C14.1-14.3 (Finite, Renewable Resources, Potable Water, Water Treatment)

Question 1

What do we rely on the Earth for?

Answer 1

For its natural resources to make new products and provide us with energy

Question 2

Finite

Answer 2

Resources that will run out eventually

if we continue to exploit them (e.g fossil fuels)

Question 3

Renewable

Answer 3

Resources that can be replaced as we use them up (e.g crops used to make biofuels)

Question 4

Give some examples of finite resources

Answer 4

-Metal ores (extract metal from)
-Crude oils (polymers and petrochemicals)
-Limestone (cement and concrete)
Crude Oil (petrol, diesel, kerosene)

Question 5

Sustainability

Answer 5

Developments that meet the demands of society now, without endangering the ability for future generation to meet their needs.

Question 6

E.g of renewable resources

Answer 6

• Polymers produced by ethene made from crude oil (ethene can instead come from ethanol by fermenting glucose form sugar cane or sugar beet)
• Wood chips to fuel power stations instead of crude oil

Question 7

Name one way water can be purified

Answer 7

Distilation

But requires large amounts of energy, expensive

Question 8

Explain the water treatment process from fresh water reservoirs

Answer 8

• Passed through a screen (consisting of close metal bars, catching large objects)
• Settlement tank- sand and soil settle out
• Aluminium sulfate and lime added (small particles dirt clump together, so they sink to the bottom of the water, the sludge that forms is collected and dumped in landfill as mud)
• Water passes through a special filter of fine sand and gravel (removing and remaining particles of mud or grit)
• Small amount of Chlorine or Ozone or UV light added to kill any remaining harmful bacteria
• pH then checked and altered if not nuterual

Question 9

What’s desalination

Answer 9

Converting salty water to potable, useable water

Question 10

What is an alternative method to distilation

Answer 10

Reverse osmosis, were the membranes are used to seperate the water particles and the salts dissolved in it (expensive process, used in middle east)

Question 11

What does waste water require before being put back into the environment

Answer 11

Treatment

Question 12

What does sewage treatment involve

Answer 12

Removal of organic matter and harmful microoganisms and chemicals

Question 13

Name stages of sewage treatment

Answer 13

Screening (remove large solids and grit)
Sedimentation (to produce sewage sludge)
Aerobic biological treatment of the safe effluent released into the environment

Sewage sludge seperated and broken down by anaerobic digestion and dried (used as a fertiliser and renewable energy)