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?


ObjectivesAppreciate that water is a

precious resource that can be polluted as a result of Man's activities)


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


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.


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


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


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.







ObjectivesState common types and sources

of water pollutionInvestigate the effects of water

pollution on living things


Water pollution

Water can be easily polluted because it is a good solvent.


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


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


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.


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.


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.


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

Pte Ltd



effects of water pollution?7.3 What are the sources of

water for Singapore? 7.4 How can water pollution be



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.


Sources of Drinkable Water inSingapore We obtain our drinking water from four sources.

The four national taps are:


NEWater

NEWater is produced by converting waste water into drinking water and for industrial uses.


Bottles of NEWater

Recycling Waste Water (NEWater)


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.


Seawater is channelled into

the desalination plant to be purified into

drinking water







ObjectivesDiscuss some methods of water

pollution control


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


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


Activity Book Link Activity 7.5 Control of Water Pollution

trash bin at Pasir Ris Beach
