Water Treatment Flashcards
What is potable water?
Water that is drinkable.
What are the three places that we get our water from?
- Surface water
- Ground water
- Waste water
What is surface water?
Water from lakes, rivers and reservoirs.
What is ground water?
Water from aquifers (rocks that trap water underground).
What is waste water?
Water that’s been contaminated by a human process, and is treated to make it potable.
How pure are these water sources?
Ground water is usually quite pure, but waste water and surface water need a lot of treatment.
What are the processes of purifying water?
- Filtration
- Sedimentation
- Chlorination
In purification, what is filtration?
A wire mesh screens out large twigs etc., and then gravel and sand beds filter out any other solid bits.
In purification, what is sedimentation?
Iron sulfate or aluminium sulfate is added to the water, which makes fine particles clump together and settle at the bottom.
In purification, what is chlorination?
Chlorine gas is bubbled through to kill harmful bacteria and other microbes.
What other process CAN be used to produce potable water from seawater?
Distillation.
Why is distillation not used to produce potable water in the UK?
Because it needs loads of energy, so it’s really expensive.
What is deionised water?
Water that has had the ions (e.g. calcium, iron and copper ions) that are present in normal tap water removed.
Why is deionised water used in reactions?
Because the ions, although present in small amounts and harmless in tap water, can interfere with reactions, giving your experiment a false result.
