Water

Question 1

What is potable water

Answer 1

Water you can drink however it isn’t pure as it contains other dissolved substances
pH between 6.5-8.5

Question 2

What process does water go though to be safe in the uk

Answer 2

Filteration (with wire mesh)

Sterilisation - chlorine ozone or ultraviolet light

Question 3

What do places where there’s not enough water do to make water safe

Answer 3

Treat by desalination through distillation

Reverse osmosis through membranes

Question 4

What is the first stage of sewage treatment

Answer 4

Screening
Removing any large bits of material
And grit

Question 5

What’s the second stage of sewage treatment

Answer 5

Sedimentation - The water is allowed to stand in a settlement tank and undergo sedimentation
The heavier solids sink to the bottom and produce sludge
The lighter effluent floats on top

Question 6

What happens to the effluent in the settlement tank

Answer 6

It’s removed and treated by biological aerobic digestion

Air is pumped through the water to encourage aerobic bacteria to break down any organic matter

Question 7

What happens to the sludge in the settlement tank

Answer 7

It’s removed and transferred into large tanks

It’s broken down by bacteria in anaerobic digestion

Question 8

What happens in anaerobic digestion in sludge

Answer 8

It breaks down the organic matter in the sludge and releases methane gas
This is used as an energy source and the remaining waste can be used as a fertiliser