Hygiene (Water Purification Demonstration) Basic 2 Physical & Health Education Lesson Note

Learning Objectives

At the end of the lesson, pupils should be able to: i. Demonstrate the process of purifying water ii. Explain how they purify water at home

Introduction

This week we will practice actually purifying water using safe methods we can do at school and at home. Learning to purify water properly is an important life skill that helps keep our families healthy.

Content

Preparing for Water Purification Demonstrations

Safety First:

• Always have an adult supervise when using heat or chemicals
• Use clean equipment and containers
• Wash hands before handling water purification materials
• Never drink water that hasn’t been properly purified
• Keep purification materials away from small children

Materials Needed for Demonstrations:

• Clean pots for boiling
• Heat source (stove, hot plate, or safe fire)
• Clean containers for storage
• Filtering materials (cloth, sand, stones, cotton)
• Clear plastic bottles
• Clean measuring cups and spoons

Demonstration 1: Boiling Water Method

Step-by-Step Process:

Preparation:

1. Collect water: Get water that needs purification
2. Check equipment: Make sure pot and stove are clean
3. Safety check: Adult supervision and safe workspace
4. Clean containers: Prepare storage containers

Boiling Process:

1. Pour water: Put water into clean pot, don’t fill completely
2. Heat source: Place pot on stove or heat source
3. Monitor heating: Watch water as it begins to warm
4. Identify boiling: Look for large bubbles rising rapidly to surface
5. Time boiling: Keep water boiling vigorously for 3 full minutes
6. Turn off heat: Remove pot from heat source safely
7. Cool down: Let water cool to room temperature
8. Store safely: Pour into clean, covered container

What to observe during boiling:

• Water temperature increases gradually
• Small bubbles appear first (not yet boiling)
• Large, rapid bubbles mean water is boiling
• Steam rises from boiling water
• Water may look clearer after boiling

Demonstration 2: Simple Water Filter Construction

Building a Basic Filter:

Materials needed:

• Large clear plastic bottle (2-liter size works well)
• Small stones or pebbles (clean)
• Coarse sand (washed)
• Fine sand (washed)
• Cotton balls or clean cloth
• Activated charcoal (if available)

Construction steps:

1. Prepare bottle: Remove cap and cut small holes in it
2. Layer 1: Put cotton or cloth in bottle neck (bottom layer)
3. Layer 2: Add layer of fine sand (2-3 inches)
4. Layer 3: Add layer of coarse sand (2-3 inches)
5. Layer 4: Add layer of small, clean stones (2-3 inches)
6. Test filter: Pour clean water through first to rinse
7. Ready to use: Filter is ready for dirty water

Using the filter:

1. Pour slowly: Add dirty water gradually to top
2. Watch flow: Water should drip steadily from bottom
3. Collect filtered water: Use clean container to catch water
4. Observe changes: Notice how water becomes clearer
5. Multiple passes: Filter water 2-3 times for better results

Demonstration 3: Solar Water Disinfection (SODIS)

Setting up SODIS:

Requirements:

• Clear plastic bottles (1-2 liters)
• Direct sunlight
• Flat, dark surface (metal sheet or dark cloth)
• Thermometer (if available)

Process:

1. Clean bottles: Wash bottles thoroughly inside and out
2. Fill with water: Use clear or slightly cloudy water only
3. Remove air: Fill bottles completely, no air bubbles
4. Position bottles: Lay on side in direct sunlight
5. Dark background: Place on dark surface to absorb heat
6. Time exposure: Leave for 6 hours in bright sun
7. Check temperature: Water should reach 50°C (122°F) if possible
8. Store safely: Keep bottles in shade after treatment

What happens during SODIS:

• UV rays from sun kill germs
• Heat from sun also kills harmful organisms
• Clear plastic allows maximum UV penetration
• Dark surface helps heat water faster

Home Water Purification Practices

Common Methods Used at Home:

1. Household Boiling:

• Most families boil drinking water daily
• Use clean pots and store in covered containers
• Boil water for tea, coffee, and cooking
• Cool boiled water before storing in refrigerator

2. Home Water Filters:

• Many homes use ceramic or carbon filters
• Some families have electric water purifiers
• Regular maintenance and filter replacement needed
• Combine filtering with boiling for extra safety

3. Buying Bottled Water:

• Purchase from reputable companies
• Check expiration dates and bottle condition
• Store bottles in cool, clean places
• More expensive but convenient option

4. Rainwater Collection and Treatment:

• Some families collect rainwater in clean containers
• Filter and boil rainwater before drinking
• Keep collection containers covered and clean
• First rain after dry period should be discarded

Teaching Family Members:

How to share water purification knowledge:

• Show parents and siblings what you learned
• Practice purification methods together
• Explain why clean water is important for health
• Help younger family members learn safe practices

Making Water Purification a Habit:

• Purify water every day, not just when someone is sick
• Always purify water from new or uncertain sources
• Check that storage containers are clean
• Replace filter materials when they become dirty

Troubleshooting Common Problems:

When boiling doesn’t seem to work:

• Make sure water reaches full boiling (big bubbles)
• Boil for full 3 minutes, not less
• Use clean pot and storage containers
• Don’t mix boiled water with unboiled water

When filtering isn’t effective:

• Clean or replace filter materials
• Filter water multiple times
• Combine filtering with boiling
• Use finer filtering materials for better results

Quality Testing:

• Purified water should be clear and odorless
• Should taste normal, not strange or bad
• No visible particles or floating matter
• When in doubt, use additional purification method

Activities

• Hands-on water boiling demonstration with teacher supervision
• Build and test simple water filters in small groups
• Set up solar water disinfection experiment (if weather permits)
• Compare water quality before and after purification
• Practice explaining purification methods to classmates
• Role-play teaching water purification to family members

Multiple Choice Exercise

1. When boiling water, we should see: a) Small bubbles b) Large bubbles rising fast c) No bubbles 
2. In a water filter, which goes at the bottom? a) Large stones b) Fine sand c) Cotton or cloth 
3. Solar water disinfection works best in: a) Rainy weather b) Bright sunlight c) Night time 
4. Filtered water should look: a) Clearer than before b) More cloudy c) Yellow 
5. At home, the most common way to purify water is: a) Using ice b) Boiling c) Adding sugar 

Answers: 1(b), 2(c), 3(b), 4(a), 5(b)