# A student has collected a sample of muddy river water. Describe how the processes of sedimentation and filtration can be used to remove the solid particles from this water sample.

> Edexcel GCSE Chemistry (1CH0) — 2.2 Methods of separating and purifying substances · Describe · 4 marks

> River water often contains suspended solid particles such as sand and mud. These solids must be removed as part of water treatment before the water can become potable.

## Mark scheme (4 marks)

1. Sedimentation involves leaving the water so that suspended solids fall to the bottom of the container (forming a sediment)
2. Sedimentation allows the solid particles to be easily removed from the water
3. Filtration is used to separate the remaining insoluble solid particles from the water / the water passes through a filter
4. The solid particles are trapped / remain in the filter (as a residue) and the water passes through as the filtrate

## Key terms

- [sedimentation](https://www.gradenine.co.uk/glossary/sedimentation)
- [filtration](https://www.gradenine.co.uk/glossary/filtration)

## Related

- [Revision notes for Edexcel GCSE Chemistry (1CH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-has-collected-a-sample-fa038916) · Published by Druglandscape Ltd.