Drinking Water Flashcards
What is the process of distilling salt water, to become drinking water?
- Salt water is put in
- Heated by solar energy
- Evaporates in glass dome
- Cools and condenses
- Pure water is taken out
Why is fractional distillation used?
It uses the different boiling points of different substances. For example, when separating substances in mixtures such as crude oil and water.
Impurities in water include…
At least 2 examples
- Leaves and twigs
- Insoluble particles (grit)
- Dissolved salts and minerals
- Pollutants (fertilisers)
- Bacteria and microbes
1) Coarse filtration
Water passes through coarse filter to remove twigs and leaves
2) Sedimentation
Added chemicals cause solid particle to clump together.
These may settle or filter
3) Fine filtration
Water is sprayed onto prepared layers of and and gravel
Removes different insolubles
4) Chlorination
Chlorine gas is injected into water and kills microbes
Why isn’t tap water used in labs?
Tap water contains dissolved salts.
These may give an incorrect result.
Instead, distilled or de-ionised water is used.
What are the two main processes to make drinking water safe?
Filtration
Chlorination
