Using the Earth’s resources and obtaining potable water Flashcards
Why do we need earth’s resources (4)
- Warmth
- Shelter
- Food
- Transport
What do natural resources provide? (4)
- Food
- Timber
- Clothing
- Fuels
Define ‘renewable energy resource’
sources of power that quickly replenish themselves and can be used again
What is potable water?
Water that is safe to drink
True or false - “Potable water is pure water”
False - It contains dissolved substances
Why is rain a good source of fresh water?
Low levels of dissolved substances
Where does rain collect?
- Ground
- Rivers
- Lakes
First stage of water treatment
Water passed through filter beds to remove different sized insoluble solids
Second stage of water treatment
Water is sterilised to kill microbes
State 3 Sterilising agents
- O zone
- UV
- Chlorine
What needs to happen if only salty water is available?
Desalination
State 2 ways desalination can be done
Distillation, processes with membranes (reverse osmosis)
What are the drawbacks of desalination methods?
- Very expensive
- Requires a lot of energy
First Stage of Waste Water Treatment
Water passed through mesh screen to remove large bits, e.g twigs
Second Stage of Waste Water Treatment
Chemicals are added to make microbes stick together to form sediment
Third Stage of Waste Water Treatment
Anaerobic digestion of sewage sludge
Fourth Stage of Waste Water Treatment
Water sterilised with chlorine to kill microbes
Why are groundwater and wastewater good ways to obtain potable water?
Cheaper and easier than salt water
Why can salt water be better that ground/waste water?
Plentiful raw material
Which countries get potable water from the sea?
Those with little fresh water
Earth’s resources of —- are —–
Metal ores, limited
What are two ways of extracting copper from low grade ores?
Phytomining, bioleaching
