Topic 10: Using Resources

Question 1

What is potable water?

Answer 1

Water that has been treated or is naturally safe for consumption

Question 2

Why isn’t potable water called pure water?

Answer 2

Pure water contains only H2O while potable water can contain other dissolved substances

Question 3

Sewage Treatment (5)

Answer 3

1) Screening - removing large materials and grit
2) Sedimentation - heavier solids sink to make sludge while light lighter effluent floats
3) Effluent — Aerobic Digestion - aerobic bacteria break down organic matter and other microbes
4) Sludge — Anaerobic Digestion - bacteria in large tanks break down organic matter releasing methane gas
5) Further treatment - UV radiation, other chemicals or membranes are used to treat toxic chemicals

Question 4

Sources of waste water (3)

Answer 4

1) Domestic sources - water from baths, toilets and washing up
2) Agricultural sources - nutrient run-off and slurry
3) Industrial processes - waste water, harmful chemicals (need additional treatment)

Question 5

Life Cycle Assessments

Answer 5

Assessment of every stage of a product’s life and their environmental impact

Question 6

The 4 Stages of LCAs

Answer 6

1) Extraction and processes to acquire raw materials
2) Manufacturing and packaging
3) Product use
4) Product disposal

Question 7

Problems of LCAs

Answer 7

1) Can’t be easily quantified
2) Biased or at least not objective
3) Can be selective and used for false positive advertising

Question 8

Sustainable development

Answer 8

Development that takes care of present needs while not damaging future lives

Question 9

Reducing the use of finite resources (2)

Answer 9

1) Use less

2) Develop processes that use less finite resources like catalyst

Question 10

Bioleaching

Answer 10

Bacteria convert copper in ore into a soluble copper solution called a leachate which can then be extracted by electrolysis

Question 11

Phytomining

Answer 11

The accumulation of copper in plants growing in copper-rich soil which once burnt creates ash with soluble copper compounds

Question 12

Why should we recycle?

Answer 12

Reduces the use of finite resources and preserves them
Recycling uses less energy than extracting new raw materials
Recycling has a smaller environmental impact than extracting new raw materials
Minimises the waste created during disposal
Increases cost efficiency

Question 13

Recycling glass (5)

Answer 13

1) Collect used glass
2) Crush
3) Heat to 1000•c until it melts
4) Reshape in mould or blown
5) Cool

Question 14

Recycling metal (aluminium)

Answer 14

Scrap aluminium
Feed conveyor
Shredder
Decorate
Melting furnace - tilting holding furnace
Filtration unit
Direct chill casting unit - reshaping
Shredder

Question 15

What are the sources of freshwater in the UK (2)

Answer 15

1) Surface water - lakes, rivers and reservoirs (evaporates in warm places)
2) Groundwater - water trapped underground by rocks called aquifers (most of domestic water supply)

Question 16

Treatment of freshwater (2)

Answer 16

1) Filtration:
wire mesh - screens out large twigs
gravel and sand beds - filter out any solid bits
2) Sterilisation:
bubbling chlorine/ozone through water - kills harmful bacteria
UV light - kills harmful bacteria

Question 17

Sources of potable water in Kuwait

Answer 17

Seawater treated by desalination/membranes

Question 18

DESALINATION PRACTICAL

Answer 18

-

Question 19

Membranes (2) (REVERSE OSMOSIS)

Answer 19

Salty water passed through =

1) water molecules pass through
2) ions and large molecules trapped by membrane

Question 20

Problems with distillation and membranes (3)

Answer 20

1) Require lots of energy
2) Very expensive
3) Not practical for producing large quantities of water

Question 21

Why might sewage treatment be better than desalination for producing potable water?

Answer 21

Sewage treatment uses less energy than desalinating sea water - alternative for places without fresh water

Question 22

Why is freshwater treatment better than sewage treatment for producing potable water?

Answer 22

1) Sewage treatment requires more processes than treating fresh water
2) People don’t want to drink water previously sewage

Question 23

Drawbacks of mining (3)

Answer 23

1) Produces a lot of noise, air pollution and waste
2) Scars landscape
3) Destroys habitats which reduces biodiversity

Question 24

Benefits of recycling metal (4)

Answer 24

1) Fewer waste rock heaps
2) Less energy used
3) Conserves finite resources
4) Less burning of fossil fuels