Water Treatment
Water is made safe to drink by filtering it and adding chlorine, while sewage is treated to remove solids and harmful bacteria.
▶ Interact
Play with the controls to see the idea in action.
📘 Learn
Water is made safe to drink by filtering it and adding chlorine, while sewage is treated to remove solids and harmful bacteria.
- Filter beds remove solids
- Chlorine kills microbes
- Desalination uses distillation or reverse osmosis
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Water Treatment?
Within Chemistry, which covers atoms, bonding, reactions, the periodic table, organic chemistry and the chemistry of everyday life, this topic explains Water Treatment. Chemistry links what you can see in the lab to the particles and bonds behind it, so each topic here shows that link in a model.
Check that you can explain Water Treatment in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Water Treatment helps you explain why substances behave as they do, from cleaning products and food to medicines.
Water Treatment in detail
Drinking water must be safe. Water from reservoirs and rivers passes through screens to remove large objects, then sedimentation with chemicals that make particles clump, filtration through sand and gravel, and finally sterilisation with chlorine, ozone or ultraviolet light to kill microbes.
Where fresh water is scarce, sea water can be desalinated by distillation or reverse osmosis, which needs a lot of energy. Waste water goes through sewage treatment, including screening, settling and bacterial digestion, before it is returned to the environment. Clean water prevents diseases like cholera.
How the interactive helps you understand Water Treatment
Click a step, or use the Previous and Next buttons, to move through the sequence one stage at a time. Auto-play moves on for you.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Water Treatment.
Real-life uses and examples
- Read a chemical equation or diagram and work out what Water Treatment shows.
- Explain Water Treatment in an exam by linking the particles involved to what you observe.
- Use Water Treatment to explain what happens in a lab experiment and why.
Common mistakes to avoid
- Describing what happens without explaining the particles or bonds involved.
- Mixing up the names of substances or ions when you describe Water Treatment.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Water Treatment
What is Water Treatment?
Water is made safe to drink by filtering it and adding chlorine, while sewage is treated to remove solids and harmful bacteria.
What are the most important points about Water Treatment?
The main points are: Filter beds remove solids; Chlorine kills microbes; Desalination uses distillation or reverse osmosis.
Why is Water Treatment useful?
Understanding Water Treatment helps you explain why substances behave as they do, from cleaning products and food to medicines.
How can I practise Water Treatment?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Water Treatment?
Related topics in Chemistry include Atmospheric Pollution, Recycling and Life Cycle Assessment, Tests for Anions.