Paper 1: Drinking Water Flashcards
What must potable drinking water have?
Low levels of contaminating substances
Low levels of microbes
What are the main stages in water treatment?
1) sedimentation
2) filtration
3) chlorination
What happens during sedimentation in water treatment?
Large insoluble particles sink to the bottom of a tank
What happens during filtration in water treatment?
Small insoluble particles are removed by filtering through beds of sand
What happens during chlorination in water treatment?
Chlorine gas is bubbled from the water to kill microbes
How can sea water be made potable?
Filtered sea water is boiled
Water vapour is cooled and condensed to from distilled water
What are the positives of distillation?
Uses a plentiful of raw materials
Produces pure water
Kills microbes in the sea water
What is the disadvantages of distillation?
Needs a lot of energy to heat the water
