C14.1-14.3

Question 1

Is potable water pure?

Answer 1

Potable water is not pure as it contains lots of other dissolved substances

Question 2

What are sterilisng agents for potable water?

Answer 2

Filtration - wire mesh used to filter out solid bits
Chlorine used to kill harmful bacteria or microbes
Ultraviolet light used to kill microbes

Question 3

How is desalination carried out?

Answer 3

It can be done by using reverse osmosis which requires a large amount of energy which makes it exspenisve

Question 4

What is desalination?

Answer 4

Its used in dry countries to provide potable water by reverse osmosis

Question 5

What is reverse osmosis?

Answer 5

Sea water is passed theough a membrane that only allows through the water molecules. It needs high pressure to push the water through the membrane, the high pressure requires a lot of energy

Question 6

How is wastewater produced?

Answer 6

Indrustrial processes
Agricuktural waste
Sewage waste

Question 7

What happens in the first part(screening) of sewage treatment?

Answer 7

1) remove large solid objects and grit from the rest of the waste water.
2) sewage passes through a metal grid that traps large objects

Question 8

What happens in the second part(primary treatment) of sewage treatment?

Answer 8

sedimentation allows tiny particles to settle out from still water, which produces sewage sludge and effluent

Question 9

What happens in the third part(secondary treatment) of sewage treatment?

Answer 9

1)the sewage sludge is digested anaerobically by specific bacteria

Question 10

What happens in the final part (final treatment) of sewage treatment?

Answer 10

1) the effluent is treated with aerobic bacteria to reduce the volume of solid waste, at this point waste water is safe enough to be discharged back into rivers