Using Resources Flashcards
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, how is potable water produced?
- choose an appropriate source of fresh water
- pass the water through filter beds to remove any solids
- sterilise 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 must be carefully monitored
- using ultraviolet light to kill microbes avoids adding chemicals to the water, but it’s 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 lifestyles and industrial processes produce large amounts of waste water that require treatment before being released into the environment
- sewage and agricultural waste water require removal of organic matter and harmful microbes
- industrial waste water may require removal of organic matter and harmful chemicals
What are the processes involved in sewage treatment?
- 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 o 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 is the main advantage and disadvantage of these methods (phytomining and bioleaching)?
these methods need less energy than traditional methods and can work on low concentration ores, but are slow to carry out
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 and disadvantages of recycling?
advantages:
- less acid rain (pollution)
- metal ore reserves last longer
- conserved energy for extraction saved
- less mining/quarrying
- less waste
- less landfill (sorry, pmt doesn’t believe in grammar)
- creates local employment
disadvantages:
- collection problems
- transport problems
- cost of transport
- difficult to separate metal from appliances
Describe the stages on LCAs
LCAs are carried out to assess the environmental impact of products in each of these stages (EMUD)
What is corrosion and how is it prevented?
corrosion is the destruction of materials by chemical reactions with substances in the environment, e.g. rusting
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 sacrificial protection
some coatings are reactive and may contain corrosion inhibitors or a more reactive metal
if 2 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 use of bronze
bronze - an alloy of copper and tin, used for making statues and decorative objects
Describe the compounds and the use of brass
an alloy of copper and zinc used for producing water taps and door fittings
Describe the compounds and the use of gold, silver, copper & zinc
gold used as jewelry is usually an alloy with silver, copper and zinc (the proportion of gold in the alloy is measured in carats, with pure gold being 24 carat, e.g. 18 carat gold is 75% gold)
Describe the compounds and the use of aluminum-magnesium
aluminum-magnesium alloys are low density and used in aerospace and manufacturing
Describe the compounds and the use of steels
alloys of iron that contain specific amounts of carbon and other metals, high carbon steel is strong but brittle, low carbon steel is softer and more easily shaped, steels containing chromium and nickel (stainless steels) are hard and resistant to corrosion
