Using Resources (Unit 10) Flashcards
Define Sustainable Development
Development that meets the needs of people today without compromising the ability of future generations to meet their own needs.
What are ‘finite’ resources?
Resources that can run out
What are ‘renewable’ resources?
Resources that can be easily replaced as they are used up
Define ‘sustainable’
Maintained at a certain level over long periods of time
What is potable water?
Water that is safe to drink
- there are low levels of dissolved salts/minerals
- free of microbes
Who needs potable water?
Humans: to drink
How do you treat ground water?
1) Choose fresh water source (e.g. rain, ground, rivers)
2) Filter out the solids
3) Sterilise to kill microbes
More specifically, how do you treat ground water?
1) Water is collected at a resevoir
2) Large insoluble objects are filtered (SCREENING)
3) Water is passed through sand and soil sediment where small particulates are filtered off
4) Chemicals added to rid of small particles
5) Treated to kill bacteria and pH is check to ensure it’s neutral
6) Water transported to homes, factories, offices
Name three ways water is sterilised.
Chlorine
Ozone
UV rays
When would one try to treat salty water?
In hot countries near the sea with little ground water/rain
What is an issue of treating salty water?
It is expensive
- as it requires a lot of energy
How do you treat salty water?
DESALINATION of salty water
- distillation (evaporated and condense water form salty solution)
- reverse osmosis (filter water via semi-permeable membrane)
What is the issue of reverse osmosis?
It requires a lot of energy
What’s different about treating waste water?
Have to remove organic matter using harmful chemicals
Define waste water
Sewage or dirty water
How do you treat waste water?
1) Screening: remove solids
2) Sedimentation: filter water through sediment to filter out smaller particles. This produces SEWAGE SLUDGE and EFFLUENT
3) Sewage sludge (solid, viscous) is processed by ANAEROBIC DIGESTION to remove harmful microorgansims from organic matter
4) Effluent (water bit) is treated by ANAEROBIC BIOLOGICAL TREATMENT which allows ‘good’ bacteria to feed of ‘harmful’ microorganisms. This is called AERATION