Rescources Flashcards
(20 cards)
What are resources used for?
Warmth, shelter, food and transport
What is agriculture?
Farming
What’s a finite resource?
Cannot be replaced quickly as being used e.g fossil fuels
What does renewable mean?
Can easily be replaced
What does sustainable mean?
Meeting our needs
What do artificial fertilisers allow us to do?
Allow us to grow more food with the land available
What is potable water?
Water that’s safe to drink
What does potable water contain?
It contains dissolved substances
How do u produce potable water?
1) choose a good source of fresh water e.g a river
2. ) pass the water through a filter bed to remove materials like leaves
3. ) the water is then sterilised to kill microbes
4. ) chlorine is used to sterilise potable water
5. ) the salty water is passed through a membrane which lets water through but traps salts.
What is potable water produced by?
By desalination
What’s is desalination?
It reduces the levels of dissolved minerals
How can u use desalination?
U can use distillation
What’s another way of producing potable water?
By reverse osmosis
Why are both processes expensive?
Both require lots of head and energy
Describe the water practical…
- ) check Ph of water by placing it on universal indicator
- ) if it’s green then it’s 7
- ) use an evaporating basin and record mass
- ) fill basin with water sample and use a Bunsen burner to head water until it’s evaporated
- ) let it cool and weigh again
- ) if water contained dissolved solids then mass will increase as water evaporates and crystals are formed.
Describe the distillation practical…
- comical flask contains water sample
- place flask on a tripod and gauze
- top part of flask has a delivery tube pointing to test tube
- test tube sits in beaker containing ice & water
- heat water which will evaporate and form steam
- water vapour travels along collecting tube
- when water vapour enters cold test tube it condenses back to liquid
- this is distilled water
- has a Ph of 7 and contains no solids so it’s pure
Describe the waste water treatment…
- sewage is screened by passing through a mesh which removes Solids
- sewage allows to settle in large sedimentation tanks to produce sludge which is digested by anaerobic bacteria
- bacteria produces bio gas which is burnt for electricity
- sludge can then be used for farming
- the liquid effluent contains large organic molecules and microorganism that need removing
- air is bubbles through liquid to allow anaerobic bacteria to multiple and digests the microorganisms and molecules
Continue…
- liquid effluent is safely discharged into rivers or sea
- water is then safe to drink once treated with chlorine
What’s the lifecycle assessment?
Life cycle of a product e.g plastic bags etc
Why is extracting metals expensive?
Takes a huge amount of energy
