Download - Lss module 2 chpt 7 water pollution
Module 2: Matter Around UsChapter 7 Water Pollution
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Chapter 7 Water Pollution7.1 Why is it important to have
clean water? 7.2 What are the sources and
effects of water pollution?7.3 What are the sources of water
for Singapore? 7.4 How can water pollution be
prevented and reduced?
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ObjectivesAppreciate that water is a
precious resource that can be polluted as a result of Man's activities)
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Why is water important?Water supports life
processes.
(a) We need to have enough water, especially in countries with a hot climate like Singapore.
(b) Water cools our body and helps to transport substances through our blood circulatory system
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extreme dehydration can lead to death
Why is water important?
(b) Water cools our body and prevents heat stroke.
(c) Plants need water to make food. Plants without water will wither.
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Why is clean water important?
Clean water is used as bottled water.
It is crucial that clean water is used in saline solution to hydrate patients
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Clean water is important for food and medical industries to produce food and medicine that is safe for people to consume.
Why is clean water important?
Clean water used for drinking
Clean water used in cooking
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Clean water is important at home for cooking and drinking.
In school, we will need to drink water to stay hydrated for Physical Education (PE) classes.
Chapter 7 Water Pollution7.1 Why is it important to have
clean water? 7.2 What are the sources and
effects of water pollution?7.3 What are the sources of water
for Singapore? 7.4 How can water pollution be
prevented and reduced?
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ObjectivesState common types and sources
of water pollutionInvestigate the effects of water
pollution on living things
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Water pollution
Water can be easily polluted because it is a good solvent.
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Sources of water pollution
Some sources of water pollution include:
(a) untreated industrial waste and sewage,(b) litter,(c) oil spills,(d) runoffs from pesticides and fertilisers
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industrial chemicals contaminate water
Activity Book Link Activity 7.2 Sources of Water Pollution
Discharge of Untreated ToxicIndustrial Waste and Sewage
Untreated sewage pollutes river
Untreated Industrial waste water discharged into seas
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Toxic waste from factories kill the aquatic plants and animals and affect people who eat them.
Untreated sewage contain harmful disease-carrying bacteria which can cause people to become very ill.
LitterLitter can affect water quality.
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rusty metal drumpollutes the sea and
breedsmosquitoes.
unwanted bottles and
cans in river
wastes such as plasticbags can suffocate and kill
aquatic animals
Oil Spills
Oil spills can severely affect the lives of aquatic plants and animals.
Oil forms a layer on the water surface and prevents the air from entering the water.
The aquatic animals die due to the lack of oxygen. © Copyright Star Publishing
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workers removing oil from their
boats as oil spill is contained by barriers
Effects of oil spills
Oil may clog up the gills of fishes and cause them to die.
Oil, when coated on the feathers of sea birds, can affect their ability to fly and keep warm.
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Activity Book Link Activity 7.3 Effect of Oil Spills on Plant Lives
Runoffs from Pesticides and FertilisersFertilisers and
pesticides, being very soluble in water, can be easily washed by rain into rivers, lakes and seas.
They are poisonous to aquatic animals and can cause them to die.
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Activity Book Link Activity 7.4 Impact of Water Pollution on Living Things
Runoffs from Pesticides and Fertilisers
The runoff of fertilisers can cause algae to grow rapidly on the water surface. This prevents sunlight from reaching the bottom of the pond.
Aquatic plants cannot photosynthesise and eventually, this causes the oxygen levels in the water to decrease. © Copyright Star Publishing
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Chapter 7 Water Pollution7.1 Why is it important to have
clean water? 7.2 What are the sources and
effects of water pollution?7.3 What are the sources of
water for Singapore? 7.4 How can water pollution be
prevented and reduced?
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ObjectivesAppreciate that preventing water
pollution is essential if Singapore is to have a clean supply of water in the future
Appreciate that used water can be converted into drinkable water (e.g. NEWater) so as to provide Singapore with an additional source of water supply.
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Sources of Drinkable Water inSingapore We obtain our drinking water from four sources.
The four national taps are:
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NEWater
NEWater is produced by converting waste water into drinking water and for industrial uses.
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Bottles of NEWater
Recycling Waste Water (NEWater)
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DesalinationDesalination converts
salt water into fresh water. The seawater is evaporated and the vapour is condensed to produce drinkable water.
Desalination is more expensive because a large amount of energy is required to heat up and evaporate the seawater.
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Seawater is channelled into
the desalination plant to be purified into
drinking water
Chapter 7 Water Pollution7.1 Why is it important to have
clean water? 7.2 What are the sources and
effects of water pollution?7.3 What are the sources of water
for Singapore? 7.4 How can water pollution be
prevented and reduced?
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ObjectivesDiscuss some methods of water
pollution control
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How can we prevent water pollution?
To prevent activities that can pollute water, we can do the following:
(a) educate the public through campaigns on the importance of clean waterways(b) enforce laws to prevent people and industries from polluting our waterways© Copyright Star Publishing
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warning sign against dumping in Waterways
Sample poster for a 'Keep the Waterways Clean' campaign
Clearing up rubbish washed onto the beach
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How do we reduce the effects of water pollution?To reduce the effects of water
pollution, we can:
(a) clean up polluted beaches and rivers(b) provide bins along waterways(c) clear rubbish-clogged rivers, drains and canals
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Activity Book Link Activity 7.5 Control of Water Pollution
trash bin at Pasir Ris Beach
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