Potable water can be produced from fresh water sources such as rivers or lakes.
The typical processes used to treat this water include sedimentation, filtration, and sterilisation.
What is filtration?
Solid particles are allowed to settle to the bottom of a large tank.
Insoluble solids are removed by passing the water through layers of sand and gravel.
Chlorine or ozone is added to the water to destroy harmful microbes.
The water is boiled and the steam is condensed to separate it from dissolved salts.
107 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.