10- Using The Earths Resources

Question 1

Potable water

Answer 1

• Water that can be drunk
  
  • low level of dissolved salts and microbes
• UK
  
  • rain water is used- low levels of dissolved substances (fresh water)
  • collects in ground, lakes and rivers

Question 2

Producing potable water

Answer 2

• choose an appopriate source of fresh water
• passing the water through filter beds
• sterilise
  
  • chlorine
  • ozone
  • uv

Question 3

How to produce potable water if limitd supply of fresh water

Answer 3

• desalination fo sea water
• requires lots of energy

-distillation
Or
-process w/ membranes eg. Reverse osmosis

Question 4

Waste water treatments

Answer 4

• large amounts produced from urban lifestyles and industrial processes
  
  • need treatment before releasing into environment

Question 5

Why need to treat industrial waste water

Answer 5

-remove organic matter and harmful chemicals

Question 6

Why need to treat sewage and agricultural waste water

Answer 6

-remove organic matter and harmful microbes

Question 7

Sewage treatment

Answer 7

• screening and grit removal
• sedimentation
  
  • produce sewage sludge and effluent
• anaerobic digestion of sewage sludge
• aerobic bacterial treatment of effluent

Question 8

Composites

Answer 8

-made up of two or more materials

Reinforcement- fibres/ fragments
Matrix- binds together

-properties of composite differs to each seperate material

Question 9

Fibre glass

Answer 9

Matrix- polymer
Reinforcement-glass fibre
-used in kayaks

Question 10

Natural wood

Answer 10

Matrix-lignin
Reinforcemennt0 cellulose fiibres
-uses wooden furnaitures

Question 11

MDF and plywood

Answer 11

Matrix-adhesives
Reinforcement-wood fibres

-flat pack furnaiture

Question 12

Carbon fibre composites

Answer 12

Matrix-polymer
Reinforcemet0 carbon fibre/nanotubes

-carbon fibre composites

Question 13

Concrete

Answer 13

Matrix-cement and water
Reinforcement- sand and stones

-uses- pavements

Question 14

Alloys

Answer 14

• mixture of two or more elements

- diff size atomes, distort regualr arrangemens cant slide over each other

Question 15

Bronze

Answer 15

-alloy of copper and tin

Question 16

Brass

Answer 16

Alloy of copper and zinc

Question 17

Gold

Answer 17

-cam be alloyed iwth silver, copper or zinc

Percentage = carat numberx100/24

Question 18

Steels

Answer 18

Alloy of iron, carbon and other metals

Question 19

High carbon steel

Answer 19

-strong but brittle

Question 20

Low carbon steel

Answer 20

• softer more maleable

- car body work

Question 21

Stainless steel

Answer 21

• steel w/ chromium, nickel

- hard, resistant to corroion

Question 22

Alluminium alloy

Answer 22

-low density

Question 23

Clay ceramic

Answer 23

• brittle, unreactive
• wet clay baked in kiln/furnaces
• hard but britt;e
• unreactive, resistant too heat
• useful in bricks and crockery

Question 24

Ceramic

Answer 24

• non metal solids
• w/ high mp
• not. Made from carbon based composites
  
  • eg, clay and glass

Question 25

Glass

Answer 25

-brittle, transparent Two types -soda lime glass Boresilicate glass

Question 26

Soda lime glass

Answer 26

- made form sand, calcium carbonate, sodium carbonate - used in bottles, windows - most common

Question 27

Boresilicate glass

Answer 27

- made from sand, boron trioxide - used in cooking trays, ovenware, test tbes - particles not in regular arrangemet - high mp than soda lime glass

Question 28

Phytomining

Answer 28

- plants grow in low level of metal conc - abosorb metal - plants burnt - ash contains metal compounds - react ash w/ dilute sulfuric acid - solid copper formed by electrolysis solution/ displacementby uron

Question 29

Bioleaching

Answer 29

- bacteria breaks down low-grade ores - produces acidic solution and copper ions - leachate

Question 30

Why use biological methods of metal extraction

Answer 30

-avoids traditional mining methods of digging and desposing of large amounts of rocks

Question 31

Low copper ores

Answer 31

- recycling scrap copper requires less energy than processing ores - copper ore finite resource 0 by recycling scrap copper- copper lasts longer - processing copper ores using carbon produces co2- greenhouse gas so contributing to climate change - waste from copper ore extraction-landfill damages ecosystem

Question 32

Life cycle assessments

Answer 32

- used to assess the impact on the environment by using - getting and processing the raw material - making the product and any packaging - using, reusing and maintaining the product - disposing of a product at the end of its useful life

Question 33

Problems with LCA

Answer 33

- dont include effects of pollutants - eg. Negative visual effect plastic bag - can be biased - selective LCAs-only show some impurities

Question 34

Glass recycling

Answer 34

-glass bottles can be reused w/out reshaping OR -glass seperated by colour and chemical composition -crushed -melted -reshaped into bttles/jars/ insulting glass wool- home insulation