C10 - Using Resources Flashcards
Describe 3 things humans use Earth’s resources for
Humans use the Earth’s resources to provide warmth, shelter, food and transport
Describe what is meant by non-renewable resources and give 4 examples of it
Fossil fuels and nuclear fuels
Minerals and metals found in ores in the earth
Give examples of natural products that are supplemented or replaced by agricultural and synthetic products ( 3 marks)
Rubber is a natural product that can be extracted from the sap of a tree - man made polymers can replace rubber
Development of fertilisers have meant we can produce a high yield of crops
What is meant by sustainable development
Meeting the needs of today without harming the lives of future generations
Describe the alternative biological methods of metal extraction ( 6 marks)
Phytomining uses plants to absorb metal compounds. The plants are harvested and then burned to produce ash that contains metal compounds.
Bioleaching uses bacteria to produce leachate solutions that
contain metal compounds.
Metal compounds can be processed to obtain the metal. For example, copper can be obtained from solutions of copper compounds by displacement using scrap iron or by electrolysis.
Describe the benefits of recycling materials over mining and extracting new metal ( 3 marks)
Recycling metals often uses much less energy than is needed to mine and extract new metal
Conserves the final amount of metal in the earth
Cuts down amount of waste getting sent to landfill
Describe two ways in which metals/glass are recycled( 2 marks)
Metal -Melting or casting them into the shape of the new product
Glass - crushed then melted to be reshaped for use
What are Life Cycle Assessments used for
Looking at every stage of a products life to assess the impact it would have on the environment
What four things does a life cycle assessment asses
extracting and processing raw materials manufacturing and packaging
use and operation during its lifetime
disposal at the end of its useful life, including transport and
distribution at each stage.
Compare the use of plastic and paper bags via LCA stage:
Raw Materials
Manufacturing and Packaging
Using the product
Product Disposal
Plastic bag - crude oil - Paper bag - timbers
Compounds needed to make plastic extracted from crude oil - plastic
Pulped timber is processed using lots of energy - lots of waste made - Paper
Can be reused - used for other things as well as shopping
Usually only used once - timber
Recyclable but not biodegradable takes up space in landfill and pollute land
Biodegradable - non-toxic and can be recycled
Describe the problems/advantage with LCA ( 6 marks)
bias, quantified
Use of energy, some natural resources and amount of certain types of waste by a product over its lifetime can easily be quantified
Effect of some pollutants is harder to give a numerical value
Producing an LCA is not objective method as it takes into account the values of the person carrying out the assessment - LCA could be biased
Selective LCAS - only show some of the impacts of a product on the environment - could be biased
What is potable water and pure water
Potable water - water that’s been treated or is naturally safe for humans to drink
Pure water - water that only contains H2O molecules where as potable water contains lots of other dissolved minerals
In warm areas where do most of the water supply come from
Groundwatrer
Describe how fresh water is treated to make it safe ( 4 marks)
Filtration - wire mesh screens out large bits twigs and then gravel and sand beds filter out any other solid bits
Sterilisation - water is sterilised to kill any harmful bacteria or microbes - can be done by bubbling chlorine gas through it or by using ozone or ultraviolet light
In dry countries where do most of their water supply come from and how is it treated
sea water - desalination through distillation
- reverse osmosis
What are the downsides of distillation and reverse osmosis
Expensive and requires loads of energy - not practical for large volumes of water
Why do we treat sewage water
Needs to be treated before it can be put back into freshwater sources
What are the stages to treat sewage water ( 6 marks)
Screening and grit removal
Stand in a settlement tank - undergoes sedimentation to produce sludge and effluent
Effluent in settlement tank is removed anaerobic digestion of sludge
Aerobic biological treatment of effluent to break down any organic matter
