Using resources Flashcards
where do natural resources come from
The earth sea and air
what are some examples of renewable sources
Trees
fresh water
food
what are some examples of finite sources
fossil fuels
nuclear fuels
minerals + metals found in ores
what are finite materials
they arent formed quickly enough to be considered replaceable
what is an example of natural product that has been replaced by synthetic products
rubber is extracted from the sap of a tree but man made polymers have been made which can replace rubber.
what is sustainable development
development that takes in account of the needs of present society but doe snot damage the lives of future generations
how can we improve coppers sustainability
by extracting it from low grade ores ( ores with not much copper in it)
what are the two methods scientists are using to increase the sustainability of copper
- bio leaching
- phytomining
how are metals recycled
by melting them and then casting them into a new product
how is glass recycled
crushed then melted to be reshaped.
what is the purpose of a life cycle assessment
to assess the environmental impact of products
what are teh four main stages of the life cycle assessment
getting raw materials
manufacturing and packaging
using the product
product disposal
how does extracting raw materials directly damage the environment
- cutting down forests
- digging huge mines
how does processing raw materials indirectly damage the environment
because of the huge amount of energy required
can also release pollutants
how can manufacturing and packaging damage the environment
uses a lot of energy
causes pollution - harmful fumes
chemical reactions used to make compounds from raw materials creates waste products - manufacturer must think how to dispose of them - etc turn them into useful chemicals
how can using a product damage the environment
- how much damage is does in its life time
- how long a product is used for - etc paper bag + expensive bag
how does product disposal damage the environment
- products disposed on landfill - takes up space that could be used for nature and it could pollute land and water
- energy used to transport waste to the land fill which causes pollutants
- if products are incinerated it causes more pollution
what is the raw material for a plastic bag
crude oil
what are the limitations of life cycle assessment
- making products require loads of different steps and it can be difficult to quantify all of them
- Companies can manipulate their LCAs to look more favourable
-It is difficult to compare different harms e.g. lung disease vs global warming
what is potable water
water that is safe to drink
why isn’t potable water pure
because in chemistry pure water would only contain h20 molecules but potable water often contains other dissolved substances
What are the three criteria for water to be considered potable?
- ph between 6.5 and 8.5
- no microorganisms
- the level of dissolved substances has to be low ( like salt)
Where does the UK get most of its potable water from?
fresh water sources
what are aquifers
areas of permeable rock under the ground that traps water
What are the benefits of relying on fresh water?
it is replaced frequently
it is easy to access
when is rains where can water collect
as surface water
as ground water
what are the steps in treating fresh water to make sure it is safe to drink
- filter through a wire mesh to get rid of large objects like bottles and twigs
- pass water through sand or gravel which will filter out anything smaller things
- lastly sterilise to kill any harmful bacteria
what are the different ways of sterilising fresh water to kill bacteria
expose it to ultraviolet radiation
expose it to ozone
bubbling chlorine gas through it
what is desalination
the process to extract potable water from sea water
what are the two processes of desalination
distillation and reverse osmosis
what is the major drawback of desalination
its uses loads of energy and is very expensive which makes them impractical when producing large quantities of water
why might some countries use desalination
in dry countries there is not enough surface or ground water so they instead use sea water
what is reverse osmosis
- salty water passed through a membrane that only allows water molecules through
what is an example of agricultural water waste
nutrient run-off
what is an example of domestic water waste
shower water
toilet
washing up
what is an example of industrial water waste
harmful chemicals
what has to be removed from sewage and agricultural waste water before the water is returned to the environment?
harmful microbes
organic matter
Which gaseous product does the anaerobic digestion of sludge produce?
methane
what are the steps in the treatment of sewage
- screening - passed through gratings to remove anything large
- goes into a settlement tank so heavier particles sit at the bottom and turn into sludge while the light particles settle at the top as effluent
- aerobic digestion - air pumped through effluent to provide bacteria with oxygen
- anaerobic digestion - sludge is sealed to prevent entry of air -
what does the anaerobic digestion do to the sludge
it breaks down the organic matter and releases methane
why can the methane be used for produced by anaerobic digestion
as an energy source
as a fetiliser
what does the aerobic digestion do to the effluent
air is pumped through to make aerobic bacteria break down organic matte
