10.1 Using the Earth's resources and obtaining potable water 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
How is potable (safe to drink) water produced in the UK?
● An appropriate source of freshwater is chosen
● The water is passed through filter beds to remove any solids
● The water is sterilised to kill microbes
What sterilising agents are used
in 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 a 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?
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? (Higher)
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? (Higher)
Bioleaching uses bacteria to produce leachate solutions that contain metal
compounds.
What are the main advantages
and disadvantages of phytomining and bioleaching? (Higher)
These methods need less energy than traditional methods, and can work on low
concentration ores but are slow to carry out.
