C10 Natural resources Flashcards
What do we use the Earth’s resources for?
Warmth, shelter, food and transport
How do we use agriculture to maximise these resources?
To provide food, timber, clothing and fuel
What does the term finite mean?
There is a limited amount so we will run out of it eventually
What is potable water?
Water that is safe to drink
What does water need to have to be classed as potable?
Low enough levels of dissolved salts and microbes
How can fresh water be made potable?
Filtering the water through filter beds and then sterilising it
How can water be sterilised?
Using chlorine, ozone of UV light
How can salt water be made potable?
Remove the salt by distillation or reverse osmosis
Why fresh water a better source of potable water than salt water?
It requires less energy to make potable
How are potable and pure water different?
Pure water has no other chemicals in it, potable has other chemicals in it but at low enough levels so it is safe to drink
How is sewage treated before being released into the environment?
Screening and grit removal, sedimentation, anaerobic digestion of sewage sludge, aerobic treatment of effluent
Why is fresh water a better source of potable water than waste water?
There are a lot more stages in making waste water potable
What are low grade copper ores?
Rocks that have a small percentage of copper in them
Why are new methods of extraction needed?
“Traditional methods of digging, moving and disposing of large amounts of rock are more expensive, use lots of fuel and produce lots of waste.
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What is phytomining?
Using plants to absorb metal compounds from the ground. The plants are harvested and then burned to produce ash that contains metal compounds
What is bioleaching?
Using bacteria to produce leachate solutions that contain metal compounds
What are the 4 stages of a life cycle assessment?
Extracting and processing the raw materials, making and packaging the product, using the product, disposing of the product
What is looked at at each stage in a LCA (life cycle assessment)?
The water, resources and energy used, the pollution and waste produced, including affects of transport.
Why is it hard to quantify pollution effect?
It is subjective, people may disagree about which pollutant is worse.
Why are partial LCA a problem?
They can be misused to support a claim for advertising that might not be true. They can be biased.
What are the advantages of reducing use of or reusing and recycling materials?
It saves limited resources, saves on energy sources, reduces waste products and environmental impact
Give some examples of materials that come from finite resources
Metals, glass, building materials, clay ceramics and plastics