Water Purification
Basic Science and Technology
Primary 3.
2nd Term
Second term
Scheme of work with lesson note
Week: Seven
Class:Primary Three
Topic: Water Purification (Making water fit for drinking)
Behavioural objectives: At the end of the lesson, pupils should be able to:
1. explains the meaning of purification of water.
2. describe how distillation process can purify water.
3. explains the meaning and ways of filtration.
4. explains boiling of water a method of purifying water.
5. name and explain how to keep the sources of water clean.
Instructional material/Reference material: Alum Disinfectant e.g. Izal, Dettol, TCP, Miltton solution, Muddy water, Container, Clean white cloth, Stove.
Building Background /connection to prior knowledge: pupils are familiar with Water Contaminants which was the last topic that was taught
Content:
Distillation of Water: Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, distilled water is one type of purified water. A water distillation system is designed to purify water cheaply, quickly and effectively. To distill water, all you really need is a heat source .
Water Filtration: Water filtration is a general term that refers to any system or process that is used to filter out particles and pollutants. Water filtration is the process of removing or reducing the concentration of particulate matter,including suspended particles, parasites, bacteria, viruses, and fungi, as well as other undesirable chemical and biological contaminants from contaminated water to produce safe and clean water for a specific purpose.
Boiling of water: Boiling water means that on heating water has reached maximum temperature and temperature of water cannot be raised further or The process of changing the state of a substance from liquid to gas by heating it to its boiling point.
Sources of water:
1. Rain
2. Well
3. Tap
4. Spring
5. Lake
6. River
7. Sea
8. Ocean
How to keep the source of water clean
1. Handle and dispose of waste properly:
– Reduce your waste production
-Use local hazardous waste collection programs
– Pick up pet waste
2. Maintain heating oil tanks and fill lines:
– Inspect your oil tank regularly
– Upgrade to a modern fuel tank
– Install a drip pan and oil line/gauge protectors
3. Maintain and use septic systems properly:
– Know the location of your tank and septic beds and protect it from damage
– Have the tank pumped out every three to five years
– Conserve water
Avoid the use of bleach/harsh cleaning products
4. Maintain wells:
– Inspect your well at least once a year
– Keep potential pollutants (i.e. livestock, septic systems, fuel sources, gardens) away from your well
– Test your well water regularly for bacterial contamination
5. Practice water conservation:
– Use a rain barrel to water your garden
– Install low flow shower heads and toilets
– Fix leaking taps
6. Use green products for:
– Household cleaning
– Personal care
– Lawn care
How Distillation process can purify water:
Distillation relies on evaporation to purify water. Contaminated water is heated to form steam. Inorganic compounds and large non-volatile organic molecules do not evaporate with the water and are left behind. The steam then cools and condenses to form purified water.
How to purify water by boiling:
Boil water, if you do not have bottled water. Boiling is sufficient to kill pathogenic bacteria, viruses and protozoa (WHO, 2015). If water is cloudy, let it settle and filter it through a clean cloth, paper boiling water towel, or coffee filter. Bring water to a rolling boil for at least one minute.
Presentation : The topic is presented to the young learners step by step
Step 1 : The class revises the previous topic
Step 2 : Introduction Of the new lesson
Step 3 :Allow learners to give their own ideas and suggestions
Evaluation: The teacher asked questions on what has been taught.
1. explains the meaning of purification of water.
2. describe how distillation process can purify water.
3. explains the meaning and ways of filtration.
4. explains boiling of water a method of purifying water.
5. name and explain how to keep the sources of water clean.