Memory Anchor:

• Super Challenge:

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  Challenge:

Key Questions:

1. What should the quality of drinking water be like?
   • The quality of drinking water should have low levels of dissolved salts and microbes.
2. What must be done to the waste water produced by urban lifestyles and industrial processes before it can be released back into the environment?
   • Urban lifestyles and industrial processes produce large amounts of waste water that require treatment before being released into the environment.
3. What is the name given to water that is safe to drink?
   • The name given to water that is safe to drink is potable water.
4. What will be required to be removed from a) agricultural waste water and b)industrial waste water?
   • Agricultural waste water require removal of organic matter and harmful microbes. Industrial waste water may require removal of organic matter and harmful chemicals.
5. What factors decide which methods are used to produce potable water?
   • The methods used to produce potable water depend on available supplies of water and local conditions.
6. What does sewage treatment include?
   • Sewage treatment includes: - screening and grit removal - sedimentation to produce sewage sludge and effluent - anaerobic digestion of sewage sludge - aerobic biological treatment of effluent.
7. What stages do most of the potable water in the UK produced?
   • The stages that most potable water is produced in the UK is: - choosing an appropriate source of fresh water - passing the water through filter beds - sterilising.
8. How is potable water obtained from a) waste ground and b) salt water?
   • Potable water can be obtained from waste ground through the three main stages of sedimentation, filtration and sterilizing. Potable water can be obtained from salt water through desalination by distillation or reverse osmosis.
9. What are three types of sterilising agents used for potable water?
   • Sterilising agents used for potable water include chlorine, ozone or ultraviolet light.
10. What process can be used to make salt water / sea water potable when fresh water is limited?
    • If supplies of fresh water are limited, desalination of salty water or sea water may be required.
11. How is desalination completed? (give two methods)
    • Desalination can be done by distillation or by processes that use membranes such as reverse osmosis.
12. What is the main drawback of desalination processes?
    • Desalination processes require large amounts of Energy.
13. What is the difference between potable and pure water?
    • Pure water only contains water Particles with no other substances. Potable water is safe to drink but contains other soluble ions.
14. What is the differences in the way that ground water and salty water is treated?
    • Salty water is treated by distillation or by reverse osmosis. Ground water is treated by - passing the water through filter beds and then sterilising using chlorine, ozone or UV light.
15. What are the reasons for each step of producing potable water from ground water?
    • Potable water is filtered to remove any fine Particles in the water. It is then steralised to kill microbes.