Potable Water Flashcards
(24 cards)
What does potable water mean?
Water which is safe to drink.
What is the other term for pure water?
Distilled water
What does pure water mean?
Water which has no dissolved substances in it.
In the UK, what is the main source of water?
Rainwater
Apart from rainwater, what are three other sources of water?
- Rivers
- Aquifers
- Reservoirs
In countries where water is scarce, what is the solution to provide a water source?
Boreholes reach water underground
True or false?
In the UK, rain provides water with high levels of dissolved substances.
False,
- Rain provides water with low levels of dissolved substances.
True or false?
In the UK, rain provides water with low levels of dissolved substances.
True
What are the three steps to produce potable water?
- Choose an appropriate source of fresh water.
- Pass the water through filter beds (made of sand + gravel).
- Sterilise using chlorine, ozone, or UV light.
How is water which has many impurities cleaned?
It is treated.
What are the two ways to desalinate water?
- Distillation
- Reverse osmosis
What type of decay does fluorine prevent?
Tooth decay
What does chlorine gas disinfect?
Water
What is the name of the process of chlorine disinfecting water?
Chorination
Is distillation expensive?
Yes
What is flash distillation?
When high pressure is used to lower the boiling temperature of water.
Does reverse osmosis use a membrane?
Yes
What does screening entail?
Screens of progressively finer mesh remove large chunks of solids.
What are the five processes of producing potable water?
- Screening
- Clarification
- Filtration
- Disinfection
- pH correction
What two things are removed during clarification?
Mud + silt
During clarification, what two things are added together to make sludge?
Alum + lime = sludge
In the UK, what are the two main steps to produce potable water?
- Filtration
- Sterilising
Why is chlorine added to water?
Kills bacteria
Potable water contains low levels of ___ and ___
salts and microbes.
