FORM 2 CHAPTER 5 WATER AND SOLUTION

Water As A Universal Solvent

• Due to its ability to dissolve almost all substances, solids,
liquids or gases

Water As A Universal Solvent

• Water – solvent in domestic used

– raw material in manufacturing industry, agriculture
and medicine

Fertiliser
dissolve
in water

Water As A Universal Solvent

• Water – solvent in domestic used

– raw material in manufacturing industry, agriculture
and medicine

Soft drinks
are produced
using water as

a solvent

Water As A Universal Solvent

• Water – solvent in domestic used

– raw material in manufacturing industry, agriculture
and medicine

Water dissolves
detergents
used in
cleaning
process

5.3 WATER PURIFICATION AND WATER SUPPLY

WATER PURIFICATION METHOD

1.Filtration
2.Boiling and chlorination
3.Distillation

Filtration

FILTRATION

ADVANTAGE
-Separate suspended particle

DISADVANTAGE
- Not remove microorganism
- Not remove salt

BOILING / CHLORINATION

ADVANTAGE
-Kill microorganism
-safe for drinking

DISADVANTAGE
- Unable to remove any
suspended particle

Example of
Suspended
particle in

water

Distillation

DISTILLATION

ADVANTAGE
- separate suspended

particle
- dissolved substances
- Kill microorganism

DISADVANTAGE
- Not safe for drinking

Solving The Problems Of Water Supply

Singapore has
limited water

supply.

NEWater Project

NEWater – modern technologies to recycle

sewage into drinking water and industrial uses

WATER SUPPLY SYSTEM

USAGE OF Industrial
WATER use

Direct use Domestic
of water Agriculture use

Water source



1. Water reservoir

2. Filtration

Metal screen
remove

large objects
such as

leaves, tree
branches

etc.

3. Oxidation

Water pumped
upwards
 to dissolve oxygen
 remove unpleasant
taste and smell

4. Coagulation

Alum

 Makes small particle stick
together

 Forming large lumps (sink
to the bottom faster)

Slaked Lime

 Reduce acidity of water

5. Sedimentation

Large
lumps are
removed

6. Filtration

Remove
remaining

solid
particles

7. Chlorination and fluoridation

Chlorine

 Kill harmful
microorganism

Fluoride

 Prevent dental
decay

8. Clean water tank



Water Sustainability







DOMESTIC

WASTE

Ways to overcome:

- Upgrade sewerage
system

- Educate people
- Improve sanitation

facilities in rural area

INDUSTRIAL
WASTE

Ways to overcome:

Enforce laws

to ensure industrial waste
is treated before being
discharged into the river

AGRICULTURA
L WASTE

Ways to overcome:
Educate farmers

to use biodegradable
fertilisers and
pesticides

OIL

SPILLAGE

Ways to overcome:

- surround and contain oil
spilled at sea using National
Oil Spill Contigency Plan
Revised Year 1999/2000

- Improve air surveillance
with the cooperation of Air
Police Unit