sewage sludge (bacteria without oxygen)
4. Aerobic biological treatment of effluent (bacteria with oxygen)
5. UV light can be used to kill bacteria

Question 4

What are the stages to producing potable water

Answer 4

• we take fresh water (rain water or surface water(rivers or lakes))
• filtration: a wire mesh screens out large twigs, etc. Then gravel and sand beds filter anything else out
• Sterilisation: water is sterilised to remove bacteria or microbes. This is done bubbling chlorine gas or using ozone or ultraviolet light

Question 5

Other ways to produce potable water

Answer 5

• distillation
• reverse osmosis: salty water passed through a membrane that allows water molecules to pass through, trapping any ions or larger molecules and sepperating it from the water
• However both are expensive and require a lot of energy