Formal assessment (using resources - paper 1)

Question 1

What do humans use the Earth’s resources to provide?

Answer 1

warmth
shelter
food
transport

Question 2

What does sustainable development do?

Answer 2

it meets the needs of the current generation without compromising the ability of future generations to meet their own needs

Question 3

What do natural resources supplemented by agriculture provide?

Answer 3

food
timber
clothing
fuel

Question 4

For humans, drinking water should have sufficiently low levels of _______ and _________

Answer 4

dissolved salts and microbes

Question 5

Why is potable water not pure water?

Answer 5

because it contains dissolved substances

Question 6

How is potable water made?

Answer 6

1) freshwater from a suitable source
2) passed through a filter bed to remove any solid particles
3) chlorine gas is added to kill any harmful microorganism
4) fluoride is added to drinking water to reduce tooth decay

Question 7

What can be used to sterilise the water?

Answer 7

Ozone and ultraviolet

Question 8

Where does the UK get fresh water from?

Answer 8

the rain that collects in the ground and in lakes and rivers

Question 9

What could we use if freshwater supplies are limited?

Answer 9

Seawater can be desalinated to produce pure water

this can be done by distillation or reverse osmosis
- both these processes use a lot of energy, making them expensive and no practical for producing large quantities of fresh water

Question 10

What happens in reverse osmosis?

Answer 10

the salty water is passed through a membrane that only allows water molecules to pass through.

Ions and larger molecules are trapped by the membrane so separated from the water

Question 11

What needs to be removed from wastewater?

Answer 11

organic matter, harmful microorganisms and toxic chemicals

Question 12

What are the steps for sewage treatment?

Answer 12

1) screening and grit removal
2) sedimentation to produce sewage sludge and effluent
3) aerobic biological treatment of effluent OR anaerobic digestion of sewage sludge

Question 13

What happens during sedimentation?

Answer 13

In a settlement tank, heavier suspended solids sink to the bottom to provide sludge while lighter effluent floats on the top

Question 14

What happens during Biological aerobic digestion?

Answer 14

effluent is removed from the settlement tank,

air is pumped through the water to encourage aerobic bacteria to break down any organic matter - including other microbes in the water

Question 15

What happens during anaerobic digestion?

Answer 15

sludge is removed from settlement tank and transferred into larger tanks.

Broken down by bacteria

Question 16

What are life cycle assessments (LCA) used to do?

Answer 16

assess the environmental impact of a product has over its whole lifetime

Question 17

What are the stages of LCA?

Answer 17

1) extracting and processing
2) manufacturing and packaging

3) use and operation during its lifetime
(how long the product is used for and what damage it does to the environment)

4) product disposal

Question 18

What does manufacturing and packaging in LCA assess

Answer 18

how much energy is used and how much pollution is caused when the product is being made

Question 19

What does product disposal in LCA assess

Answer 19

• whether the product is disposed of in a landfill site which takes up space and pollutes land and water
• how much energy is used to transport waste to landfill, which causes air pollutants
• whether the product will be incinerated which causes air pollution

Question 20

What does extracting and processing in LCA assess

Answer 20

• how much damage is caused when raw materials are extracted

- whether the extraction causes pollution due to the amount of energy needed

Question 21

How useful are LCAs

Answer 21

• use of water resources, energy sources and production of some wastes can be fairly easily quantified
• allocating numerical values to pollutant effect is less straightforward and requires value judgement, so LCA is not a purely objective process
• selected and abbreviated LCAs cab ve devised ti evaluate a product but these can be misused to reach pre-determined conclusions