Water

Question 1

Potable water

Answer 1

Drinkable water that has dissolved impurities

Question 2

Pure water

Answer 2

100% H2O

Question 3

Waste water

Answer 3

Used water from homes,industry, and agriculture

Question 4

Sea water

Answer 4

Water in seas and oceans

Question 5

Groundwater/aquifer

Answer 5

Water in underground streams and lakes

Question 6

Making potable water from fresh water (4 marker)

Answer 6

• Screening: a grid acts like a sieve, removing large insoluble objects
• Sedimentation: small insoluble particles ‘settle out’ of the screened water source
• Filtration: very small, insoluble particles are filtered through increasingly fine layers
  -Sterilisation- Microbes (like bacteria) are killed with either chlorine, ultraviolet or ozone

Question 7

What are the two ways to make potable water from sea water?

Answer 7

Distillation and reverse osmosis

Question 8

Reverse osmosis

Answer 8

-A separation techniques used to obtain pure water from salt water
- Salt water is passed through a partially permeable membrane

Question 9

Distillation

Answer 9

Distillation is a process used to separate liquids based on their boiling points

Question 10

Waste water treatment stages

Answer 10

Grit removal
Primary sedimentation tanks
Aeration
Final settling tanks
Sludge treatment
Burners

Question 11

Step 1: Grit removal

Answer 11

Water passes through a series of screens and then a grit channel

Question 12

Step 2:Primary sedimentation tanks

Answer 12

The settling tank is used to settle suspended particles in water

Question 13

Step 3:Aeration

Answer 13

Oxygen is added to bacteria for treating and stabilising waste water

Question 14

Step 4:Final settling tanks

Answer 14

Useful bacteria sinks to the bottom

Question 15

Step 5: Sludge treatment

Answer 15

sewage sludge is digested anaerobically by specific bacteria

Question 16

Step 6: Burners

Answer 16

The sludge is collected and burnt to create heat, power and electricity