Lss module 2 chpt 7 water pollution

Module 2:
Matter Around Us
Chapter 7 Water Pollution
1© Copyright Star Publishing Pte Ltd

7.1 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?

Objectives
 Appreciate 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
© Copyright Star Publishing Pte Ltd 4
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.

water?
7.2 What are the sources and effects
of water pollution?
Singapore?

Objectives
 State common types and sources of
water pollution
 Investigate 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 Toxic
Industrial 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.

Litter
 Litter can affect water quality.
rusty metal drum
pollutes the sea and breeds
mosquitoes.
unwanted bottles and
cans in river
wastes such as plastic
bags 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.
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
Fertilisers
 Fertilisers 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 17

water?
water pollution?
Singapore?

Objectives
 Appreciate 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 in
Singapore
 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)

Desalination
 Desalination 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

water?
water pollution?
Singapore?

Objectives
 Discuss 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
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

Lss module 2 chpt 7 water pollution

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Lss module 2 chpt 7 water pollution

Similar to Lss module 2 chpt 7 water pollution (20)

More from Betsy Eng

More from Betsy Eng (14)

Recently uploaded

Recently uploaded (20)

Lss module 2 chpt 7 water pollution