The Earth's Resources Flashcards
What do Humans use the Earth’s resources to do?
provide warmth, shelter, food
and transport.Natural resources, supplemented by agriculture, provide food, timber, clothing and fuels.
What is potable water?
Water that is safe to drink is called potable water.
Potable water is not pure water in the chemical sense because it contains dissolved substances.For humans,
drinking water should have sufficiently low levels of dissolved salts and microbes.
How is potable water produced in the UK?
rain provides water with low levels of
dissolved substances (fresh water) that collects in the ground and inlakes and rivers, and most potable water is produced by:
* choosing an appropriate source of fresh water
* passing the water through filter beds
* sterilising.
What are the sterilising agents for potable water?
Sterilising agents used for potable water include chlorine, ozone or
ultraviolet light.
What happens if fresh water supplies are limited?
desalination of salty water or sea water may be required. Desalination can be done by distillation or by processes that use membranes such as reverse osmosis. These processes require large amounts of energy.
What is sewage treatment?
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent.
What are metal ores?
naturally occurring rocks that contain metals or metal compounds in sufficient amounts to make it worthwhile extracting them.
Copper ores are becoming scarce and new ways of extracting copper from low-grade ores. How?
phytomining, and bioleaching. These methods avoid traditional mining methods of digging, moving and disposing of large amounts of rock.
What is phytomining?
Phytomining uses plants to absorb metal compounds. The plants are harvested and then burned to produce ash that contains metal compounds.
What is bioleaching?
Bioleaching uses bacteria to produce leachate solutions that contain metal compounds.
How can copper can be obtained from solutions of copper compounds?
by displacement using scrap iron or by electrolysis.
Life cycle assessments (LCAs) are carried out to assess the environmental impact of products. What are the stages?
- 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.
Ways of reducing the use of resources?
The reduction in use, reuse and recycling of materials by end users reduces the use of limited resources, use of energy sources, waste and environmental impacts
How are Metals, glass, building materials, clay ceramics and most plastics produced?
are produced from limited raw materials. Much of the energy for the processes comes from limited resources. Obtaining raw materials from the Earth by quarrying and mining causes environmental impacts.
How can glass be reused?
Glass bottles can be crushed and melted to make different glass products
