C14 - The Earth's Resources

Question 1

define:

LCA

Answer 1

Life Cycle Assessment - analysis of a product’s entire lifecycle of the impact on the environment

‘cradle-to-grave’

Question 2

name:

4 stages of an LCA

Answer 2

1. raw material extraction
2. maufacture
3. use / maintenance
4. recycle / waste managment

Question 3

describe:

4 stages of sewage treatment

Answer 3

1. screening (filtering) - removes large particles
2. sedimentation - produces sludge and effluent
3. anaerobic treatment of sludge using bacteria
4. aerobic treatment of effluent using bacteria

Question 4

define:

potable water

Answer 4

water that is safe to drink

Question 5

describe:

producing potable water from fresh water sources

2 steps

Answer 5

1. passing water through filter beds to remove insoluable substances
2. sterilising water to kill microorganisms

Question 6

list:

2 methods of sterilisation

for producing potable water

Answer 6

• UV light
• chlorine
• ozone

Question 7

define:

desalination

Answer 7

prouducing potable water from salty water

Question 8

name:

2 methods of desalination

Answer 8

• distillation
• reverse osmosis