Using Resources (10) Flashcards
(47 cards)
What is sustainable development?
Development that meets the needs of current generations without compromising
the ability of future generations to meet their own needs
In the UK, potable (safe to
drink) water is produced by…?
• choosing an appropriate source of fresh water
• passing the water through filter beds to remove any solids
• sterilising to kill microbes
What are the sterilising agents
for potable water?
Sterilising agents used for potable water include chlorine, ozone or ultraviolet light.
• Chlorine is a toxic gas so the amount added to water has to be carefully
monitored.
• Using ultraviolet light to kill microbes avoids adding chemicals to the water but is
more expensive
How is desalination carried
out?
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 reverse osmosis?
Sea water is passed through a membrane that only allows through the water
molecules. It needs high pressure to push the water through the membrane. The
high pressure requires a lot of energy to produce.
How is wastewater produced and how is it treated? (Urban lifestyle)
Urban lifestyles and industrial processes produce large amounts of waste water
that require treatment before being released into the environment.
How is wastewater produced and how is it treated? (Sewage)
• Sewage and agricultural waste water require removal of organic matter and
harmful microbes.
How is wastewater produced and how is it treated? (Industrial waste)
Industrial waste water may require removal of organic matter and harmful
chemicals.
What are the processes
involved in sewage treatment?
Sewage treatment includes:
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent
What do new methods of mining
avoid in terms of disadvantages of
traditional mining?
Avoids the disadvantages of traditional mining methods of digging, moving and
disposing of large amounts of rock
What is phytomining?
Phytomining uses plants to absorb metal compounds from the soil. The plants are
harvested and then burned to produce ash that contains the metal compounds
What is bioleaching?
Bioleaching uses bacteria to produce leachate solutions that contain metal
compounds.
What are the 3 advantages phytomining
Reduces the need for new ore by traditional mining
Conserves limiting supplies of high-grade ores
Reduces the amount of rock waste that must be disposed of after traditional mining.
What are the 3 advantages bioleaching
Bioleaching can stabilise sulphate toxins from the mine without causing harm to the environment.
Bioleaching is a relativley green process
It also doesn’t require land that already contains high concentrations of low grade ores.
What are the 3 didsadvantages bioleaching
produces toxins
Has sulfuric acid which damages the environment
What are the 3 didsadvantages phytomining
Plants growing on contaminated land absorb copper ions as they grow. These plants are harvested and burned, producing ash that contains high concentrations of copper
compounds.
A disadvantage of phytomining is that the process takes a lot longer than the classic methods
Describe the stages of LCAs
Life Cycle Assessments (LCAs) are carried out to assess the environmental
impact of products in each of these 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.
How do we reduce the use of resources?
The reduction in use, reuse and recycling of materials by end users reduces the
use of limited resources, energy consumption, waste and environmental impacts.
What are the advantages of recycling?
Advantages of recycling: less acid rain (pollution) metal ore reserves last longer /
conserved energy for extraction saved less mining / quarrying less waste less
landfill creates local employment
What are the disadvantages of recycling?
Disadvantages of recycling ; collection problems transport problems/ cost of
transport difficult to separate metal from appliances/sort
What is corrosion ?
Corrosion is the destruction of materials by chemical reactions with substances in
the environment, e.g. rusting.
how is corrosion prevented?
Corrosion can be prevented by applying a coating that acts as a barrier, such as
greasing, painting or electroplating. These methods stop the air or water coming
into contact with the metal.
Describe the sacrificial protection
Some coatings are reactive and may contain corrosion inhibitors or a more
reactive metal.
If two metals are in contact the more reactive metal will corrode instead of the less
reactive one, e.g. zinc is used to galvanise iron and when scratched, provides
sacrificial protection because zinc is more reactive than iron.
Describe the compounds and the uses of bronze
Bronze - an alloy of copper and tin, used for making statues and decorative objects.
