| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Chemistry |
| Lesson Topic: Describe the treatment of the domestic water supply in terms of: (a) sedimentation and filtration to remove solids (b) use of carbon to remove tastes and odours (c) chlorination to kill microbes |
Learning Objective/s:
- Describe the processes of sedimentation and filtration used to remove suspended solids from domestic water.
- Explain how activated carbon adsorbs organic compounds to improve taste and odor.
- Outline the chemical reactions involved in chlorination and the factors that control disinfection efficacy.
- Compare the removal efficiencies of each treatment stage.
- Evaluate the importance of residual chlorine in maintaining water safety.
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Materials Needed:
- Projector or interactive whiteboard
- PowerPoint slides or digital presentation on water treatment
- Handout summarising each treatment stage
- Diagram of a sedimentation basin and a carbon filter
- Sample of activated carbon (optional demonstration)
- Worksheet with short‑answer questions
- Whiteboard and markers
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Introduction:
Begin with a quick video showing a murky river turning clear after treatment, prompting students to consider how water becomes safe to drink. Ask learners to recall any household water filters they have seen and what they think each stage does. Explain that by the end of the lesson they will be able to describe the key treatment steps and justify why each is necessary.
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Lesson Structure:
- Do‑now (5’) – Students list everyday sources of water contamination on a sticky note and share briefly.
- Mini‑lecture (10’) – Present sedimentation and filtration concepts using diagrams; highlight gravity settling and filter media.
- Guided demonstration (8’) – Show a simple sand‑filter model; students predict what will happen to coloured water.
- Interactive activity (10’) – Small groups analyse a flow‑chart of the treatment plant and label each stage’s purpose and equipment.
- Carbon adsorption discussion (7’) – Explain activated carbon; students match common organic pollutants to the adsorption process.
- Chlorination simulation (8’) – Use a virtual lab or animation to illustrate chlorine dosing, CT value and residual maintenance.
- Check for understanding (5’) – Quick quiz (Kahoot/handout) with one question per treatment stage.
- Summary recap (5’) – Teacher revisits learning objectives and asks students to give one real‑world example of each step.
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Conclusion:
Summarise how sedimentation, filtration, carbon adsorption and chlorination work together to produce safe drinking water. Ask each student to write one key takeaway on an exit ticket and hand it in. For homework, assign a short research task to find a local water treatment plant and describe which of the studied processes it uses.
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