4.10.1 Using Earth's resources and potable water (will come up)

Question 1

What is sustainable development

Answer 1

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs

Question 2

In the UK potable water is produced by

Answer 2

Choosing an appropriate source of fresh water
Passing the water through filter beds to remove any solids
Sterilising to kill microbes

Question 3

What are the sterilising agents for potable water

Answer 3

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 it is more expensive

Question 4

How is desalination carried out

Answer 4

Desalination can be done by distillation or by processes that use membranes such as reverse osmosis
Theses processes require large amounts of energy

Question 5

What is reverse osmosis

Answer 5

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

Question 6

How is wastewater produced and treated

Answer 6

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

Question 7

What are the processes involved in sewage treatment

Answer 7

Screening and grit removal
Sedimentation to produce sewage sludge and effluent
Anaerobic digestion of sewage sludge
Aerobic biological treatment of effluent

Question 8

What do new methods of mining avoid in terms of disadvantages of traditional mining

Answer 8

Avoids the disadvantages of traditional mining methods of digging, moving and disposing of large amounts of rock

Question 9

What is phytomining

Answer 9

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

Question 10

What is bioleaching

Answer 10

Bioleaching uses bacteria to produce leachate solutions that contain metal compounds

Question 11

What are the main advantages and disadvantages of phytomining and bioleaching

Answer 11

They need less energy than traditional methods and can work on low concentration ores but are slow to carry out