C14 - The Earth's Resources Flashcards
Define finite.
will run out
Define infinite/renewable.
will not run out
What can the Earth’s resources provide us with?
shelter, food, trnsprt, & fuel
Name 2 types of resources.
- synthetic
- natural
When choosing resources, what do we have to consider?
sustainable development
Define sustainable development.
meeting current generations’ needs without compromising future generations’ needs
Give an example of a finite resource.
fossil fuels
Give an example a renewable resource.
wood
Define potable water.
safe -> drink
What does pure water have in it?
just H2O molecules
What does potable water have in it?
- H2O molecules
- low lvls of salt
- safe lvls of harmful microbes
What does sea water have it?
- H2O microbes
- dngrsly high lvls of salt
- (possible) high lvls of hrmfl microbes
What does fresh water have in it?
- H2O mlcls
- low lvls of salt
- (often) high lvls of hrmfl micrbs
How do you produce potable water in the UK?
- choose appropriate fresh water source
- pass H2O through filter beds -> remove lrg objects
- strlse water -> kill mcrbs using ozone, chlorine or UV light
What do we use to sterilise water in the UK?
chlorine
What are sources of fresh water in UK?
rivers, lakes or underground
In countries, where the water available is mostly sea water, how can potable water be produced?
desalination
What are 2 ways of carrying out desalination?
- distillation
- rvrs osmosis
How does reverse osmosis reduce salt levels in water?
passes H2O through membranes -> separate salts dissolved in H2O
What is a disadvantage of both distillation & reverse osmosis?
requires lrg amounts of energy = v £££
Name 3 types of waste water.
sewage, agricutural & industrial waste
What does sewage and agricultural waste contain?
organic matter & hrmfl mcrbs
How is sewage water initially treated?
- sewage screened by passing through mesh -> filter out solids & grit
- sewage settles in sedimentation tanks
- producing liquid effulent & semi - solid sludge
What happens to the semi - solid sludge, after intial treatment of sewage water?
bacteria added & break down matter anaerobically
